The WildEarth Guardians (WEG) in 2010 requested that NMFS list six sawfish species as endangered. NMFS published a finding that it may be warranted in 2011. This is their latest report regarding sawfish, which they state are located everywhere.
We, NMFS, have completed comprehensive status reviews under the Endangered Species Act (ESA) of five species of sawfishes in response to a petition to list six sawfish species. In our 90-day finding we determined that Pristis pristis, as described in the petition, was not a valid species and began our status review on the remaining five species (Anoxypristis cuspidata; Pristis clavata; Pristis microdon; Pristis zijsron; and all non-listed population(s) of Pristis pectinata). During our status review, new scientific information revealed that three previously recognized species (P. microdon, P. pristis, and P. perotteti) were in fact a single species, Pristis pristis. We had previously listed P. perotteti as an endangered species (July 12, 2011). We therefore also considered the information from our 2010 status review of P. perotteti, herein P. pristis. We have determined, based on the best scientific and commercial data available and after taking into account efforts being made to protect the species, that the narrow sawfish (A. cuspidata); dwarf sawfish (P. clavata); largetooth sawfish (collectively P. pristis; formerly P. pristis, P. microdon, and P. perotteti); green sawfish (P. zijsron); and the non-listed population(s) of smalltooth sawfish P. pectinata meet the definition of an endangered species. We also include a change in the scientific name for largetooth sawfish in this proposed rule to codify the taxonomic reclassification of P. perotteti to P. pristis. We are not proposing to designate critical habitat because the geographical areas occupied by the species are entirely outside U.S. jurisdiction and we have not identified any unoccupied areas that are currently essential to the conservation of any of these species. We are soliciting information that may be relevant to these listing and critical habitat determinations, especially on the status and conservation of these species.
Comments on this proposed rule must be received by August 5, 2013. Public hearing requests must be made by July 19, 2013.
ADDRESSES: You may submit comments, identified by the following
document number, NOAA-NMFS-2011-0073, by any of the following methods:
Electronic Submissions: Submit all electronic public
comments via the Federal eRulemaking Portal. Go to www.regulations.gov/#!docketDetail;D=NOAA-NMFS-2011-0073. click the ``Comment Now'' icon,
complete the required fields, and enter or attach your comments.
Fax: 727-824-5309; Attn: Assistant Regional Administrator
for Protected Resources.
Instructions: You must submit comments by one of the above methods
to ensure that we receive, document, and consider them. Comments sent
by any other method, to any other address or individual, or received
after the end of the comment period may not be considered. All comments
received are a part of the public record and will generally be posted
for public viewing on http://www.regulations.gov without change. All
personal identifying information (e.g., name, address, etc.)
confidential business information, or otherwise sensitive information
submitted voluntarily by the sender will be publicly accessible. We
will accept anonymous comments (enter ``N/A'' in the required fields if
you wish to remain anonymous). Attachments to electronic comments will
be accepted in Microsoft Word, Excel, or Adobe PDF file formats only.
You can obtain the petition, the proposed rule, and the list of
references electronically on our NMFS Web site at http://sero.nmfs.noaa.gov/pr/pr.htm.
FOR FURTHER INFORMATION CONTACT: Shelley Norton, NMFS, Southeast
Regional Office (727) 824-5312 or Dr. Dwayne Meadows, NMFS, Office of
Protected Resources (301) 427-8403.
SUPPLEMENTARY INFORMATION:
Background
On September 10, 2010, we received a petition from the WildEarth
Guardians (WEG) requesting we list six sawfish species: knifetooth,
narrow, or pointed sawfish (A. cuspidata, hereinafter the narrow
sawfish); dwarf or Queensland sawfish (P. clavata, hereinafter the
dwarf sawfish); largetooth sawfish (P. pristis and P. microdon); green
sawfish (P. zijsron); and the non-listed population(s) of smalltooth
sawfish (P. pectinata) as endangered or threatened under the ESA; or
alternatively to list any distinct population segments (DPS) that exist
under the ESA. On March 7, 2011, we published a 90-day finding (76 FR
12308) stating the petitioned action may be warranted for five of the
six species A. cuspidata, P. clavata, P. microdon, P. zijsron, and the
non-listed population(s) of P. pectinata. Information in our records
indicated that P. pristis as described in the petition, was not a valid
species. Our 90-day finding requested information to inform our
decision, and announced the initiation of status reviews for the five
species. During the comment period we received five public comments.
We are responsible for determining whether species are threatened
or endangered under the ESA (16 U.S.C. 1531 et seq.). To make this
determination, we first consider whether a group of organisms
constitutes a ``species'' under the ESA, then whether the status of the
species qualifies it for listing as either threatened or endangered.
Section 3 of the ESA defines a ``species'' as ``any subspecies of fish
or wildlife or plants, and any distinct population segment of any
species of vertebrate fish or wildlife which interbreeds when mature.''
Section 3 of the ESA further defines an endangered species as ``any
species which is in danger of extinction throughout all or a
significant portion of its range'' and a threatened species as one
``which is likely to become an endangered species within the
foreseeable future throughout all or a significant portion of its
range.'' Thus, we interpret an ``endangered species'' to be one that is
presently in danger of extinction. A ``threatened species,'' on the
other hand, is not presently in danger of extinction, but is likely to
become so in the foreseeable future (that is, at a later time). In
other words, the primary statutory difference between a threatened and
endangered species is the timing of when a species may be in danger of
extinction, either presently (endangered) or in the foreseeable future
(threatened). Section 4(a)(1) of the ESA requires us to determine
whether any species is endangered or threatened due to any one or a combination of
the following five factors: (A) The present or threatened destruction,
modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence. We are required to make listing
determinations based solely on the best scientific and commercial data
available after conducting a review of the status of the species and
after taking into account efforts being made by any state or foreign
nation to protect the species.
In making listing determinations for these five species, we first
determine whether each petitioned species meet the ESA definition of a
``species''. Next, using the best available information gathered during
the status reviews, we complete an extinction risk assessment using the
general procedure of Wainwright and Kope (1999). We then assess the
threats affecting the status of each species using the five factors
identified in section 4(a)(1) of the ESA.
Once we have determined the threats, we assess efforts being made
to protect the species to determine if these conservation efforts were
adequate to mitigate the existing threats. We evaluate conservation
efforts using the criteria outlined in the joint NMFS and U.S. Fish and
Wildlife Service (USFWS) Policy for Evaluating Conservation Efforts
(PECE; 68 FR 15100; March 28, 2003) to determine their certainty of
implementation and effectiveness for future or not yet fully
implemented conservation efforts. Finally, we re-assess the extinction
risk of each species in light of the existing conservation efforts.
Status Reviews
In order to conduct a comprehensive review, NMFS Southeast Region
Protected Resources Division and NMFS Southeast Fisheries Science
Center, Panama City Laboratory, staff members collaborated to identify
the best available information. Unlike some previous 12-month findings
from this agency, we have not developed a separate status review
report. Instead, we present all information available for these species
in this Federal Register notice; we first discuss background
information relative to all five species and then include descriptions
of the natural history specific to each species.
Sawfish General Species Description
Sawfishes are a group of shark-like rays. Taxonomically they are
classified in the Family Pristidae (sawfishes), Order Rajiformes
(skates, rays, and sawfishes) and Class Chondrichthyes (cartilaginous
fish), also commonly known as elasmobranchs. The overall body form of
sawfishes is similar to sharks, but they are flattened dorso-ventrally.
Sawfishes are covered with dermal denticles (teeth-like scales) and
possess enlarged pectoral fins.
The most distinct characteristic of sawfishes is their large, flat,
toothed rostrum or `saw' with large teeth on each side. The rostral
teeth are made from calcified tissue that is neither dentin nor enamel,
though it is more similar to the latter (Bradford, 1957). Rostral teeth
develop inside sockets on the rostrum and are held in place by strong
fibers. Unlike sharks, sawfish rostral teeth are not replaced, although
partially broken teeth may continue to grow (Miller, 1974). For some
species of sawfish, the number of rostral teeth can vary by geographic
region.
Sawfishes use their rostrum to locate, stun, and kill prey,
generally small schooling fishes such as mullet, herring, shad, and
sardines (Bigelow and Schroeder, 1953). Breder (1952), in summarizing
the literature on observations of sawfish feeding behavior, noted that
they attack fish by slashing sideways through schools of fish, and then
impale the fish on their rostral teeth. Prey are subsequently scraped
off their rostral teeth by rubbing the rostrum on the bottom and then
ingesting the whole fish. Bigelow and Schroeder (1953) also report that
sawfish feed on crustaceans and other benthic species. Recent studies
indicate that sawfishes may use their toothed rostrum to sense their
prey's electric fields (Wueringer et al., 2011; 2012).
All sawfish species are distributed primarily in circumtropical
shallow coastal waters that generally vary in salinity. While sawfishes
are commonly found in shallow water, adults are known to also inhabit
deeper waters (greater than 130 ft, 39.6 m). Some sawfishes are found
in freshwater, with established populations in major rivers and lakes
of South America, Africa, and southeast Asia. The physical
characteristics of habitat, such as salinity and temperature, likely
influence a sawfish's movement patterns. Tides limit the physical
habitat area available, which may explain movement into shallow water
areas during specific tidal cycles (Blaber et al., 1989).
Life history data on sawfishes are limited. Fertilization is
internal by means of male claspers and reproduction is ovoviviparous;
females carry eggs with a yolk sac that nourishes developing young
until they hatch within the body. Sawfishes are born with a gelatinous
substance around their rostral teeth to protect the mother during birth
(Last and Stevens, 1994; Rainboth, 1996; Compagno and Last, 1999; Raje
and Joshi, 2003; Field et al., 2009). It is thought that most sawfishes
breed every two years and have a gestation period of about four to five
months (Bigelow and Schroeder, 1953; Thorson, 1976a). The number of
young in a litter varies by species, as does the age at sexual
maturity.
Like most chondrichthyes, sawfishes occupy the mid to upper level
of the food web. Smaller sawfishes, including juveniles, may be preyed
upon by larger sharks like the bull shark (Carcharhinus leucas),
estuarine crocodiles (Crocodylus porosus) or alligators (Alligator
mississippiensis). Sawfishes may use their saw as a weapon for defense
against these predators (Brewer et al., 1997; Wueringer et al., 2009).
Previously, seven valid species of sawfish were recognized
worldwide (Compagno, 1999). Per Compagno and Cook (1995) and Compagno
(1999) these are A. cuspidata (Latham 1794), P. microdon Latham 1794,
P. perotteti Muller & Henle 1841, P. pristis (Linnaeus 1758), P.
clavata Garman 1906, P. pectinata (Latham 1794), and P. zijsron
(Bleeker 1851). Since then, the taxonomy, delineation, and
identification of these species have proven problematic (Oijen et al.,
2007; Wiley et al., 2008; Wueringer et al., 2009). Most recently, Faria
et al. (2013) hypothesized that the taxonomic uncertainty occurred due
to several factors: many original species descriptions were
abbreviated, few holotypes are available for examination, reference
material is not available for comparison in museum collections, and it
is difficult to obtain fresh specimens because of the infrequent
captures of all sawfishes. The majority of the confusion regarding
taxonomic classification of Pristidae was related to the species P.
pristis. To resolve these questions regarding the taxonomy of pristids,
Faria et al. (2013) used historical taxonomy, external morphology, and
mitochondrial DNA (mtDNA) sequences (NADH-2 loci) to hypothesize that
the sawfishes comprise five species in two genera: P. pristis, P.
clavata, P. pectinata, P. zijsron, and A. cuspidata. We accept this
proposed taxonomy as the best available science at this time.
Natural History of the Narrow Sawfish (Anoxypristis cuspidata)
Taxonomy and Morphology
The narrow sawfish was first described by Latham in 1794 as P.
cuspidatus. It was later reclassified as Anoxypristis due to
morphological differences from Pristis that include its narrow rostral
saw, which lacks teeth on the first quarter of the saw closest to the
head in adults, and the distinct shape of the lower lobe of the caudal
fin (Compagno et al., 2006a). In juveniles the portion of the rostrum
without teeth is only about one-sixth of the saw length (Wueringer et
al., 2009).
In addition, the narrow sawfish is characterized by dagger-shaped
rostral teeth (Fowler, 1941; Blegvad and Loppenthin, 1944; Compagno and
Last, 1999; Faria et al., 2013). The narrow sawfish also has a second
pair of lateral canals in its rostrum that are not present in other
sawfishes. These canals contain an additional connection to the
ampullae of Lorenzini located on the underside of the rostrum
(Wueringer et al., 2009).
Rostral tooth count varies for this species between 18-22 (Last and
Stevens, 1994), 24-28 (Hussakof, 1912), and 27-32 (Miller, 1974). Total
number of teeth has been found to vary by individual, region, and sex.
Some studies report males having fewer rostral teeth than females, and
others the opposite (Last and Stevens, 1994; Compagno and Last, 1999).
While total rostral tooth count is often inconsistent among individuals
or studies, the number of teeth an individual has is fixed during
development (Wueringer et al., 2009).
The pectoral fins of the narrow sawfish are narrow, short, and
shark-like in shape. The first dorsal fin is located posterior to the
insertion of the pelvic fins (Compagno and Last, 1999). Within the jaw,
there are 94 teeth on the upper jaw and 102 on the lower jaw (Taniuchi
et al., 1991a). The eyes are large and very close to the spiracles.
Coloration is dark grey dorsally and whitish ventrally (Fowler, 1941;
Compagno and Last, 1999).
Narrow sawfish are the only sawfish having tricuspid (three-
pointed) denticles (White and Moy-Thomas, 1941). Because these
denticles first appear on neonate sawfish at 25.6-28 in (65-71 cm)
total length (TL), they are developed post-natally. In general, the
narrow sawfish is considered ``naked'' because denticle coverage in
adults is often sporadic and widely spaced, usually only covering the
rostrum and anterior fin margins, making the skin appear smooth
(Fowler, 1941; Gloerfelt-Tarp and Kailola, 1984; Last and Stevens,
1994; Wueringer et al., 2009). Narrow sawfish also have buccopharyngeal
denticles present in their mouth. This species does not have tubercles
or thorns on their skin (Deynat, 2005).
Habitat Use and Migration
The narrow sawfish is largely euryhaline and moves between
estuarine and marine environments (Gloerfelt-Tarp and Kailola, 1984;
Last, 2002; Compagno, 2002b; Compagno et al., 2006a; Peverell, 2008).
It is generally found in inshore waters in depths of less than 130 ft
(39.6 m) with salinities between 25 and 35 parts per thousand (ppt),
spending most of its time near the substrate or in the water column
over coastal flats (Compagno and Last, 1999; Last, 2002; Peverell,
2005; Peverell, 2008; Wueringer et al., 2009). While Smith (1936)
described it as a possible freshwater species, there are only a few
reports from freshwater (Taniuchi and Shimizu, 1991; Last and Compagno,
2002; Bonfil and Abdallah, 2004; Wueringer et al., 2009). We are not
aware of any fresh or salt water tolerance studies on the species
(Compagno, 2002a; Compagno, 2002b) and conclude its habitat is
euryhaline.
In studies conducted by Peverell (2008), the narrow sawfish in the
Gulf of Carpentaria, Australia undergo an ontogenetic shift in habitat.
Larger individuals were commonly encountered offshore, while smaller
individuals were mostly found in inshore waters. Peverell (2008) also
found females were more likely to be offshore compared to males, at
least during the months of the study (February to May). This suggests
that smaller narrow sawfish use the protection and prey abundance found
in shallow, coastal waters (Dan et al., 1994; Peverell, 2005; Peverell,
2008).
Age and Growth
Two studies have been conducted on age and growth of narrow
sawfish. Field et al. (2009) compared previously-aged vertebrae with
aged rostral teeth and found a direct correlation up to age 6. After
age 6, an individual's age was often underestimated using tooth growth
bands as the teeth become worn over time (Field et al., 2009). Peverell
(2008) then used aged vertebrae to develop more accurate growth curves
for both sexes. While the maximum observed age of narrow sawfish from
vertebrae was 9 years, the theoretical longevity was calculated at 27
years (Peverell, 2008). At an age of one year, saw length is
approximately 4.5 in (11.5 cm). Female narrow sawfish begin to mature
at 8 ft 1 in (246 cm) TL and all are mature at 15 ft 5 in (470 cm) TL;
males are mature at 8 ft (245 cm) TL (Pogonoski et al., 2002; Bonfil
and Abdallah, 2004; Peverell, 2005; 2008). The maximum recorded length
of a narrow sawfish is 15 ft 5 in (4.7 m) TL, with unconfirmed records
of 20 ft (6.1 m) TL (Last and Stevens, 1994; Compagno and Last, 1999;
Pogonoski et al., 2002; Bonfil and Abdallah, 2004; Faria et al., 2013).
Reproduction
The narrow sawfish gives birth to a maximum of 23 pups in the
spring. The total length (TL) of pups at birth is between 17-24 in (43-
61 cm) (Compagno and Last, 1999; Peverell, 2005; 2008). The
reproductive cycle is assumed to be annual, with an average of 12 pups
per litter (Peverell, 2005; D'Anastasi, 2010). The number of pups is
related to female body size, as smaller females produce fewer offspring
than larger females (Compagno and Last, 1999). Preliminary genetic
research suggests that the narrow sawfish may not have multiple fathers
per litter (D'Anastasi, 2010).
Female narrow sawfish captured in August (dry season) in the Gulf
of Carpentaria, Australia, all contained large eggs indicating they
were mature (Peverell, 2005). Mature males were also captured in
similar locations during the same time of year (McDavitt, 2006).
Although sexually mature, mating may not occur until the rainy season
in March-May (Raje and Joshi, 2003).
Age at maturity for narrow sawfish is 2 years for males and 3 years
for females (Peverell, 2008). The intrinsic rate of population increase
(rate of growth of the population) based on life history data from the
exploited population in the Gulf of Carpentaria, Australia, has been
estimated at 0.27 per year (Moreno Iturria, 2012), with a population
doubling time of 2.6 years.
Diet and Feeding
Narrow sawfish feed on small fish and cuttlefish (Compagno and
Last, 1999; Field et al., 2009) and, likely, crustaceans, polychaetes,
and amphipods (Raje and Joshi, 2003).
Population Structure
Genetic and morphological data support the division of the global
species of narrow sawfish into subpopulations (Faria et al., 2013).
Based on gene sequence data, there is a very low level of gene flow
between the northern Indian Ocean (N=2) and west Pacific (N=11)
populations. In a qualitative analysis when data were pooled, four
haplotypes were identified:
northern Indian Ocean; Indonesian; New Guinean-Australian; and a
northern Indian Ocean haplotype from a single specimen that lacked
capture location (Faria et al., 2013). A morphological distinction in
narrow sawfish between the Indian Ocean and western Pacific Ocean
subpopulations occurs in the number of rostral teeth (Faria et al.,
2013). Specimens collected from the Indian Ocean had a higher number of
rostral teeth per side than those collected from the western Pacific.
Field et al. (2009) examined the primary chemical components of
rostral teeth (i.e., oxygen, calcium, and phosphorous) from narrow
sawfish captured throughout Australia in an attempt to separate
subpopulations based on the isotopes of these chemicals. They found
distinctions between regions indicating two separate subpopulations
within the Gulf of Carpentaria Australia: one in the west (Northern
Territory) and one in the east (Queensland). However, we realize that
using isotopes to separate elasmobranch populations is in its infancy
and, coupled with the limited number of samples, it is not yet clear
whether these results agree with the above genetic studies of
population structure. Isotopic signatures indicate the location where
an animal spends most of its time and identifies its major prey
resources, and do not necessarily provide information on reproductive
connectivity between regions. Therefore, we conclude that the best
available information on isotopic signatures does not support
separating narrow sawfish into subpopulations.
Distribution and Abundance
The narrow sawfish is found throughout the eastern and western
portions of the Indian Ocean as well as much of the western Pacific
Ocean. The range once extended from as far west as the Red Sea in Egypt
and Somalia (M. McDavitt pers. comm. to IUCN, 2012) to as far north as
Honshu, Japan, including India, Sri Lanka, and China (Blaber et al.,
1994; Last and Stevens, 1994; Compagno and Last, 1999; Compagno et al.,
2006a; Van Oijen et al., 2007). The species has also been recorded in
rivers in India, Burma, Malaysia, and Thailand (Compagno, 2002b).
While uncertain, the current status of narrow sawfish populations
across its range has declined substantially from historic levels. The
species was previously commonly reported throughout its range but it is
now becoming rare in catches by both commercial and recreational
fishers (Brewer et al., 2006; Compagno et al., 2006a). To evaluate the
current and historic distribution and abundance of the narrow sawfish,
we conducted an extensive search of peer-reviewed publications and
technical reports, newspaper, and magazine articles. The result of that
search is summarized below by major geographic region.
Indian Ocean
The earliest reports of narrow sawfish in the Indian Ocean were
from 1937 and 1938. Two sawfish were captured from the northern Indian
Ocean (no specific location was reported). A third specimen was later
caught in the same area (Blegvad and Loppenthin, 1944).
From areas in the western Indian Ocean around the Arabian Sea,
three rostra were collected in 1938: two near Bushire, Iran, presumably
from the Gulf of Oman, and a third in Jask, Iran, also adjacent to the
Gulf of Oman (Blegvad and Loppenthin, 1944). The most extensive report
was 13 rostra from the Persian Gulf (one of those was from Iran) but it
did not include date information (Faria et al., 2013). Four juveniles
were recorded in Pakistan waters in 1975; two females and two males.
Most records of narrow sawfish in the Indian Ocean are from the Bay
of Bengal. In 1960 and 1961, 118 sawfish, mostly narrow sawfish, were
captured during fishery surveys using gillnets and long lines (James,
1973). There are several additional records of rostra from Bangladesh
in the 1960s (Faria et al., 2013). A narrow sawfish was used for a 1969
parasitological study in Bangladesh but no further information was
recorded (Moravec et al., 2006). Faria et al. (2013) also reported one
specimen from 1976, as well as eleven more records off India, but no
dates were recorded. From 1982-1994, one juvenile female, one juvenile
male, and three rostra were recorded in Pondicherry, India (Deynat,
2005). Two female neonate specimens were recorded in Sri Lanka, and
three juveniles (two males and one female) from Malabar in southwest
India were also reported from 1982-1994 (Deynat, 2005). Between 1981-
2000, in the Bay of Bengal, total elasmobranch landings records are
dominated by rays, but include narrow sawfish (Raje and Joshi, 2003).
Landings of narrow sawfish are currently reported from the Indian
Ocean off India although they are infrequent (K.K. Bineesh pers. comm.
to IUCN, 2012). The last published record of narrow sawfish from the
western edge of the range, in the Straits of Hormuz, was in 1997 (A.
Moore pers. comm. to IUCN, 2012).
Indo-Pacific Ocean (excluding Australia)
There are several accounts of narrow sawfish over time from various
unspecified locations throughout the Indo-Pacific. The first records of
narrow sawfish were for juvenile males in 1852 and 1854 (Faria et al.,
2013). In 1952, two females were captured from Batavia, Semarang,
Indonesia along with a third female without a rostrum (Van Oijen et
al., 2007). Both a female and male were recorded in 1867. Prior to
1879, one male and one female were also recorded from Indonesia and
four rostra were reported from China in 1898 (Faria et al., 2013).
The next reports of narrow sawfish from the Indo-Pacific occurred
in the 1930's. A female was reported in 1931 in Indonesia (no specific
location), and a male in Singapore in 1937 (Blegvad and Loppenthin,
1944). A narrow sawfish was caught in the Gulf of Thailand in March
1937 (Blegvad and Loppenthin, 1944). A single report from Papua-New
Guinea was recorded in 1938 (Faria et al., 2013). In 1945, narrow
sawfish were reported in the Chao Phraya River, Thailand and its
tributaries (Smith, 1945).
Records of narrow sawfish throughout the Indo-Pacific continue to
be scattered and infrequent throughout the 1950's. Faria et al. (2013)
recorded rostra from Papua-New Guinea; two from 1955, one each from
1966, 1980, and 2000. A male was caught in 1989 from the Oriomo River,
Papua-New Guinea (Taniuchi et al., 1991b; Taniuchi and Shimizu, 1991;
Taniuchi, 2002). There are other reports of narrow sawfish from Papua-
New Guinea around the Gulf of Papua and in Bootless Bay from the
1970's, but there are no recent records (Taniuchi et al., 1991b). In a
comprehensive literature search for the period 1923-1996 on the
biodiversity of elasmobranchs in the south China Sea, Compagno (2002a)
found no records of sawfishes. However, fresh dorsal and caudal fins of
narrow sawfish were found during a survey of fish markets from 1996-
1997 in Thailand (Manjaji, 2002b).
There are even fewer records of narrow sawfish from the Indo-
Pacific over the last few decades. The only known specimen in the 21st
century is a single report from New Guinea in 2001 (L. Harrison pers.
comm.).
Australia
Australia may have larger populations of narrow sawfish than any
other area within the species range (Peverell, 2005). The earliest
record of narrow sawfish is from 1926 from Sydney (Pogonoski et al.,
2002). We found no reports of narrow sawfish from Australia from 1926 until the 1990s. Two
narrow sawfish were reported from the Gulf of Carpentaria in 1990
(Blaber et al., 1994). Single specimens were captured in 1991 from the
west coast of Australia (Alexander, 1991), the Gulf of Carpentaria in
1995 (Brewer et al., 1997) and the Arafura Sea in 1999 (Beveridge et
al., 2005). Faria et al. (2013) reported 3 rostra records from private
collections in Australia from 1998-1999, but no other information on
the collection location was reported.
Narrow sawfish have been reported in multiple studies between 2000
and 2011, mostly from northern Australia. In a bycatch reduction device
study conducted in 2001 in the Gulf of Carpentaria, 25 narrow sawfish
were captured in trawling gear (Brewer et al., 2006). A survey of
fisheries data and records identified 74 offshore and 37 inshore
records of narrow sawfish in the Gulf of Carpentaria (Peverell, 2005).
Between April 2004 and April 2005, 16 narrow sawfish were caught in the
Gulf of Carpentaria during a trawl bycatch study; the mean catch rate
was 0.16 sawfish per hour (Dell et al., 2009). Observers on commercial
fishing boats recorded nine captures of narrow sawfish in 2007 within
the Great Barrier Reef World Heritage Area, Queensland, which accounted
for 0.86 percent of the shark and ray catch in the commercial fisheries
(Williams, 2007). Observers in the Northern Territory's Offshore Net
and Line Fishery encountered several narrow sawfish from 2007-2010
(Davies, 2010). Data from the Kimberley, Australia (R. McAuley pers.
comm.to C. Simpfendorfer, 2012), the Northern Territory (Field et al.,
2009), the Gulf of Carpentaria (Peverell, 2005), and parts of the
Queensland east coast (Harry et al., 2011) suggest viable
subpopulations may remain locally, but at significantly lower levels
compared to historic levels.
In summary, it appears the current range of narrow sawfish is
restricted largely to Australia. Narrow sawfish are considered very
rare in many places where evidence is available, including parts of
India (Roy, 2010), Bangladesh (Roy, 2010), Burma (FIRMS, 2007-2012),
Malaysia (including Borneo; Almada-Villela 2002; Manjaji, 2002),
Indonesia (White and Kyne, 2010), Thailand (CITES, 2007; Compagno,
2002a; Vidthayanon, 2002), and Singapore (CITES, 2007). In Australia,
narrow sawfish are primarily located in the northern area. For example,
a bycatch reduction device study conducted in 2001 reported narrow
sawfish in the Gulf of Carpentaria, a similar study conducted off the
eastern coast did not capture a single specimen (Courtney et al.,
2006). The most recent museum record for narrow sawfish in southern
Australia was from New South Wales in the 1970s (Pogonoski et al.,
2002). Data from the Queensland Shark Control Program, conducted along
the east coast of Queensland, from 1969-2003 shows a clear decline in
sawfish catch (although not species-specific) with the complete
disappearance of sawfish in southern regions of Queensland by 1993
(Stevens et al., 2005). Although we cannot rule out underreporting of
narrow sawfish, especially in remote areas of its historic range, we
conclude from the consistent lack of records that narrow sawfish have
been severely depleted in numbers and their range has contracted.
Natural History of Dwarf Sawfish (Pristis clavata)
Taxonomy and Morphology
Due to its small size and geographic location where it was
described, P. clavata is referred to as the dwarf or the Queensland
sawfish. The species was first described by Garman in 1906; however it
has often been confused with the smalltooth sawfish or largetooth
sawfish species complex (Last and Stevens, 1994; Cook et al., 2006;
Morgan et al., 2010a) given the lack of distinct characters. Ishihara
et al. (1991a) provides the most concise review of the physical
characteristics of the dwarf sawfish.
The dwarf sawfish is olive brown in color dorsally with a white
underside. The rostrum of this species is quite short, with 19-23
rostral teeth that are moderately flattened, elongated, and peg-like.
Studies indicate that this species does not display significant
differences in the number of rostral teeth between males (19-23 teeth)
and females (20-23 teeth) (Ishihara et al., 1991a; Thorburn et al.,
2008; Morgan et al., 2010a; Morgan et al., 2011). This species can be
distinguished from largetooth sawfish based on tooth morphology as
described by Thorburn et al. (2007). The rostrum makes up 21-26 percent
of the total length of the dwarf sawfish (Blaber et al., 1989; Grant,
1991; Last and Stevens, 1994; Compagno and Last, 1999; Larson et al.,
2006; Wueringer et al., 2009; Morgan et al., 2011).
Morphologically, the origin of the first dorsal fin is slightly
posterior to the insertion of the pelvic fins, and the second dorsal
fin is smaller than the first. The pectoral fins are small, compared to
other sawfish species, and are ``poorly developed'' (Ishihara et al.,
1991a). There is no lower lobe on the caudal fin. Lateral and low keels
are present along the base of the tail (Compagno and Last, 1999;
Wueringer et al., 2009; Morgan et al., 2010a; Morgan et al., 2011).
Within the mouth are 82-84 tooth rows on the upper jaw. Total vertebrae
number is 225-231. The dwarf sawfish has regularly overlapping
monocuspidate denticles on its skin. As a result, there are no keels or
furrows formed on the skin (Fowler, 1941; Last and Stevens, 1994;
Deynat, 2005).
Habitat Use and Migration
The dwarf sawfish has been found along tropical coasts in marine
and estuarine waters, mostly from northern Australia; it may inhabit
similar habitats in other areas. Dwarf sawfish are reported on mudflats
in water 6 ft 7 in to 9 ft 10 in (2-3 m) deep that is often turbid and
influenced heavily by tides. This species has also been reported in
rivers (Last and Stevens, 1994; Wueringer et al., 2009; Morgan et al.,
2010a) and as commonly occurring in both brackish and freshwater, and
in both marine and estuarine habitats (Rainboth, 1996; Thorburn et al.,
2008).
Juvenile dwarf sawfish may use the estuaries associated with the
Fitzroy River, Australia as nursery habitat for up to three years
(Thorburn et al., 2008). Dwarf sawfish are also known to use the Gulf
of Carpentaria, Australia as nursery area (Gorham, 2006). No adults or
juveniles were found in freshwater areas of the river during the time
of the study. However, physical characteristics such as salinity,
temperature, and turbidity may limit the seasonal movements of the
dwarf sawfish (Blaber et al., 1989).
Age and Growth
While small compared to other sawfishes, the maximum size of dwarf
sawfish has been reported as: 4 ft 11 in (1.5 m) TL (Grant, 1991), 4 ft
7 in (140 cm) TL (Last and Stevens, 1994; Rainboth, 1996; Compagno and
Last, 1999), 10 ft (306 cm) TL (Peverell, 2005), and 11.5 ft (350 cm)
TL (Peverell, 2005). Specimens from western Australia in 2008 indicate
that females reach at least 10 ft 2 in (310 cm) TL (Morgan et al.,
2010a; Morgan et al., 2011).
Thorburn et al. (2008) and Peverell (2008) estimated age and growth
for this species based on the number of vertebral rings and total
length. The average growth estimates for dwarf sawfish are 16.1 in
(41cm) TL in the first year, slowing to 9.4 in (24cm) in the second
year (Peverell 2008). Thorburn et al. (2008) determined that animals
close to 3 ft (90 cm) TL were age 1, those between 3.5 and 4 ft (110 cm
and 120 cm) TL were age 2, and those around 5 ft (160 cm) TL were age
6. Peverell (2008) reported dwarf sawfish between 2 ft 11 in and 3 ft 3 in (90 and
98 cm) TL were age 0, those between 3 ft 7 in and 5 ft 9 in (110-175
cm) TL were considered 1 to 3 years old, and those between 6 ft 7 in
and 8 ft (201-244 cm) TL were considered 4 to 6 years old (Peverell,
2008). Any dwarf sawfish over 9 ft 10 in (300 cm) TL is considered to
be at least 9 years old (Morgan et al., 2010a). The theoretical maximum
age calculated from von Bertalanffy parameters for dwarf sawfish is 94
years (Peverell, 2008).
Reproduction
There is little information available regarding the time or
location of dwarf sawfish mating. It is hypothesized dwarf sawfish move
into estuarine or fresh waters to breed during the wet season (Larson
et al., 2006), however no information on pupping habitat, gestation
period, or litter size has been recorded (Morgan et al., 2010a).
Dwarf sawfish are born between 2 ft 2 in and 2 ft 8 in (65 cm and
81 cm) TL (Morgan et al., 2010a; Morgan et al., 2011). Males become
sexually mature between 9 ft 8 in and 10 ft (295 and 306 cm) TL with
fully calcified claspers, though they may mature at smaller sizes,
around 8 ft 5 in (255-260 cm) TL (Peverell, 2005; Thorburn et al.,
2008; Last and Stevens, 2009; Morgan et al., 2011). All males captured
by Thorburn et al. (2008) less than 7 ft 5 in (226 cm) TL were
immature; two females, both smaller than 3 ft 11 in (120 cm) TL, were
also immature. There is little specific information about sexual
maturation of females; females are considered immature at 6 ft 11 in
(210 cm) TL (Peverell, 2005; Peverell, 2008; Morgan et al., 2010a).
Wueringer et al. (2009) indicates that neither males nor females are
mature before 7 ft 8 in (233 cm) TL.
Intrinsic rates of population increase, based on life history data
from Peverell (2008), has been estimated to be about 0.10 per year
(Moreno Iturria, 2012), with a population doubling time of 7.2 years.
Diet and Feeding
Dwarf sawfish, like other sawfishes, uses its saw to stun small
schooling fishes. They may also use the saw for rooting in the mud and
sand for crustaceans and mollusks (Breder Jr., 1952; Raje and Joshi,
2003; Larson et al., 2006; Last and Stevens, 2009). In Western
Australia, the dwarf sawfish eats shrimp, mullet, herring, and croaker
(Thorburn et al., 2008; Morgan et al., 2010a).
Population Structure
Phillips et al. (2011) conducted a genetic study looking at mtDNA
of dwarf sawfish and found no distinct difference in dwarf sawfish from
the west coast of Australia and those from the Gulf of Carpentaria in
northern Australia. The genetic diversity of this species was moderate
overall; however, dwarf sawfish from the Gulf of Carpentaria may have a
lower genetic diversity than those of the west coast, possibly due to
either a small sample size or a reduction in abundance (Phillips et
al., 2008). Further declines in abundance as well as genetic drift may
result in reduced genetic diversity (Morgan et al., 2010a; Morgan et
al., 2011).
Later, Phillips et al. (2011), using additional samples determined
the populations of the dwarf sawfish are organized matrilineally (from
mother to daughter), indicating the possibility that females are
philopatric (return to their birth place). Genetic analysis of dwarf
sawfish on the northern coast of Australia determined that they were
distinct from those in other areas (Phillips et al., 2011). While the
genetic diversity of this species is considered low to moderate across
Australia, haplotype diversity in the Gulf of Carpentaria was very low
but was greater in the west compared to the east. Low diversity among
and within groups of dwarf sawfish may be detrimental (Phillips et al.,
2011).
Distribution and Abundance
Dwarf sawfish are thought to historically occur in the Indo-
Pacific, western Pacific, and eastern Indian Oceans, with the
population largely occurring in northern Australia (Last and Stevens,
1994; Last and Compagno, 2002; Compagno, 2002a; Compagno, 2002b;
Thorburn et al., 2008; Wueringer et al., 2009; Morgan et al., 2010a).
While dwarf sawfish may have been historically more widespread
throughout the Indo-West Pacific (Compagno and Last 1999, Last and
Stevens, 2009), there are questions regarding records outside of
Australian waters (DSEWPaC, 2011). In an effort to gather more
information on the historic and current range and abundance, we
conducted an extensive search of peer-reviewed publications and
technical reports, newspaper, and magazine articles. A summary of those
findings is presented below by major geographic region.
Indian Ocean
Dwarf sawfish are considered extremely rare in the Indian Ocean and
there are few records indicating its current presence (Last, 2002).
Faria et al. (2013) report dwarf sawfish from the Indian Ocean: a
female from the Reunion Islands, a female from an unidentified location
in the Indian Ocean, and a male from India. There are no reports of
dwarf sawfish from Sri Lanka in more than a decade, although they have
been assumed to occur there (Last, 2002).
Indo-Pacific (excluding Australia)
Dwarf sawfish are considered very rare in Indonesia, with only a
few records (Last, 2002). Faria et al. (2013) compiled most reports of
dwarf sawfish in Indonesia; since the first record in 1894, there has
been two rostral saws in 1910, and 5 other rostra without date or
length information.
Although reported historically, dwarf sawfish have not been
reported from most other areas in the Indo-Pacific in over a decade.
The most recent report of a dwarf sawfish in Thailand was in the Mekong
River Basin, Laos in 1996. No sawfish species, including the dwarf
sawfish, were reported from the South China Sea from 1923-1996
(Compagno, 2002a).
Pacific Ocean
Very few reports of the dwarf sawfish have been recorded in the
western Pacific Ocean. Deynat (2005) reported on two skin samples from
a juvenile female found in Tasmanian waters, and Faria et al. (2013)
reported on two additional specimens but no specifics were provided.
Australia
Australia likely represents the center of the range of dwarf
sawfish. Dwarf sawfish have been reported from Cairns to the east
through the Gulf of Carpentaria in the north and through Kimberley to
the west (Compagno and Last, 1999, Last and Stevens, 2009).
Most records for dwarf sawfish are from the north and northwest
areas of Australia. The earliest record of this species is from 1877
(Faria et al., 2013). A single rostrum from a dwarf sawfish was found
in 1916, but no other information was recorded. In 1946, a number of
dwarf sawfish were reported (Faria et al., 2013).
Most records over the last 30 years have been from north and
northwest Australia. Five female and five male dwarf sawfish (32-55 in;
82-140 cm TL) were captured in 1990 in the Pentecost River using
gillnets (Taniuchi and Shimizu, 1991; Taniuchi, 2002). Between 1994 and
2010, almost 75 tissue samples were taken from live dwarf sawfish or
dried rostra from the Gulf of Carpentaria and the northwest coast of Australia (Phillips et
al., 2011). In 1997, two specimens were collected near the mouth of
Buffalo Creek in Darwin, Northern Territory (Chisholm and Whittington,
2000). In 2005, Naylor et al. (2005) collected one dwarf sawfish from
Darwin, Australia. One dwarf sawfish was captured in 1998 in the upper
reaches of the Keep River estuary (Larson, 1999; Gunn et al., 2010).
One interaction was reported between 2007 and 2010 by observers in the
Northern Territory Offshore Net and Line Fishery (Davies, 2010). A
single specimen from Queensland (eastern Australia) is preserved at the
Harvard Museum of Comparative Zoology (Fowler, 1941).
In a comprehensive survey of the Gulf of Carpentaria from 2001-
2002, Peverell (2005; 2008) indicated dwarf sawfish were concentrated
in the western portion of the Gulf of Carpentaria; twelve males and ten
females were captured. Most individuals caught in the inshore fishery
were immature except for two mature males: 10 ft and 9 ft 8 in (306 cm
and 296 cm) TL (Peverell, 2005; 2008).
In northwestern Australia within specific riverine basins, dwarf
sawfish have been reported in various surveys. Forty-four dwarf sawfish
were captured between October 2002 and July 2004 in the King Sound and
the Robison, May, and Fitzroy Rivers (Thorburn et al., 2008). Between
2001 and 2002, one dwarf sawfish was caught at the mouth of the Fitzroy
River in western Australia (Morgan et al., 2004). Morgan et al. (2011)
acquired 109 rostra from dwarf sawfish from the King Sound area that
were part of museum or personal collections.
In summary, there is some uncertainty in the species identification
of historic records of dwarf sawfish, the intense fishing pressures
within the range has likely caused the dwarf sawfish to become
extirpated from much of the Indo-Pacific region and the species appears
to be extirpated from eastern Australia. An October 2001 study on the
effectiveness of turtle excluder devices in the prawn trawl fishery in
Queensland, Australia, reported no dwarf sawfish (Courtney et al.,
2006). Dwarf sawfish are now considered rare in the Gulf of
Carpentaria. It is likely the Kimberley territory and Pilbara region
(western Australia) may be the last significant remaining areas for
dwarf sawfish (P. Kyne pers. comm. to IUCN, 2012).
Natural History of the Largetooth Sawfish (Pristis pristis)
Taxonomy and Morphology
Many have suggested classification of largetooth sawfish into a
single circumtropical species given common morphological features of
robust rostrum, origin of first dorsal fin anterior to origin of pelvic
fins, and presence of a caudal-fin lower lobe (G[uuml]nther, 1870;
Garman, 1913; Fowler, 1936; Poll, 1951; Dingerkus, 1983; Daget, 1984;
S[eacute]ret and McEachran, 1986; McEachran and Fechhelm, 1998;
Carvalho et al., 2007). The recent analysis by Faria et al. (2013) used
mtDNA and contemporary genetic analysis to argue the previously
classified P. pristis, P. microdon, and P. perotteti should now be
considered one species named P. pristis. After reviewing Faria et al.
(2013) and consulting other sawfish experts we conclude, based on the
best available information, that P. pristis applies to all the
largetooth sawfishes previously identified as P. pristis, P. microdon,
and P. perotteti. The largetooth sawfish has a robust rostrum,
noticeably widening posteriorly (width between the two posterior-most
rostral teeth is 1.7-2 times the width between the second anterior-most
rostral teeth). Rostral teeth number is between 14 and 23 per side with
grooves on the posterior margin. The body is robust with the origin of
the first dorsal-fin anterior to the origin of the pelvic fin; dorsal
fins are high and pointed with the height of the second dorsal fin
greater than the first. The lower lobe of the caudal-fin is small but
well-defined with the lower anterior margin about half as long as the
upper anterior margin (Wallace, 1967; Taniuchi et al., 1991a; Last and
Stevens, 1994; Compagno and Last, 1999; Deynat, 2005; Wueringer et al.,
2009; Morgan et al., 2010a; Morgan et al., 2010b; Morgan et al., 2011).
The largetooth sawfish has buccopharyngeal denticles and regularly
overlapping monocuspidate dermal denticles on its skin. The denticles
are present on both dorsal and ventral portions of the body (Wallace,
1967; Deynat, 2005). Within the mouth, there are between 70 and 72
tooth rows on the upper jaw, and 64-68 tooth rows on the lower jaw. The
number of vertebrae is between 226 and 228 (Morgan et al., 2010a).
Coloration of the largetooth sawfish is a reddish brown dorsally and
dull white ventrally (Fowler, 1941; Wallace, 1967; Compagno et al.,
1989; Taniuchi et al., 1991a; Compagno and Last, 1999; Chidlow, 2007).
Male and female largetooth sawfish differ in the number of rostral
teeth. Using largetooth sawfish teeth collected from Papua New Guinea
and Australia, Ishihara et al. (1991b) found males to have an average
of 21 rostral teeth on the left and 22 on the right; females averaged
19 rostral teeth on both the left and the right side of the rostrum.
Rostrum length can vary between males and females (Wueringer et al.,
2009).
Habitat Use and Migration
Largetooth sawfish are commonly found in coastal, inshore waters
and are considered euryhaline (Compagno et al., 1989; Last and Stevens,
1994; Compagno and Last, 1999; Chisholm and Whittington, 2000; Last,
2002; Compagno, 2002b; Peverell, 2005; Peverell, 2008; Wueringer et
al., 2009), being found in salinities ranging from 0 to 40 ppt
(Thorburn et al., 2007). The species has been found far upriver, often
occupying freshwater lakes and pools; they are associated with
freshwater more than any other sawfish species (Last and Stevens, 1994;
Rainboth, 1996; Peter and Tan, 1997; Compagno and Last, 1999; Larson,
1999). Largetooth sawfish have even been observed in isolated fresh
water billabongs or pools until floodwaters allow them to escape;
juveniles often use these areas for multiple years as deep water
refuges (Gorham, 2006; Thorburn et al., 2007; Wueringer et al., 2009;
Morgan et al., 2010b). Similarly, largetooth sawfish have been found in
Lake Nicaragua in depths up to 400 ft (122 m) and are common in deeper
holes, occupying muddy or sandy bottoms (NMFS, 2010a).
Adults more often utilize marine habitats than juveniles, and are
typically found in waters with salinity at 31 ppt (Wueringer et al.,
2009). Despite the variety of habitats occupied, females have been
found to be highly philopatric as indicated by mtDNA studies, while
males often undergo long movements (Lack et al., 2009; Phillips et al.,
2009; Morgan et al., 2010a; Morgan et al., 2010b; Morgan et al., 2011).
Within the Gulf of Mexico, America, mature largetooth sawfish have
historically moved as far north as Texas (NMFS, 2010a).
The physical characteristics of habitat strongly influence the
movements and areas utilized by largetooth sawfish. Recruitment of
neonate largetooth sawfish was correlated with the rise in water levels
during the wet season in Australia (Whitty et al., 2009). A study of
juvenile largetooth sawfish movements in the Fitzroy River in Australia
found young-of-the-year utilize extremely shallow areas (0-1 ft 7 in or
0-0.49 m) up to 80 percent of the time, mostly to avoid predators
[[Page 33307]]
(Thorburn et al., 2007). Juveniles and adult largetooth sawfish also
utilize rivers (Compagno, 2002b; Gorham, 2006) and can be found in
areas up to 248.5 miles (400 km) upstream (Chidlow, 2007). Activity
space of largetooth sawfish increases with body length (Whitty et al.,
2009).
Age and Growth
There are several age and growth studies for the largetooth
sawfish; results vary due to differences in aging techniques, data
collection, or location. At birth, largetooth sawfish are between 2 ft
6 in and 3 ft (76 and 91 cm) TL, with females being slightly smaller
than males on average (Chidlow, 2007; Morgan et al., 2011). Thorson
(1982) found pups at birth average 2 ft 4.7 in to 2 ft 7.5 in (73-80
cm) TL with a growth rate of 35-40 cm per year (NMFS, 2010a). Juveniles
(age 1 to age at maturity) range in size from 2 ft 6 in to 9 ft (76 to
277 cm) TL (Morgan et al., 2011).
Size at maturity is estimated to be around 9 ft 10 in (300 cm) TL
for both sexes at around age 8 (Lack et al., 2009; Morgan et al.,
2010a; Morgan et al., 2010b; NMFS, 2010; Morgan et al., 2011). Thorson
(1982) estimated age of maturity to be 10 years at 9 ft 10 in (300 cm)
TL in Lake Nicaragua (NMFS, 2010a). Generally, males under 7 ft 7 in
(230 cm) TL and females under 8 ft 10 in (270 cm) TL are considered
immature (Whitty et al., 2009; Wueringer et al., 2009).
The largest recorded length of a largetooth sawfish is 22 ft 11 in
(700 cm) TL (Compagno et al., 1989; Last and Stevens, 1994; Rainboth,
1996; Peter and Tan, 1997; Compagno and Last, 1999; Thorburn and
Morgan, 2005; Compagno et al., 2006b; Chidlow, 2007; NMFS, 2010a). The
largest largetooth sawfish recorded in Kimberley, Queensland measured
21 ft 6 in (656 cm) TL (Morgan et al., 2011). In other areas of
Australia, the largetooth sawfish can reach up to 15 ft (457 cm) and at
least 11 ft 10 in (361 cm) TL (Fowler, 1941; Chidlow, 2007; Gunn et
al., 2010).
Age and growth for largetooth sawfish has been estimated by Tanaka
(1991) who generated a von Bertalanffy growth model for specimens
collected from Papua New Guinea and Australia. For both sexes combined,
the theoretical maximum size was calculated at 11 ft 11 in (363 cm) TL
with a relative growth rate of 0.066 per year. Based on these
calculations, it was determined that largetooth sawfish grow around 7
in (18 cm) in the first year and 4 in (10 cm) by the tenth year.
Thorson (1982a) estimated an early juvenile growth rate of 13-15 in
(35-40 cm) per year and annual adult growth rate of 1 in (4.4 cm) per
year based on largetooth from Lake Nicaragua. Peverell (2008)
calculated a theoretical maximum size of 20 ft 11 in (638 cm) TL with a
relative growth rate of 0.08 per year. The theoretical maximum age
estimated for this species has been calculated to be 80 years (Morgan
et al., 2010a).
Reproduction
Largetooth sawfish are thought to reproduce in freshwater
environments (Compagno and Last, 1999; Last, 2002; Compagno, 2002b;
Martin, 2005; Thorburn and Morgan, 2005; Compagno et al., 2006b) from
May to July (Raje and Joshi, 2003). The number of pups in a largetooth
sawfish litter varies by location, and possibly due to other factors.
One of the earliest reproductive studies on largetooth sawfish by
Thorson (1976a) indicated litter size ranged between 1 to 13 pups, with
an average of 7 pups per cycle (NMFS, 2010a). Thorson (1976a) also
found that both ovaries appeared to be functional, though the left
seemed to be larger and carry more ova (NMFS, 2010a). Length of
gestation for largetooth sawfish is approximately five months, with a
biennial reproductive cycle (NMFS, 2010a). Chidlow (2007) reported
largetooth sawfish had litters with up to 12 pups.
Intrinsic rates of population growth vary tremendously throughout
the species range. Simpfendorfer (2000) estimated that the largetooth
sawfish in Lake Nicaragua had an intrinsic rate of population growth of
0.05 to 0.07 per year, with a population doubling time of 10.3 to 13.6
years. Using data from Australia, rates of population increase were
estimated to be around 0.12 per year (Moreno Iturria, 2012), with a
population doubling time of approximately 5.8 years. Data from the
western Atlantic Ocean indicate an intrinsic rate of increase of 0.03
per year, with a population doubling time of 23.3 years (Moreno
Iturria, 2012).
Diet and Feeding
Largetooth sawfish diet is predominately fish, but varies depending
on study and geographic area. Small fishes including seer fish,
mackerels, ribbon fish, sciaenids, and pomfrets are likely main diet
items of largetooth sawfish in the Indian Ocean (Devadoss, 1978;
Rainboth, 1996; Raje and Joshi, 2003). Small sharks, mollusks, and
crustaceans are also potential prey items (Devadoss, 1978; Rainboth,
1996; Raje and Joshi, 2003). Taniuchi et al., (1991a) found small
fishes and shrimp in the stomachs of juveniles in Lake Murray, Papua
New Guinea, while juvenile sawfish in western Australia had catfish,
cherabin, mollusks, and insect parts in their stomachs (Thorburn et
al., 2007; Whitty et al., 2009; Morgan et al., 2010a). Largetooth
sawfish have also been found to feed on catfish, shrimp, small
crustaceans, croaker, and mollusks (Chidlow, 2007; Thorburn et al.,
2007; Morgan et al., 2010a; Morgan et al., 2010b). Largetooth sawfish
captured off South Africa had bony fish and shellfish as common diet
items (Compagno et al., 1989; Compagno and Last, 1999). In general,
largetooth sawfish subsist on the most abundant small schooling fishes
in the area (NMFS, 2010a).
Population Structure
Genetic analyses based on a 480 base pair sequencing of the mtDNA
gene NADH-2 sequence revealed information indicating largetooth sawfish
subpopulations. Evidence of restricted gene flow has also been found
with largetooth sawfish among these geographic areas: Atlantic and
Indo-West Pacific; Atlantic and eastern Pacific; and Indo-West Pacific
and eastern Pacific. Collectively a total of 19 haplotypes were
identified across largetooth sawfish: one east Pacific haplotype; 12
western Atlantic haplotypes, two eastern Atlantic haplotypes; one
Indian Ocean haplotype, one Vietnamese-New Guinean haplotype, and two
Australian haplotypes (Faria et al., 2013). This fine-scale structuring
of sub-populations by haplotypes was only partially corroborated by the
regional variation in the number of rostral teeth. While the rostral
tooth count differed significantly in largetooth sawfish collected from
the western and eastern Atlantic Ocean, it did not vary significantly
between specimens collected from the Indian Ocean and western Pacific
(Faria et al., 2013). Largetooth sawfish collected from the western
Atlantic specimens had a higher rostral teeth count than those
collected from the eastern Atlantic. Data from separate protein and
genetics studies indicates some evidence of distinction among sub-
populations of largetooth sawfish in the Indo-Pacific. At a broad
scale, Watabe (1991) found that there was limited genetic variability
between samples taken from Australia and Papua New Guinea based on
lactate dehydrogenase (LDH) isozyme patterns. Largetooth sawfish might
be genetically subdivided within the Gulf of Carpentaria, Australia,
with both eastern and western gulf populations (Lack et al., 2009).
Phillips et al. (2011) found that the population of largetooth
sawfish in the Gulf of Carpentaria is different from
[[Page 33308]]
animals on the west coast of Australia (Fitzroy River) based on mtDNA.
Recent data (Phillips, 2012) suggests that matrilineal structuring is
found at relatively small spatial scales within the Gulf of Carpentaria
region (i.e., this region contains more than one maternal
`population'), although the precise location and nature of population
boundaries are unknown. The difference in the genetic structuring using
markers with different modes of inheritance (maternal versus bi-
parental) suggests that largetooth sawfish may have male-biased
dispersal and with females remaining at, or returning to, their birth
place to mate (Phillips et al., 2009, Phillips, 2012). Phillips (2012)
noted that the presence of male gene flow between populations in
Australian waters suggests that a decline of males in one location
could affect the abundance and genetic diversity of assemblages in
other locations.
The genetic diversity for largetooth sawfish throughout Australia
seems to be low to moderate. Genetic diversity was greater in the Gulf
of Carpentaria than in rivers in Australia, also suggesting potential
philopatry (Lack et al., 2009). However, given limited sampling,
additional research is needed to better understand potential population
structure of largetooth sawfish in Australia (Lack et al., 2009;
Phillips et al., 2009; Morgan et al., 2010a; Morgan et al., 2010b).
Distribution and Abundance
Largetooth sawfish have the largest historic range of all
sawfishes. The species historically occurred throughout the Indo-
Pacific near southeast Asia and Australia and throughout the Indian
Ocean to east Africa. Largetooth sawfish have also been noted in the
eastern Pacific Ocean from Mexico to Ecuador (Cook et al., 2005) or
possibly Peru (Chirichigno and Cornejo, 2001). In the Atlantic Ocean,
largetooth sawfish inhabit warm temperate to tropical marine waters
from Brazil to the Gulf of Mexico in the western Atlantic, and Namibia
to Mauritania in the eastern Atlantic (Burgess et al., 2009). Older
literature notes the presence of this species in Zanzibar, Madagascar,
India, and the south-west Pacific (Fowler, 1941; Wallace, 1967;
Taniuchi et al., 2003).
Given the recent taxonomic changes for largetooth sawfish, we
examined all current and historic records of P. microdon, P. perotteti,
and P. pristis for a comprehensive overview on distribution and
abundance. We conducted an extensive search of peer-reviewed
publications and technical reports, newspaper, and magazine articles.
The result of that search is summarized below by major geographic
region.
Indian Ocean
Largetooth sawfish historically occurred throughout the Indian
Ocean; however current records are rare for many areas. The earliest
record of largetooth sawfish was in 1936 from Grand Lac near the Gulf
of Aden, Indian Ocean (Kottelat, 1985). A second record in 1936 is from
Mangoky River, Madagascar (Taniuchi et al., 2003).
Records from the 1960's and 1970's are largely from India and South
Africa. One largetooth sawfish was reported from the confluence of the
Lundi and Sabi Rivers, South Africa in 1960, over 200 miles inland
(Jubb, 1967). Between 1964 and 1966, several largetooth sawfish were
caught in the Zambesi River, South Africa during a general survey of
rays and skates; they have also been recorded in the shark nets off
Durban, South Africa (Wallace, 1967). In 1966, a male (10 ft; 305 cm
TL) was captured in a trawl net in the Gulf of Mannar, Sri Lanka (Gunn
et al., 2010). Largetooth sawfish were commonly caught between 1973 and
1974 in the Bay of Bengal during the wet season (July and September)
but rarely during other times of the year (Devadoss, 1978). Largetooth
sawfish are also recorded in three major rivers that empty into the Bay
of Bengal: the Pennaiyar, Paravanar, and Gadilam (Devadoss, 1978).
Current reports of largetooth sawfish throughout the Indian Ocean
are isolated and rare. While the species could not be confirmed, a
survey of fishing landing sites and interviews with 99 fishers in
Kenya, Nyungi (unpublished report to J. Carlson, NMFS 2007), found 71
reports of sawfishes over the last 40 years. The longest time series of
largetooth sawfish catches is from the protective beach nets off Natal,
South Africa with a yearly average capture rate of 0.2 sawfish per 0.6
mi (1 km) net per year from 1981 to 1990; since then only two specimens
have been caught in the last decade (CITES, 2007). Largetooth sawfish
were reported in Cochin, India by the Central Marine Fisheries Research
Institute in 1994, but no information about location, size or number of
animals is available (Dan et al., 1994). Commercial landings of
elasmobranchs from 1981 to 2000 in the Bay of Bengal were mostly rays
with some largetooth sawfish (Raje and Joshi, 2003). In the Betsiboka
River, Madagascar, four largetooth sawfish were caught in 2001. The
most recent capture of largetooth sawfish (18 ft; 550 cm TL) in India
occurred on January 18, 2011, between Karnataka and Goa
(www.mangalorean.com).
Indo-Pacific Ocean (excluding Australia)
Many islands within the Indo-Pacific region contain suitable
habitat for largetooth sawfish, but few reports are available, perhaps
due to the lack of surveys or data reporting. The earliest records of
largetooth sawfish from the Indo-Pacific are from a compilation study
of elasmobranchs in the waters off Thailand that reports a largetooth
sawfish in the Chao Phraya River and its tributaries in 1945
(Vidthayanon, 2002). In 1955, two largetooth sawfish were captured from
Lake Santani (present day Irian Jaya, Indonesia). Juvenile largetooth
sawfish had also been reported around the same time in a freshwater
river close to Genjem, Indonesia (Boeseman, 1956). In 1956, largetooth
sawfish were recorded in Lake Sentani, New Guinea (Boeseman, 1956;
Thorson et al., 1966). However, in a study by Munro (1967) in the
Laloki River in the southeastern portion of New Guinea, no sawfish were
captured (Berra et al., 1975). From 1967 to 1977, five largetooth
sawfish were captured from the Indragiri River, Sumatra (Taniuchi,
2002). From 1970 to 1971, Berra et al. (1975) collected five largetooth
sawfish from the Laloki River, Papua New Guinea.
More recently, 36 largetooth sawfish were captured in September
1989 in Papua New Guinea (Taniuchi and Shimizu, 1991; Taniuchi, 2002).
In a survey of the Fly River system, Papau New Guinea, 23 individuals
were captured in 1978 (Roberts, 1978; Taniuchi and Shimizu, 1991;
Taniuchi et al., 1991b; Taniuchi, 2002). The presence of largetooth
sawfish in the Mahakam River, Borneo was recorded in 1987 (Christensen,
1992). Three largetooth sawfish rostra were acquired from local fish
markets in Sabah in 1996 (Manjaji, 2002a) and survey indicate
largetooth sawfish are still present in these areas, although locals
have noticed a decline in their abundance (Manjaji, 2002a).
The scarcity of records from Indonesia led to an increased effort
to document species presence (Fowler, 2002). Anecdotal evidence
suggests that sawfishes have not been recorded in Indonesia for more
than 25 years (White and Last, 2010). Largetooth sawfish have not been
recorded in the Mekong River, Laos for decades (Rainboth, 1996). In a
comprehensive study compiled by Compagno (2002a), no sawfishes were
found in the south China Sea between the years of 1923 and 1996. Data
from 200 survey days at fish landing sites in
[[Page 33309]]
eastern Indonesia between 2001 and 2005 recorded over 40,000
elasmobranchs, but only two largetooth sawfish (White and Dharmadi,
2007).
Australian Waters
Australia may have a higher abundance of largetooth sawfish than
other areas within the species' current range (Thorburn and Morgan,
2005; Field et al., 2009). Despite their current abundance levels, we
only identified a few historic records from Australia. The first record
of a largetooth sawfish was in 1945 in the Northern Territory (Stevens
et al., 2005). Faria et al. (2013) obtained a rostrum that was
collected in Australia in 1960.
The most current reports of largetooth sawfish began in the 1980's.
We found many more records of largetooth sawfish in Australia compared
to other countries. A largetooth sawfish was captured from the Keep
River, Australia in 1981 (Compagno and Last, 1999). Blaber et al.
(1990) found that largetooth sawfish were among the top twenty-five
most abundant species in the trawl fisheries of Albatross Bay from 1986
to 1988. Eight individuals were captured in the Leichhardt River in
2008 (Morgan et al., 2010b). In a preliminary survey of the McArthur
River, Northern Territory, Gorham (2006) reported two largetooth
sawfish captured between 2002 and 2006. Surveys (Peverell, 2005; Gill
et al., 2006; Peverell, 2008) in the Gulf of Carpentaria found
largetooth sawfish widely distributed throughout the eastern portion of
the Gulf with most catches occurring near the mouth of many rivers
(Mitchell, Gilbert, Archer, Nassau, Ord, and Staaten).
Juvenile largetooth sawfish in Australia use the Fitzroy River and
other tributaries of the King Sound (Morgan et al., 2004) as nursery
areas while adults are found more often offshore (Morgan et al.,
2010a). Outside of the Fitzroy River and King Sound in western
Australia, the only other areas where juvenile sawfish have been
recently recorded are in Willie Creek and Roebuck Bay (Gill et al.,
2006; Morgan et al., 2011). Nursery areas for largetooth sawfish are
also reported in northern Australia in the Gulf of Carpentaria (Gorham,
2006). Despite the abundance of records from northern Australia, no
sawfish have recently been captured within the Adelaide River,
Australia, and abundance estimates from areas that have higher human
populations may be declining (Taniuchi and Shimizu, 1991; Taniuchi et
al., 1991a; Morgan et al., 2010a). Whitty et al. (2009) found that the
population of juvenile largetooth sawfish in the Fitzroy River have
declined in recent years as catch per unit effort was 56.7 sawfish per
100 hours in 2003, compared to 12.4 in 2009. There were no reported
captures of largetooth sawfish in 2008 from the Roper River system,
which drains into the western Gulf of Carpentaria, Northern Territory
(Dally and Larson, 2008). No adult sawfish were captured in any of the
prawn trawl fisheries in Queensland, Australia during the month of
October 2001 (Courtney et al., 2006).
Outside the northern and western areas of Australia, largetooth
sawfish do occur but reports are less frequent. In southwestern
Australian waters, one female sawfish was captured by a commercial
shark fisherman in February 2003, east of Cape Naturaliste (Chidlow,
2007). Data from the Queensland, Australia Shark Control Program shows
a clear decline in sawfish catch over a 30 year period from the 1960's,
and the complete disappearance of sawfish in southern regions by 1993
(Stevens et al., 2005).
Eastern Pacific
In the eastern Pacific, the historic range of largetooth sawfish
was from Mazatlan, Mexico to Guayaquil, Ecuador (Cook et al., 2005) or
possibly Peru (Chirichigno and Cornejo, 2001). There is very little
information on the population status in this region and few reports of
capture records. The species has been reported in freshwater in the
Tuyra, Culebra, Tilapa, Chucunaque, Bayeno, and Rio Sambu Rivers, and
at the Balboa and Miraflores locks in the Panama Canal, Panama; Rio San
Juan, Colombia; and in the Rio Goascoran, along the border of El
Salvador and Honduras (Fowler, 1936; 1941; Beebe and Tee-Van, 1941;
Bigelow and Schroeder, 1953; Thorson et al., 1966a; Dahl, 1971;
Thorson, 1974; 1976; 1982a; 1982b, 1987; Compagno and Cook, 1995; all
as cited in Cook et al., 2005). The only recent reports of largetooth
sawfish in this area are anecdotal reports from Columbia, Nicaragua,
and Panama (R. Graham pers. comm. to IUCN, 2012).
Western Atlantic Ocean
In the western Atlantic Ocean, largetooth sawfish were widely
distributed throughout the marine and estuarine waters in tropical and
subtropical climates and historically found from Brazil through the
Caribbean, Central America, the Gulf of Mexico, and seasonally into
waters of the U.S. (Burgess et al., 2009). Largetooth sawfish also
occurred in freshwater habitats in Central and South America.
Throughout the Caribbean Sea, the historical presence of the largetooth
sawfish is uncertain and early records might have been misidentified
smalltooth sawfish (G. Burgess pers. comm. to IUCN, 2012).
Historic records of largetooth sawfish in the western north
Atlantic have been previously reported in NMFS (2010a). Sawfish were
documented in Central America in Nicaragua as early as 1529 by a
Spanish chronicler (Gill and Bransford, 1877). This species was also
historically reported in Nicaragua by Meek (1907), Regan (1908), Marden
(1944), Bigelow and Schroeder (1953) and Hagberg (1968). Five
largetooth sawfish were from a survey of Lake Izaba, Guatemala from
1946 to 1947, and sawfishes were reported to be important inland
fisheries (Saunders et al., 1950). The lone largetooth sawfish reported
from Honduras was acquired from that country, but the true origin of
the rostrum and the date of capture could not be confirmed (NMFS,
2010a).
In Atlantic drainages, largetooth sawfish were found in freshwater
at least 833 miles (1,340 km) from the ocean in the Amazon River system
(Manacapuru, Brazil), as well as in Lake Nicaragua and the San Juan
River; the Rio Coco, on the border of Nicaragua and Honduras; Rio
Patuca, Honduras; Lago de Izabal, Rio Motagua, and Rio Dulce,
Guatemala; and the Belize River, Belize. Largetooth sawfish are found
in Mexican streams that flow into the Gulf of Mexico; Las Lagunas Del
Tortuguero, Rio Parismina, Rio Pacuare, and Rio Matina, Costa Rica; and
the Rio San Juan and the Magdalena River, Colombia; (Thorson, 1974;
1982b; Castro-Augiree, 1978 as cited in Thorson, 1982b; Compagno and
Cook, 1995; C. Scharpf and M. McDavitt, pers. comm., as cited in Cook
et al., 2005).
In the U.S., largetooth sawfish were reported in the Gulf of Mexico
mainly along the Texas coast east into Florida waters, though nearly
all records of largetooth sawfish encountered in U.S. waters were
limited to the Texas coast (NMFS, 2010a). Though reported in the U.S.,
it appears that largetooth sawfish were never abundant, with
approximately 39 confirmed records (33 in Texas) from 1910 through
1961.
The Amazon River basin and adjacent waters are traditionally the
most abundant known range of largetooth sawfish in Brazil (Bates 1964;
Marlier 1967; Furneau 1969). Most of the records for which location is
known originated in the state of Amazonas, which encompasses the middle
section of the Amazon River basin along with the confluence of the Rio
Negro and Rio Solimoes Rivers. The other known locations are from the
states of Rio Grande do Norte, Sergipe, Bahia, Espirito Santo, Rio de
Janeiro, and Sao
Paulo, Para, and Maranhao (NMFS, 2010a). Most records of largetooth
sawfish in the Amazon River (Amazonia) predate 1974. The Magdalena
River estuary was the primary source for largetooth sawfish encounters
in Colombia from the 1940's (Miles, 1945), while other records
originated from the Bahia de Cartagena and Isla de Salamanca (both
marine), and Rio Sinu (freshwater) from the 1960's through the 1980's
(Dahl, 1964; 1971; Frank and Rodriguez, 1976; Alvarez and Blanco 1985).
In other areas of South America, there are only single records from
Guyana, French Guiana, and Trinidad from the late 1800's and early
1900's. Of the five records from Suriname, the most recent was 1962.
Though thought to have once been abundant in some areas of Venezuela
(Cervignon 1966a; 1966b), the most recent confirmed records of
largetooth sawfish from that country was in 1962.
Many records in the 1970's and 1980's are largely due to Thorson's
(1982a; 1982b) research on the Lake Nicaragua-Rio San Juan system in
Nicaragua and Costa Rica. Bussing (2002) indicated that this species
was known to inhabit the Rio Tempisque and tributaries of the San Juan
basin in Costa Rica. Following Thorson's (1982a; 1982b) studies,
records of largetooth sawfish in the western North Atlantic decline
considerably. By 1981, Thorson (1982a) was unable to locate a single
live specimen in the original areas he surveyed. There are no known
Nicaraguan records of the largetooth sawfish outside of the Lake
Nicaragua-Rio San Juan-Rio Colorado system (Burgess et al., 2009),
although largetooth sawfish are still captured incidentally by fishers
netting for other species (McDavitt, 2002). Of the known largetooth
sawfish reported from Mexico, most records are prior to 1978, and
Caribbean records are very sparse (NMFS, 2010a). The last record of a
largetooth sawfish in U.S. waters was in 1961 (Burgess et al., 2009).
Most recent records for largetooth sawfish are in isolated areas.
While many reports of largetooth sawfish from Brazil were from the
1980's and 1990's (Lessa, 1986; Martins-Juras et al., 1987; Stride and
Batista, 1992; Menni and Lessa, 1998; and Lessa et al., 1999), recent
records indicate largetooth sawfish primarily in fish markets at the
Amazon-Orinoco estuaries (Charvet-Almeida, 2002; Burgess et al., 2009).
A Lake Nicaraguan fisherman reports he encounters a few sawfish
annually (McDavitt, 2002). Other records are rare for the area. Three
recent occurrences were found in Internet searches, one being a 200 lb.
(90.7 kg) specimen caught recreationally in Costa Rica (Burgess et al.,
2009). Though reported by Thorson et al. (1966a; 1966b) to be common
throughout the area, there are no recent reports of encounters with
sawfishes in Guatemala. Scientists in Columbia have not reported any
sawfish sightings between 1999 and 2009 (Burgess et al., 2009).
Eastern Atlantic Ocean
Historic records indicate that largetooth sawfish were once
relatively common in the coastal estuaries along the west coast of
Africa. Verified records exist from Senegal (1841-1902), Gambia (1885-
1909), Guinea-Bissau (1912), Republic of Guinea (1965), Sierra Leone
(date unknown), Liberia (1927), Cote d'Ivoire (1881-1923), Congo (1951-
1958), Democratic Republic of the Congo (1951-1959), and Angola (1951).
Most records, however, lacked species identification and locality data
and may have been confused taxonomically with other species.
Unpublished notes from a 1950's survey detail 12 largetooth sawfish
from Mauritania, Senegal, Guinea, Cote d'Ivoire, and Nigeria, ranging
in size from 35-275 in (89-700 cm) TL (Burgess et al., 2009).
A more recent status review by Ballouard et al. (2006) reported
that sawfishes, including the largetooth sawfish, were once common from
Mauritania to the Republic of Guinea, but are now rarely captured or
encountered. According to this report, the range of sawfishes has
decreased to the Bissagos Archipelago (Guinea Bissau). The most recent
sawfish encounters outside Guinea Bissau were in the 1990's in
Mauritania, Senegal, Gambia, and the Republic of Guinea. The most
recent documented largetooth sawfish capture was from 2005 in Nord de
Caravela (Guinea Bissau), along with anecdotal accounts from fishers of
captures off of two islands in the same area in 2008 (Burgess et al.,
2009).
In summary, on a global scale, largetooth sawfish appear to have
been severely fragmented throughout their historic range into isolated
populations of low abundance. Largetooth sawfish are now considered
very rare in many places where evidence is available, including parts
of east Africa, India, parts of the Indo-Pacific region, Central and
South America and west Africa. Even within areas like Australia and
Brazil, the species is primarily located in remote areas. Information
from genetic studies indicates that largetooth sawfish display strong
sex-biased dispersal patterns; with females exhibiting patterns of
natal philopatry while males move more broadly between populations
(Phillips et al., 2011). Thus, the opportunity for re-establishment of
these isolated populations is limited because any reduction in female
abundance in one region is not likely to be replenished by migration
from another region (Phillips, 2012).
Natural History of Green Sawfish (Pristis zijsron)
Taxonomy and Morphology
Pristis zijsron (Bleeker 1851) is frequently known as the narrow
snout sawfish or the green sawfish. Synonymous names include P. dubius
(Gloerfelt-Tarp and Kailola, 1984; Van Oijen et al., 2007; Wueringer et
al., 2009). An alternative spelling for this species' scientific name
(P. zysron) is found in older literature, due to either inconsistent
writing or errors in translation or transcription (Van Oijen et al.,
2007).
The green sawfish has a slim saw with 25-32 small, slender rostral
teeth; tooth count may vary geographically (Marichamy, 1969; Last and
Stevens, 1994; Morgan et al., 2010a). Specimens collected along the
west coast of Australia have 24-30 left rostral teeth and 23-30 right
rostral teeth (Morgan et al., 2010a), although other reports are 23-34
(Morgan et al., 2011). There have been no studies to determine sexual
dimorphism from rostral tooth counts for green sawfish. The rostral
teeth are generally denser near the base of the saw than at the apical
part of the saw (Blegvad and Loppenthin, 1944). The total rostrum
length is between 20.6-29.3 percent of the total length of the animal
and may vary based on the number and size of individuals. In general,
green sawfish have a greater rostrum length to total length ratio than
other sawfish species (Morgan et al., 2010a; Morgan et al., 2011).
In terms of body morphology, the origin of the first dorsal fin on
green sawfish is slightly posterior to the origin of pelvic fins. The
lower caudal lobe is not well defined and there is no subterminal notch
(Gloerfelt-Tarp and Kailola, 1984; Compagno et al., 1989; Last and
Stevens, 1994; Compagno and Last, 1999; Bonfil and Abdallah, 2004;
Wueringer et al., 2009; Morgan et al., 2010a; Morgan et al., 2011). The
green sawfish has limited buccopharyngeal denticles and regularly
overlapping monocuspidate dermal denticles on its skin. As a result,
there are no keels or furrows formed on the skin (Deynat, 2005). The
aptly named green sawfish is greenish brown dorsally and white
ventrally. This species might be confused with the dwarf or smalltooth
sawfish due to its similar size and range (Compagno et al., 2006c).
Habitat Use and Migration
The green sawfish mostly utilizes inshore, marine habitats, but it
has been found in freshwater environments (Gloerfelt-Tarp and Kailola,
1984; Compagno et al., 1989; Compagno, 2002b; Stevens et al., 2008;
Wueringer et al., 2009). In the Gilbert and Walsh Rivers of Queensland,
Australia, specimens have been captured as far as 149 miles (240 km)
upriver (Grant, 1991). However, Morgan et al. (2010a; 2011) report
green sawfish do not move into freshwater for any portion of its
lifecycle. Like most sawfishes, the green sawfish prefers muddy bottoms
in estuarine environments (Last, 2002). The maximum depth recorded for
this species is 131 ft (40 m) but it is often found in much shallower
waters, around 16 ft (5 m; Compagno and Last, 1999; Wueringer et al.,
2009). Adults tend to spend more time in offshore waters in Australia,
as indicated by interactions with the offshore Pilbara Fish Trawl
Fishery, while juveniles prefer protected, inshore waters (Morgan et
al., 2010a; Morgan et al., 2011).
Age and Growth
At birth pups are between 2 ft and 2 ft 7 in (61 and 80 cm) TL. At
age 1 green sawfish are generally around 4 ft 3 in (130 cm) TL (Morgan
et al., 2010a). Peverell (2008) found between age 1-5, green sawfish
measure between 4 ft 2 in and 8 ft 5 in (128 and 257 cm) TL, based on
the vertebral analysis of six individuals (Peverell, 2008; Morgan et
al., 2010a; Morgan et al., 2011). A 12 ft 6 in (380 cm) TL green
sawfish was found to be age 8, a 14 ft 4 in (438 cm) TL individual was
found to be age 10, a 14 ft 9 in (449 cm) TL specimen was found to be
age 16, and a 15 ft (482 cm) TL specimen was found to be age 18
(Peverell, 2008; Morgan et al., 2011).
Adult green sawfish often reach 16 ft 5 in (5 m) TL, but may grow
as large as 23 ft (7 m) TL (Compagno et al., 1989; Grant, 1991; Last
and Stevens, 1994; Compagno and Last, 1999; Bonfil and Abdallah, 2004;
Compagno et al., 2006c; Morgan et al., 2010a). The largest green
sawfish collected in Australia was estimated to be 19 ft 8 in (600 cm)
TL based on a rostrum length of 5 ft 5 in (165.5 cm; Morgan et al.,
2010a; Morgan et al., 2011).
Peverell (2008) completed an age and growth study for green sawfish
using vertebral growth bands. Von Bertalanffy growth model parameters
from both sexes combined resulted in estimated maximum theoretical size
of 16 ft (482 cm) TL, relative growth rate of 0.12 per year and
theoretical time at zero length of 1.12 yrs. The theoretical maximum
age for this species is calculated to be 53 years (Peverell, 2008;
Morgan et al., 2010a).
Reproduction
Last and Stevens (2009) reported size at maturity for green sawfish
at 9 ft 10 in (300 cm) TL, corresponding to age 9. In contrast,
Peverell (2008) reported one mature individual of 12 ft 4 in (380 cm)
TL and estimated its age as 9 yrs. Using the growth function from
Peverell (2008) and assuming length of maturity at 118 in (300 cm),
Moreno Iturria (2012) determined maturation is likely to occur at age
5. Demographic models based on life history data from the Gulf of
Carpentaria indicate the generation time is 14.6 years, the intrinsic
rate of population increase is 0.02 per year, and population doubling
time is approximately 28 years (Moreno Iturria, 2012).
Green sawfish give birth to as many as 12 pups during the wet
season (January through July; Last and Stevens, 1994; Peverell, 2008;
Morgan et al., 2010a; Morgan et al., 2011). In Western Australia,
females are known to pup in areas between One Arm Point and Whim Creek,
with limited data for all other areas (Morgan et al., 2010a; Morgan et
al., 2011). The Gulf of Carpentaria, Australia is also a known nursery
area for green sawfish (Gorham, 2006). It is not known where the green
sawfish breed or length of gestation.
Diet and Feeding
Like other sawfish, green sawfish use their rostra to stun small,
schooling fishes, such as mullet, or use it to dig up benthic prey,
including mollusks and crustaceans (Breder Jr., 1952; Rainboth, 1996;
Raje and Joshi, 2003; Compagno et al., 2006c; Last and Stevens, 2009).
One specimen captured in 1967 in the Indian Ocean had jacks and razor
fish (Caranx and Centriscus) species in its stomach (Marichamy, 1969).
In Australia, the diet of this species often includes shrimp, croaker,
salmon, glassfish, grunter, and ponyfish (Morgan et al., 2010a).
Population Structure
Faria et al. (2013) found no global population structure for green
sawfish in their genetic studies. However, geographical variation was
found in the number of rostral teeth per side, suggesting some
population structure may occur. Green sawfish from the Indian Ocean
have a higher number of rostral teeth per side than those from Western
Pacific specimens (Faria et al., 2013).
In Australia, genetic analysis found differences in green sawfish
between the west coast, the east coast, and the Gulf of Carpentaria
(Phillips et al., 2011). Genetic data suggests these populations are
structured matrilineally (from the mother to daughter) but there is no
information on male genet flow at this time. These results may be
indicative of philopatry where adult females return to or remain in the
same area they were born (Morgan et al., 2010a; Morgan et al., 2011;
Phillips et al., 2011). Phillips et al. (2011) also found low levels of
genetic diversity for green sawfish in the Gulf of Carpentaria,
suggesting the population may have undergone a genetic bottleneck.
Distribution and Abundance
The green sawfish historically ranged throughout the Indo-West
Pacific from South Africa northward along the east coast of Africa,
through the Red Sea, Persian Gulf, southern Asia, Indo-Australian
archipelago, and east to Asia as far north as Taiwan and southern China
(Fowler, 1941; Blegvad and L[oslash]ppenthin, 1944; Smith, 1945; Misra,
1969; Compagno et al., 2002a and 2002b; Last and Stevens, 2009).
Historic records indicating species presence are available from India,
southeast Asia, Thailand, Malaysia, Indonesia, New South Wales, and
Australia (Cavanagh et al., 2003; Wueringer et al., 2009; Morgan et
al., 2010a; Morgan et al., 2011). Green sawfish have also been found in
South Africa, the south China Sea, and the Persian Gulf (Fowler, 1941;
Compagno et al., 1989; Grant, 1991; Compagno and Last, 1999; Last,
2002; Compagno, 2002b; Morgan et al., 2010a). To evaluate the current
distribution and abundance of the green sawfish, we conducted an
extensive search of peer-reviewed publications and technical reports,
newspaper, and magazine articles. The results are summarized below by
geographic area.
Indian Ocean
Green sawfish are widely distributed throughout the Indian Ocean
with the first record in 1852 and several green sawfish were described
near the Indian archipelago in the late 1800's (Van Oijen et al.,
2007). Additional historical records include one female specimen
captured in the Red Sea near Dollfus in 1929. In Egypt, two green
sawfish rostra were found in 1938 and an additional rostrum was found
on Henjam Island, Gulf of Oman (Blegvad and Loppenthin, 1994).
Unconfirmed reports of green sawfish are available from the Andaman
and
[[Page 33312]]
Nicobar Islands, India. In 1963, a male was captured at Port Blair,
Gulf of Andaman (James, 1973). A female was captured in 1967 in the
same area (Marichamy, 1969). One green sawfish was captured in the St.
Lucia estuary, South Africa during a survey between 1975 and 1976
(Whitfield, 1999).
Despite historic records, there are few current records of green
sawfish in the Indian Ocean. We presume green sawfish are extirpated in
the Indian Ocean based on the lack of current records.
Indo-Pacific Ocean (Excluding Australia)
The first description of the green sawfish was based on a rostral
saw (Bleeker, 1851) from Bandjarmasin, Borneo (Van Oijen et al., 2007).
A juvenile male was captured in Amboine, Indonesia in 1856 (Deynat,
2005). An isolated saw from the Gulf of Thailand was obtained in 1895
and estimated to be from a green sawfish 4 ft 8 in (143 cm) TL (Deynat,
2005). Eight specimens were sent to the Wistar Institute of Anatomy in
1898 from Baram, British North Borneo (Fowler, 1941).
Many islands within the Indo-Pacific region contain suitable
habitat for sawfish but few records are available, possibly due to the
lack of surveys or data reporting. Before 1995, there were few local
scientific studies on the elasmobranchs, and only two species of
freshwater ray had been recorded in Borneo. As a result, a great effort
to document any unknown species was undertaken by Fowler (2002). Rostra
and records were documented in the study, including several dried
rostra of green sawfish from the Kinabatangan River area in the local
markets of Sabah; no collection specifics were provided. Locals also
indicated that this species could often be found in the Labuk Bay area
(Manjaji, 2002a) and in the country's freshwater systems (Manjaji,
2002b), and reported a decline of sawfish overall.
Elsewhere in the Indo-Pacific region, few records of green sawfish
have been reported. This species is currently considered endangered in
Thailand by Vidthayanon (2002), and Compagno (2002a) reported no
sawfish species from the south China Sea from 1923 through 1996.
Anecdotal evidence suggests that sawfishes have not been recorded in
Indonesia for more than 25 years (White and Last, 2010).
Australia
In Australian waters, records indicate green sawfish abundance is
higher in the north compared to the south. The earliest record obtained
was from the Queensland Museum in 1929 indicating that green sawfish
were found in Moreton Bay, Queensland (Fowler, 1941).
We found a paucity of records for green sawfish during the middle
part of the last century. Reports of green sawfish occur again in the
1980's when two green sawfish were captured from Balgal, Queensland,
Australia in 1985 (Beveridge and Campbell, 2005). One green sawfish was
caught in the southern portion of the Gulf of Carpentaria in late 1990
during a fish fauna survey (Blaber et al., 1994). Alexander (1991)
captured a female green sawfish from the west coast of Australia that
was used for a morphological study. Between 1994 and 2010, almost 50
tissue samples were taken from live green sawfish or dried rostra from
multiple areas around Australia, primarily the Gulf of Carpentaria and
northwest and northeast coasts (Phillips et al., 2011). In 1997, one
green sawfish was found at the mouth of Buffalo Creek near Darwin,
Northern Territory, Australia (Chisholm and Whittington, 2000) and in a
survey from 1999 through 2001 by White and Potter (2004) one green
sawfish was captured in Shark Bay, Queensland. Peverell (2005; 2008)
noted the green sawfish was the least encountered species in a survey
from the Gulf of Carpentaria. In 2008, no green sawfish were captured
from the Roper River system, which drains into the western Gulf of
Carpentaria, Northern Territory, Australia (Dally and Larson, 2008).
Some records have been reported for the east coast of Australia; one
female green sawfish was acoustically tracked for 27 hours in May 2004
(Peverell and Pillans, 2004; Porteous, 2004).
In summary, the limited data makes it difficult to determine the
current range and abundance of green sawfish. However, given the
uniqueness (size and physical characteristics) of the sawfish, we
believe the lack of records in the areas where the species was
historically found likely indicates the species may no longer be
present. In Australian waters, based on our review, all sawfish species
have undergone significant declines. The southern extent of the range
of green sawfishes in Australia has contracted (Harry et al., 2011).
Green sawfish have been reported as far south as Sydney, Australia, but
are rarely found as far south as Townsville (Porteous, 2004). Green
sawfish are currently found primarily along the northern coast of
Australia.
Extensive surveys at fish landing sites throughout Indonesia since
2001 have failed to record the green sawfish (White pers. comm. to
IUCN, 2012). There is some evidence from the Persian Gulf and Red Sea
(e.g., Sudan) of small but extant populations (A. Moore pers. comm. to
IUCN, 2012). However, lack of data from surveys and commercial
fisheries throughout much of the remainder of the range suggests that
the abundance of green sawfish has declined significantly and it is
currently at only a small fraction of its historic abundance.
Natural History of the Non-listed Population(s) of Smalltooth Sawfish
(Pristis pectinata)
Taxonomy and Morphology
The smalltooth sawfish was first described as Pristis pectinatus
(Latham, 1794). The name was changed to the currently valid P.
pectinata to match gender of the genus and species.
The smalltooth sawfish has a thick body with a moderately sized
rostrum. As with many other sawfishes, tooth count may vary by
individual or region. While there is no reported difference in rostral
tooth count between sexes, there have been reports of sexual dimorphism
in tooth shape, with males having broader teeth than females (Wueringer
et al., 2009). Rostral teeth are denser near the apex of the saw than
the base. Most studies report a rostral tooth count of 25 to 29 for
smalltooth sawfish (Wueringer et al., 2009). The saw may constitute up
to one-fourth of the total body length (McEachran and De Carvalho,
2002).
The pectoral fins are broad and long with the origin of the first
dorsal fin over or anterior to the origin of the pelvic fins (Faria et
al., 2013). The lower caudal lobe is not well defined and lacks a
ventral lobe (Wallace, 1967; Gloerfelt-Tarp and Kailola, 1984; Last and
Stevens, 1994; Compagno and Last, 1999; Bonfil and Abdallah, 2004;
Wueringer et al., 2009). This species has between 228 and 232 vertebrae
(Wallace, 1967).
The smalltooth sawfish has buccopharyngeal denticles and regularly
overlapping monocuspidate (single-pointed) dermal denticles on their
skin. As a result, there are no keels or furrows formed on the skin
(Last and Stevens, 1994; Deynat, 2005). The body is an olive grey color
dorsally, with a white ventral surface (Compagno et al., 1989; Last and
Stevens, 1994; Compagno and Last, 1999). This species may be confused
with narrow or green sawfish (Compagno, 2002b).
Habitat Use and Migration
All research on habitat use and migration has been conducted on the
U.S. DPS of smalltooth sawfish. A summary of recent information is found in NMFS (2010b), which indicates
sawfish are generally found in shallow waters with varying salinity
level that are associated with red mangroves. Juvenile sawfish also
appear to have small home ranges and limited movements. Since NMFS
(2010b), Simpfendorfer et al. (2011) reported electivity analysis on
sawfish movements and demonstrated an affinity for salinities between
18 and at least 24 ppt, suggesting movements are likely made, in part,
to remain within this salinity range. Therefore, freshwater flow may
affect the location of individuals within an estuary. Poulakis et al.
(2011) found juvenile smalltooth sawfish had an affinity for water less
than 3 ft (1.0 m) deep, water temperatures greater than 30 degrees
Celsius (86 degrees Fahrenheit), dissolved oxygen greater than 6 mg per
liter, and salinity between 18 and 30 ppt. Greater catch rates for
smalltooth sawfish less than 1 year old were associated with shoreline
habitats with overhanging vegetation such as mangroves. Poulakis et al.
(2012) further determined daily activity space of smalltooth sawfish is
less than 1 mi (0.7 km) of river distance. Hollensead (2012) reported
smalltooth sawfish activity areas ranged in size from 837 square yards
to 240,000 square yards to approximately 3 million square yards (0.0007
to 2.59 km\2\) with average range of movements of 7 ft to 20 ft (2.4 to
6.1 m) per minute. Hollensead (2012) also found no difference in
activity area or range of movement between ebb and flood, or high and
low tide. Activity area decreased and range of movement increased at
night, indicating possible nocturnal foraging. Using a combination of
data from pop-off archival transmitting tags across multiple
institutional programs, movements and habitat use of adult smalltooth
sawfish were determined in southern Florida and the Bahamas (Carlson et
al., in review). All smalltooth sawfish generally remained in coastal
waters at shallow depths (96 percent of their time at depths less than
32 ft; 10 m) and warm water temperatures (22-28 degrees Celsius (71.6-
82.4 degrees Fahrenheit) within the region where they were initially
tagged, travelling an average of 49 mi (80.2 km) from deployment to
pop-off location on an average of 95 days. No smalltooth sawfish tagged
within U.S. or Bahamian waters have been tracked to countries outside
where they were tagged.
Age and Growth
There is no age and growth data for smalltooth sawfish outside of
the U.S. DPS. A summary of age and growth data on the U.S. DPS of
smalltooth sawfish is found in NMFS (2010b) indicates rapid juvenile
growth for smalltooth sawfish for the first 2 years after birth.
Recently, Scharer et al. (2012) counted bands on sectioned vertebrae
from naturally deceased smalltooth sawfish and estimated von
Bertalanffy growth parameters. Theoretical maximum size was estimated
at 14.7 ft (4.48 m), relative growth was 0.219 per year, with
theoretical maximum size at 15.8 years.
Reproduction
Outside U.S. waters, smalltooth sawfish have been recorded breeding
in Richard's Bay and St. Lucia, South Africa (Wallace, 1967; Compagno
et al., 1989; Compagno and Last, 1999). Pupping grounds are usually
inshore, in marine or freshwater, and pupping occurs year around in the
tropics, but in only spring and summer at higher latitudes (Compagno
and Last, 1999). Records of captive breeding have been reported from
the Atlantis Paradise Island Resort Aquarium in Nassau, Bahamas;
copulatory behavior was observed in 2003 and 6 months later the female
aborted the pups for unknown reasons (McDavitt, 2006). In October 2012,
a female sawfish gave birth to five live pups (J. Choromanski, pers.
comm.).
Several studies have examined demography of smalltooth sawfish in
U.S. waters. Moreno Iturria (2012) calculated demographic parameters
for smalltooth sawfish in U.S. waters and estimated intrinsic rates of
increase at 7 percent annually with a population doubling time of 9.7
years. However, preliminary results of a different model by Carlson et
al. (2012) indicates population increase rates may be greater, up to
17.6 percent annually, for the U.S. population of smalltooth sawfish.
It is not clear which of these models is more appropriate for the non-
U.S. populations of smalltooth sawfish.
Diet and Feeding
Smalltooth sawfish often use their rostrum saw in a side-sweeping
motion to stun its prey, which may include small fishes, or dig up
invertebrates from the bottom (Breder Jr., 1952; Compagno et al., 1989;
Rainboth, 1996; McEachran and De Carvalho, 2002; Raje and Joshi, 2003;
Last and Stevens, 2009; Wueringer et al., 2009).
Population Structure
A qualitative examination of genetic (NADH-2) sequences revealed no
geographical structuring of smalltooth sawfish haplotypes (Faria et
al., 2013). However, variation in the number of rostral teeth number
per side was found in specimens from the western and eastern Atlantic
Ocean (Faria et al., 2013).
Distribution and Abundance
Outside U.S. waters, smalltooth sawfish were thought to be
historically found in South Africa, Madagascar, the Red Sea, Arabia,
India, the Philippines, along the coast of west Africa, portions of
South America including Brazil, Ecuador, the Caribbean Sea, the Mexican
Gulf of Mexico, as well as Bermuda (Bigelow and Scheroder, 1953;
Wallace, 1967; Van der Elst, 1981; Compagno et al., 1989; Last and
Stevens, 1994; IUCN, 1996; Compagno and Last, 1999; McEachran and De
Carvalho, 2002; Monte-Luna et al., 2009; Wueringer et al., 2009).
However, reports of smalltooth sawfish from other than the Atlantic
Ocean are likely misidentifications of other sawfish (Faria et al.,
2013). In the eastern Atlantic Ocean, smalltooth sawfish were
historically found along the west coast of Africa from Angola to
Mauritania (Faria et al., 2013). Although smalltooth sawfish were
included in historic faunal lists of species found in the Mediterranean
Sea (Serena, 2005), it is still unclear if smalltooth sawfish occurred
as part of the Mediterranean ichthyofauna or were only seasonal
migrants.
To evaluate the current and historic distribution and abundance of
the smalltooth sawfish outside the U.S. DPS, we conducted an extensive
search of peer-reviewed publications and technical reports, newspaper,
and magazine articles. The result of that search is summarized below by
major geographic region.
Eastern Atlantic Ocean
Smalltooth sawfish were once common in waters off west Africa, but
are now rarely reported or documented in the area. The earliest record
of smalltooth sawfish in Africa was in 1907 from Cameroon: seven
records for five males and two females. Female specimens were recorded
in the Republic of the Congo in 1911 and 1948. Other reports from the
Republic of Congo include a male and two females, but dates were not
recorded. A female specimen from Mauritania was recorded but no date is
given (Faria et al., 2013). A rostra from the Republic of the Congo,
Pointe Noire, Molez was found in 1958 as well as a record of a large
female from Somalia in 1909 (Deynat, 2005; Faria et al., 2013). There
are records of smalltooth sawfish from Senegal as early as 1956 and
another rostral saw was recorded in 1959. Faria et al. (2013) also
reports on four other rostra from Senegal, but no specific information is available.
In the 1970s, records of smalltooth sawfish became limited to more
northern areas of west Africa. One rostral saw from Senegal was
recorded in 1975 (Alexander, 1991). Similarly, one rostral saw was
reported from Gambia in 1977, but information about exact location or
sex of the animal was absent (Faria et al., 2013). Faria et al. (2013)
report a record of smalltooth sawfish in Guinea Bissau in 1983 and a
record of a saw in 1987. For a morphological study, Deynat (2005)
obtained a juvenile female from Port-Etienne, Mauritania, in 1986, and
another from Cacheu, Guinea-Bissau in 1983. Two rostra were reported
from the Republic of Guinea: one in 980 and one in 1988 (Faria et al.,
2013).
In the last 10 years, there has been only one confirmed record of a
smalltooth sawfish outside of U.S. waters in Sierra Leone, west Africa,
in 2003 (M. Diop, pers. comm.). Two other countries have recently
reported sawfish (Guinea Bissau, Africa in 2011, and Mauritania in
2010) but these reports did not specify them as smalltooth sawfish.
Western Atlantic Ocean (Outside U.S. Waters)
Overall, records of smalltooth sawfish in the western Atlantic
Ocean are scarce and show a non-continuous range, potentially due to
misidentification with largetooth sawfish. Faria et al. (2013)
summarized most records of smalltooth sawfish in these areas as
described below. The earliest records are a female smalltooth sawfish
from Haiti in 1831 and a female sawfish from Trinidad and Tobago in
1876. Another early record of two smalltooth sawfish saws is from
Guyana in 1886 and an additional saw was later recorded in 1900. In
Brazil, there is a 1910 report of a female smalltooth sawfish.
In the middle part of the 20th century there are reports of two
female smalltooth sawfish from Mexico in 1926. Rostral saws were found
in Suriname in 1943, 1944 and 1963, but no additional location or
biotic information is known. Similarly, one rostrum was reported from
Costa Rica in 1960, one rostral saw from Trinidad and Tobago in 1944,
and in 1958 and 1960, several whole individuals and one rostrum were
recorded from Guyana. There are also several other undated specimens
recorded from Guyana from this period.
There are other records of smalltooth sawfish's presence in the
western Atlantic Ocean but specific information is lacking. For
example, Faria et al., (2013) reports that four rostral saws came from
Mexico and two from Belize. One female was reported from Venezuela and
two saws from Trinidad and Tobago.
In conclusion, while records are sparse, it is likely the
distribution of smalltooth sawfish in the Atlantic Ocean is patchy and
has been reduced in a pattern similar to largetooth sawfish. Data
suggests only a few viable populations might exist outside the U.S. Due
to better quality of habitat and low urbanization, some areas in the
Caribbean Sea may have a greater number of smalltooth sawfish than
other areas. For example, smalltooth sawfish have been repeatedly
reported along the western coast of Andros Island, Bahamas (R.D. Grubbs
pers. comm., 2010) and The Nature Conservancy noted two smalltooth
sawfish at the northern and southern end of the island in 2006. Fishing
guides commonly encounter smalltooth sawfish around Andros Island while
fishing for bonefish and tarpon (R.D. Grubbs pers. comm., 2010), and
researchers tagged two in 2010 (Carlson et al., in review). In Bimini,
Bahamas, generally one smalltooth sawfish has been caught every two
years as part of shark surveys conducted by the Bimini Biological
Station (D. Chapman pers. comm.). In west Africa, Guinea Bissau
represents the last areas where sawfish can be found (M. Diop pers.
comm. to IUCN, 2012). Anecdotal reports indicate smalltooth sawfish may
also be found in localized areas off Honduras, Belize, and Cuba (R.
Graham pers. comm. to IUCN, 2012).
Species Determinations
We first consider whether or not the narrow sawfish (A. cuspidata),
dwarf sawfish (P. clavata), largetooth sawfish (P. pristis), green
sawfish (P. zijsron), and all non-listed population(s) of smalltooth
sawfish (P. pectinata) meet the definition of ``species'' pursuant to
section 3 of the ESA. Then we consider if any populations meet the DPS
criteria.
Consideration as a ``Species'' Under the Endangered Species Act
Based on the best available scientific and commercial information
described above in the natural history sections for each species, we
have determined that the narrow sawfish (A. cuspidata), dwarf sawfish
(P. clavata), largetooth sawfish (P. pristis), and green sawfish (P.
zijsron) are taxonomically-distinct species and therefore eligible for
listing under the ESA.
Distinct Population Segments
In order to determine if any populations segments of the above
species, and especially the petitioned and currently non-listed
population segment of smalltooth sawfish (P. pectinata), constitutes a
``species'' eligible for listing under the ESA, we used the natural
history information and our joint NMFS- USFWS Policy regarding the
recognition of distinct population segments (DPS) under the ESA (61 FR
4722; February 7, 1996). We examined the three criteria that must be
met for a DPS to be listed under the ESA: (1) The discreteness of the
population segment in relation to the remainder of the species to which
it belongs; (2) the significance of the population segment to the
remainder of the species to which it belongs; and (3) the population
segment's conservation status in relation to the Act's standards for
listing (i.e., is the population segment, when treated as if it were a
species, endangered or threatened?).
A population may be considered discrete, if it satisfies one on the
following conditions: (1) It is markedly separated from other
populations of the same taxon as a consequence of physical,
physiological, ecological, or behavioral factors; or (2) it is
delimited by international governmental boundaries within which
differences of control of exploitation, management of habitat,
conservation status, or regulatory mechanisms exist that are
significant in light of section 4(a)(1)(D) of the ESA.
We looked for information indicating that population segments of
narrow sawfish (A. cuspidata); dwarf sawfish (P. clavata); largetooth
sawfish (P. pristis); green sawfish (P. zijsron) were markedly separate
from other populations. There are few data available to examine
physical, physiological, ecological, or behavioral distinctiveness of
these sawfish. The morphology, ecology, and physiology of a sawfish
likely limits extensive transoceanic movements; however local
migrations are likely and limited movement data exists among larger
individuals (Carlson et al,. in review). Phillips et al. (2011) noted
the presence of matrilineal structuring of narrow sawfish (A.
cuspidata), dwarf sawfish (P. clavata), and green sawfish (P. zijsron),
suggesting the presence of either barriers to dispersal or some aspect
of adult behavior limiting the effective dispersal of at least the
female component of populations. Information on the population
structure of the largetooth sawfish (P. pristis) indicates restricted
gene flow between the Atlantic and Indo-West Pacific; Atlantic and Eastern Pacific; and Indo-
West Pacific and Eastern Pacific (Faria et al., 2013). Fine-scale
structuring of subpopulations was only partially collaborated by the
regional variation in the number of rostral teeth (Faria et al., 2013).
The genetic diversity for largetooth sawfish across Australia seems
to be low to moderate. More genetic diversity was found in the Gulf of
Carpentaria than in specific Australian Rivers, indicative of potential
philopatry (Lack et al., 2009). However, data are limited and more
samples are required to fully realize any population structure of
largetooth sawfish (Lack et al., 2009; Phillips et al., 2009; Morgan et
al., 2010a; Morgan et al., 2010b).
Genetic studies of narrow sawfish have also been completed to
evaluate the population structure of the species. Field et al. (2009)
used genetic samples of narrow sawfish and found distinctions in the
isotopic content of their rostral teeth, indicating differences within
samples from the eastern and western portions of the Gulf of
Carpentaria. The techniques used by Field et al. (2009) are still in
its infancy and it is not clear whether or not these results are
typically concordant with the parallel genetic studies of population
structure. Isotopic signatures provide information on the location
where the animal spends most of its time, and does not necessarily
provide information on the reproductive connectivity between various
regions.
Although some studies report geographic variation in rostral tooth
counts and some matrilineal structuring, we conclude that the best
available information indicates individuals of narrow sawfish (A.
cuspidata), dwarf sawfish (P. clavata), green sawfish (P. zijsron), and
largetooth sawfish (P. pristis), are not markedly separated from the
remainder of the species and therefore are not discrete as defined by
the DPS policy. Largetooth sawfish under their original taxonomic
classification (i.e., 3 separate species) might have geographically
separate populations (e.g., western North Atlantic, eastern Pacific,
and Indo-Pacific Ocean), but we cannot conclude any population meets
the DPS criteria of discreteness given the lack of supporting
biological information. Therefore, we will examine the global status of
narrow sawfish, dwarf sawfish, largetooth sawfish, and green sawfish in
our evaluation for endangered or threatened status.
We previously determined that the U.S. DPS of smalltooth sawfish
was discrete (68 FR 15674; April 1, 2003), as no information was
available to indicate smalltooth sawfish in U.S. waters interact with
those in international waters or other countries. The joint DPS policy
states that the agency may consider a population discrete because it
``is delimited by international governmental boundaries within which
differences in control of exploitation, management of habitat,
conservation status, or regulatory mechanisms exist that are
significant in light of section 4(a)(1)(D) of the Act.'' In 2003, we
concluded that the U.S. population of smalltooth sawfish is effectively
isolated and listed it as endangered along international governmental
boundaries (68 FR 15674; April 1, 2003).
We now evaluate the non-U.S. populations of smalltooth sawfish to
determine if they meet the discreteness criteria of the joint DPS
policy. First, we determine the non-U.S. populations of smalltooth
sawfish are discrete from the U.S. population because they are
delimited by international governmental boundaries within which
differences of control of exploitation, management of habitat,
conservation status, or regulatory mechanisms exist that are
significant in light of section 4(a)(1)(D) of the ESA. Because we have
designated critical habitat for the U.S. DPS population of smalltooth
sawfish, there is a regulatory mechanism for protecting juvenile
smalltooth sawfish and their habitats in the U.S. that does not exist
for the non-U.S. populations of smalltooth sawfish. Movement data from
smalltooth sawfish tagged in U .S. and Bahamian waters also indicate no
movement to countries outside where they were tagged. This information
supports the DPS discreteness criterion of being markedly separate as a
consequence of ecological factors. However, we have no information
indicating genetic differences exist between the smalltooth sawfishes
throughout their range outside U.S. waters or other biological
information that would provide a strong basis for further separating
the non-U.S. smalltooth sawfish population into smaller units. We,
therefore, conclude that the non-U.S. populations of smalltooth sawfish
meet the discreteness criterion of the joint DPS policy and we consider
these populations as a single potential DPS.
After meeting the discreteness criterion in the DPS policy, we then
considered whether the non-U.S. population of smalltooth sawfish meets
the significance criterion. The joint DPS policy gives examples of
potential considerations indicating the population's significance to
the larger taxon. Among these considerations is evidence that the
discrete population segment would result in a significant gap in the
range of the taxon. Smalltooth sawfish are limited in their
distribution outside of the U.S. to west Africa, the Caribbean, Mexico,
and Central and South America. Loss of this group of smalltooth sawfish
would result in a significant gap in the range of this species and
restrict distribution to U.S. waters. Because the loss of smalltooth
sawfish in areas outside the U.S. would result in a significant gap in
the range of the species, we conclude the non-U.S. population of
smalltooth sawfish is significant as defined by the DPS policy. We also
note that no difference in status of the species is found among all
areas.
Based on the above analysis of discreteness and significance, we
conclude that the non-U.S. population of smalltooth sawfish (P.
pectinata) meets the definition of a DPS and is eligible for listing
under the ESA, and hereafter refer to it as the non-U.S. DPS of
smalltooth sawfish.
Extinction Risk
We next consider the risk of extinction for narrow sawfish, dwarf
sawfish, green sawfish, largetooth sawfish, and the non-U.S. DPS of
smalltooth sawfish to determine whether the species are threatened or
endangered per the ESA definition. We used the methods developed by
Wainwright and Kope (1999) to organize and summarize our findings. This
approach has been used in the review of many other species (Pacific
salmonid, Pacific hake, walleye pollock, Pacific cod, Puget Sound
rockfishes, Pacific herring, and black abalone) to summarize the status
of the species according to demographic risk criteria. The methods
developed by Wainwright and Kope (1999) further consider the risk to
small populations based on potential genetic effects or random
demographic effects, and considered habitat capacity to answer
questions about the carrying capacity and whether or not the carrying
capacity can ensure the populations viability. Using these concepts, we
estimated the extinction risk for each of the five species at both
current and anticipated risks expected in the foreseeable future. We
also performed a threats assessment by identifying the severity of
threats that exist now and in the foreseeable future. We defined the
``foreseeable future'' as the timeframe over which threats, or the
species response to those threats, can be reliably predicted to impact
the biological status of the species. We determined that the
foreseeable future is approximately three generation times, calculated
for each of the species based on the demographic calculations of Moreno Iturria (2012): narrow
sawfish, 14 years; dwarf sawfish, 49 years; largetooth sawfish, 48
years; green sawfish, 38 years; and the non-U.S. DPS of smalltooth
sawfish, 30 years. After considering the life history of the each
species, availability of data, and type of threats, we concluded that 3
generations was an appropriate measure to evaluate threats in the
foreseeable future. As a late-maturing species, with slow growth rate
and low productivity, it would take more than one generation for any
conservation management action to be realized and reflected in
population abundance indices. The timeframe of 3 generations is a
widely used scientific indicator of biological status, and has been
applied to decision making models by many other conservation management
organizations, including the American Fisheries Society, the CITES, and
the IUCN.
Wainwright and Kope (1999) used trends in abundance, productivity,
and genetic variability to examine short and long-term trends in
abundance as the primary indicators of risk. Wainwright and Kope (1999)
also considered genetic integrity (introduced genotypes, interactions
with hatchery fish, or anthropogenic selection) and connectivity to
assess genetic diversity and take into account the potential for
genetic exchange. Populations that are more fragmented have less
genetic exchange and therefore less connectivity, which increases the
risk of extinction. Loss of fitness and loss of diversity can occur
from random genetic effects and increase the risk of extinction for a
species. The last factor that Wainwright and Kope (1999) evaluated is
the risks associated with recent events. Changes in harvest rates or
natural events (floods, volcanic eruptions) can pose a risk for species
but may not have been adequately considered by looking at the other
effects above when there is a time-lag in seeing the effect of recent
events. Given the global distribution of these sawfishes, coupled with
limited data on catch rates, we did not include these additional
factors in our extinction risk analysis.
We consider four categories to assess extinction risk of each
sawfish species: (1) Abundance, (2) growth rate/productivity, (3)
genetic integrity which includes the connectivity and genetic diversity
of the species, and (4) spatial structure/connectivity. We determined
extinction risk for each category for both now and in the foreseeable
future using a five level qualitative scale to describe our assessment
of the risk of extinction. At the lowest level, a factor, either alone
or in combination with other factors, is considered ``unlikely'' to
significantly contribute to risk of extinction for a species. The next
lowest level is considered to be a ``low'' risk to contribute to the
extinction risk, but could contribute in combination with other
factors. The next level is considered a ``moderate'' risk of extinction
for the species, but in combination with other factors contributes
significantly to the risk of extinction. A ranking of ``likely'' means
that factor by itself is likely to contribute significantly to the risk
of extinction. Finally, the most threatening factors are considered
``highly likely'' to contributes significantly to the risk of
extinction.
We ranked abundance as likely or highly likely to contribute
significantly to the current and foreseeable risk of extinction for all
sawfishes. It appears the northern coast of Australia supports the
largest remaining groups of dwarf, largetooth, green, and narrow
sawfish in the Pacific and Indian Ocean, with some isolated groups in
the western and central Indo-Pacific region, where the latter three
species occur. Smalltooth sawfish are still being reported outside of
U.S. waters in the Caribbean Sea, but records are few and mostly
insular (e.g., Andros Island) where habitat is available and gillnet
fisheries are not a threat to the species (see below). There are only
four records of largetooth sawfish in the eastern Atlantic Ocean over
the last decade. Similarly, recent largetooth sawfish records in the
western Atlantic are from only the Amazon River basin and the Rio
Colorado-Rio San Juan area in Nicaragua. We considered the current
levels of abundance and realize many areas where sawfish still occur
are subject to commercial and artisanal fisheries and potential habitat
loss, and therefore rank the risk of extinction due to low abundance as
high into the foreseeable future.
Wainright and Kope (1999) stated short- and long-term trends in
abundance are a primary indicator of extinction risk and may be
calculated from a variety of quantitative data such as research
surveys, commercial logbook or observer data, and landings information
when accompanied by effort. Similar to information relative to
abundance, we found that the natural history information indicates an
absence of long-term monitoring data for all five sawfishes. We looked
for inferences about extinctions risk of species based on the trends in
past observations using the presence of a particular species at
specified places and times (e.g., Dulvy et al., 2003; Rivadeneira et
al., 2009). The available museum records, negative scientific survey
results, and anecdotal reports indicate the abundance trend for all
five sawfishes is declining and population sizes are small. Information
available on the species' distribution also indicates the populations
are significantly reduced.
We next considered that sawfish have historically been classified
as having both low reproductive productivity and low recovery
potential. We looked to the demography of smalltooth and largetooth
sawfish from the northwest Atlantic Ocean that was originally
investigated using an age-structured life table (Simpfendorfer, 2000).
Using known estimates of growth, mortality, and reproduction at the
time, Simpfendorfer (2000) determined that intrinsic rates of
population increase ranged from 8-13 percent per year, and population
doubling times were approximately 5 to 8.5 years for both species.
These estimates included assumptions that there was no fishing
mortality, no habitat limitations, no population fragmentation, or
other effects of small population sizes. Simpfendorfer (2006) further
modeled the demography of smalltooth sawfish using a method for
estimating the rebound potential of a population by assuming that
maximum sustainable yield was achieved when the total mortality was
twice that of natural mortality (Au and Smith, 1997). This demographic
model produced intrinsic rates of population increase that were from 2-
7 percent per year for both smalltooth and largetooth sawfish. These
values are similar to those calculated by Smith et al. (2008) using the
same methodology corresponding to elasmobranch species with the lowest
productivity (Smith et al., 2008). Musick et al. (2000) noted that
species with intrinsic rates of increase of less than 10 percent were
particularly vulnerable to rapid population declines and a higher risk
of extinction.
Some recent studies on the life history of sawfish, however,
indicate they are potentially more productive than originally proposed.
Growth rates (von Bertalannfy ``K'') for some species, like narrow
sawfish, approach 0.34 per year (Peverell, 2008). Data from tag-
recapture studies and analysis of vertebral growth bands from
smalltooth sawfish indicates that the first few years after birth
represent the time when growth is most rapid (e.g., Simpfendorfer et
al., 2008; Scharer et al., 2012). Using updated life history
information, Moreno Iturria (2012) calculated intrinsic rates of
increase for these five species of sawfish and determined values
ranging from a low of 0.03 per year for largetooth
sawfish to a high of 0.27 per year for narrow sawfish. Considering this
information, and the inferred declining trend in abundance, we conclude
productivity was a moderate risk for the narrow sawfish but a high risk
for the other four species. We also determined that productivity would
remain a moderate risk for the narrow sawfish and a high risk for the
other four species, in the foreseeable future.
We also combined consideration of the two categories including
genetic diversity, spatial structure, and connectivity of each species
as it relates to the genetic integrity. Population structure and levels
of genetic diversity have recently been assessed for the green sawfish,
dwarf sawfish, and largetooth sawfish across northern Australia using a
portion of the mtDNA control region. Phillips et al. (2011) found
statistically significant genetic structure within species and moderate
genetic diversity among these species. These results suggest that
sawfish may be more vulnerable to local extirpation along certain parts
of their range, especially in areas where the population has been
fragmented and movement between these areas is limited. However, these
results do not necessarily suggest a higher risk of extinction
throughout the entire range of the species. Chapman et al. (2011)
investigated the genetic diversity of the U.S. DPS of smalltooth
sawfish that has declined to between one to five percent of its
abundance in the 1900's, while its core distribution has contracted to
less than 10 percent of its former range (NMFS, 2009). Unexpectedly,
the U.S. DPS of smalltooth sawfish exhibited no genetic bottleneck and
has genetic diversity that is similar to other, less depleted
elasmobranch populations (Chapman et al., 2011). Given that all species
of sawfish have suffered similar abundance declines, we believe this
conclusion should serve as a surrogate for the other sawfish species.
Because the U.S. DPS of smalltooth sawfish has not undergone a genetic
bottleneck, we ranked genetic integrity as a moderate risk for all
sawfish species as it is likely in combination with other factors to
contribute significantly to the risk of extinction. However, we
determined that the risk of extinction due to the lack of connectivity
was high for all five species, primarily because all populations have
undergone severe fragmentation. While genetic results provide optimism
for the remaining populations of sawfish, this does not preclude the
promotion of management actions to enhance connectivity among
populations that have been historically fragmented. We are also
somewhat optimistic that sawfish populations may begin to rebuild in
some areas and the risk of connectivity was determined to decrease for
smalltooth and the narrow sawfish in the foreseeable future, although
by only a small amount.
After reviewing the best available scientific data and the
extinction risk evaluation on the 5 species of sawfishes, we conclude
the risk of extinction for all five species of sawfish is high now and
in the foreseeable future.
Summary of Factors Affecting the Five Species of Sawfishes
Next we consider whether any of the five factors specified in
section 4(a)(1) of the ESA are contributing to the extinction risk of
these five sawfishes.
The Present or Threatened Destruction, Modification, or Curtailment of
its Habitat or Range
We identified habitat destruction, modification, or curtailment of
habitat or range as a potential threat to all five species of sawfishes
and determined this factor is currently, and in the foreseeable future,
contributing significantly to the risk of extinction of these species.
Coastal and Riverine Habitats
Loss of habitat is one of the factors determined to be associated
with the decline of smalltooth sawfish in the U.S. (NMFS, 2009). As
juveniles, sawfishes rely on shallow nearshore environments, primarily
mangrove-fringed estuaries as nurseries (e.g., Wiley and Simpfendorfer,
2010; Norton et al., 2012). Coastal development and urbanization have
caused these habitats to be reduced or removed from many areas
throughout the species' historic and current range. Habitat loss was
identified as one of the most serious threats to the persistence of all
species of sawfish, posing high risks for extinction. It is still
unclear how anthropogenic impacts to habitats affect the recruitment of
juvenile sawfish, and therefore adequate protection of remaining
natural areas is essential. Given the threat from coastal urbanization
coupled with the predicted reduction of mangroves globally (Alongi,
2008), we believe the risk of habitat loss would significantly
contribute to both the decline of sawfish and their reduced viability.
We expect habitat modification throughout the range of these
sawfishes to continue with human population increases. As humans
continue to develop rural areas, habitat for other species, like
sawfish, becomes compromised (Compagno, 2002b). Habitat modification
affects all five species of sawfish, especially those inshore, coastal
habitats near estuaries and marshes (Compagno and Last, 1999; Cavanagh
et al., 2003; Martin, 2005; Chin et al., 2010; NMFS, 2010). Mining and
mangrove deforestation severely alter the coast habitats of estuaries
and wetlands that support sawfish (Vidthayanon, 2002; Polhemus et al.,
2004; Martin, 2005). In addition, riverine systems throughout most of
these species' historical range have been altered or dammed. For
example, the potential expansion of the McArthur River Mine would
permanently realign channels that would in turn affect the number of
pools formed during the wet and dry seasons, many of which are used as
refuge areas for dwarf, green, or largetooth sawfish (Polhemus et al.,
2004; Gorham, 2006).
While the status of habitats across the global range of these
sawfishes is not well known, we expect the continued development and
human population growth to have negative effects on habitat, especially
to nearshore nursery habitats. For example, Ruiz-Luna et al. (2008)
acknowledge that deforestation of mangrove forests in Mexico has
occurred from logging practices, construction of harbors, tourism, and
aquaculture activities. Valiela et al. (2001) reported on mangrove
declines worldwide. They showed that the area of mangrove habitat in
Brazil decreased by almost half (9652 to 5173 square miles) from 1983-
1997, with similar trends in Guinnea-Bissau (1837 to 959 square miles)
from 1953-1995. The areas with the most rapid mangrove declines in the
Americas included Venezuela, Mexico, Panama, the U.S., and Brazil.
Along the western coast of Africa, the largest declines have occurred
in Senegal, Gambia, Sierra Leone, and Guinnea-Bissau. World-wide
mangrove habitat loss was estimated at 35 percent from 1980-2000
(Valiela et al., 2001). These areas where mangroves are known to have
decreased are within both the historic and current ranges of these five
species.
Hydroelectric and Flood Control Dams
Hydroelectric and flood control dams pose a major threat to
freshwater inflow into the euryhaline habitats of sawfishes.
Alterations of flow, physical barriers, and increased water temperature
affect water quality and quantity in the rivers, as well as adjacent
estuaries that are important nursery areas for sawfish. Regulating
water flow affects the environmental cues of monsoonal rains and
increased freshwater flow for pupping (Peverell, 2008; Morgan et al.,
2011). Increases in siltation due to regulated water flow may also affect benthic habitat
or prey abundance for these sawfishes (Compagno, 2002; Polhemus et al.,
2004; Martin, 2005; Thorburn et al., 2007; Chin et al., 2010; Morgan et
al., 2010a).
New dams being proposed to provide additional irrigation to
farmland upstream may affect sawfish habitat. For example, the Gilbert
River, in Queensland, Australia drains into the Gulf of Carpentaria
which is the nursery area for green, dwarf, and largetooth sawfish.
Further modification of the McArthur and Gilbert Rivers, along with
increased commercial fishing in coastal waters, will negatively affect
sawfishes by reducing available habitat while increasing bycatch
mortality (Gorham, 2006).
Water Quality
Largetooth sawfish in particular, and likely the other sawfishes,
have experienced a loss of habitat throughout their range due to the
decline in water quality. Agriculture and logging practices increase
runoff, change salinity, and reduce the flow of water into freshwater
rivers and streams that affects the habitat of the largetooth sawfish
(Polhemus et al., 2004; IUCN Red List, 2006); mining seems to be the
most detrimental activity to water quality. Pollution from industrial
waste, urban and rural sewage, fertilizers and pesticides, and tourist
development all end up in these freshwater systems and eventually the
oceans. Pollution from these operations, as well as cyanide spills
(Papua-New Guinea, 1996), has caused a reduction in the number of
sawfish in these freshwater systems (Vidthayanon, 2002; Polhemus et
al., 2004).
In summary, habitat alterations that potentially affect sawfishes
include commercial and residential development, construction of water
control structures, and modification to freshwater inflows. All
sawfishes are vulnerable to a host of habitat impacts because they use
rivers, estuaries, bays, and the ocean at various times of their life
cycle. Based on our review of current literature, scientific survey and
anecdotal information on the historic and current distribution, we find
that destruction, modification, and curtailment of habitat or ranges is
a factor affecting the status of each species, and we conclude that
this factor is contributing, on its own or in combination with other
factors, to the extinction risk of all five species of sawfishes.
Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
We identified overutilization for commercial, recreational,
scientific, or educational purposes as a potential threat to all five
species of sawfishes and determined that it is currently and in the
foreseeable future contributing significantly to their risk of
extinction.
Commercial Fisheries
Commercial fisheries pose the biggest threat to these sawfishes, as
these species are bycatch from many fisheries. Their unusual morphology
and prominent saw makes sawfishes particularly vulnerable to most types
of fishing gear, most notably any type of net (Anak, 2002; Hart, 2002;
Last, 2002; Pogonoski et al., 2002; Cavanagh et al., 2003; Porteous,
2004; Gorham, 2006; IUCN Red List, 2006; Chidlow, 2007; Field, 2009;
Chin et al., 2010; NMFS, 2010, Morgan et al., 2011). Trawling gear is
of particular concern as it is the most common gear used within the
range and habitat of sawfishes (Compagno and Last, 1999; Taniuchi,
2002; Walden and Nou, 2008). In Thailand, for example, all sawfish fins
obtained and sold to markets are a result of bycatch by otter-board
trawling and gillnet fisheries as there are no directed sawfish
fisheries in the country (Pauly, 1988; Vidthayanon, 2002). The Lake
Nicaragua commercial fishery for largetooth sawfish that collapsed
prior to the 1980's was comprised mostly of gillnet boats (Thorson
1982a), and the commercial small coastal shark fishery in Brazil mainly
utilizes gillnets and some handlines (Charvet-Almeida, 2002). Subadult
and adult smalltooth sawfish have been reported as bycatch in the U.S.
Gulf of Mexico and south Atlantic shrimp trawl fishery (NMFS SEFSC,
2011). However, if proper techniques are used, all sawfish species,
particularly adults, are fairly resilient and can be released alive
from most fishing gear (Lack et al., 2009).
While the occasional live release from commercial fishing gear does
occur, sawfishes are often retained. The meat is generally consumed
locally, but the fins and rostra are of high value and sold in markets
where these products are unregulated (CITES, 2007). In Brazil a
captured sawfish is most likely retained because of the value of their
products, as the rostra, teeth, and fins are valued at upwards of
$1,000 U.S. in foreign markets (NMFS, 2010a). The proportion of
largetooth sawfish in these markets is unknown, although as many as 180
largetooth sawfish saws were annually sold at a single market in
northern Brazil in the early 2000's (McDavitt and Charvet-Almeida,
2004). The Trade Records Analysis of Flora and Fauna in Commerce
(TRAFFIC) organization found that meat, liver oil, fins, and skin are
among the most preferred sawfish products in Asian markets (Anak, 2002;
Vidthayanon, 2002). In the Gulf of Thailand, over 5,291 US tons (4,800
tonnes) of rays were caught annually from 1976-1989; at the same time
over 1,102 US tons (1,000 tonnes) of rays were caught in the Andaman
Sea (Vidthayanon, 2002). It is likely that most of these products were
sold in Asian markets because of the high demand for sawfish products.
Reports of sawfish products in various markets throughout Asia are
often inconsistent and inaccurate despite international rules on take
and possession of sawfish products (Fowler, 2002; Clarke et al., 2008;
Kiessling et al., 2009).
Recreational or commercial fishing gear may be abandoned or lost at
sea. These ``ghost'' nets are an entanglement hazard for sawfishes and
have become an increasing problem in the Gulf of Carpentaria where over
5,500 ``ghost nets'' were removed in 2009. Sawfish captures are
expected to occur in regions where no quantitative information about
``ghost nets'' exists (Gunn et al., 2010).
Misidentification, general species-composition grouping, and
failure to record information are all concerns for reporting sawfish
captures in direct or indirect commercial fisheries (Stobutzki et al.,
2002b). With little enforcement of regional and international laws, the
practice of landing sawfishes may continue (NMFS, 2010a). All sawfish
populations have been declining worldwide, partly due to the negative
effects of commercial fishing (Stevens et al., 2000; Peverell, 2008).
Recreational Fisheries
Sawfish are bycatch of many recreational fisheries throughout their
range, even in areas where they are protected, including many
Australian rivers (Walden and Nou, 2008; Field et al., 2009). Peverell
(2008) reports that some sawfish are a target sport fish for
recreational fishermen in the Gulf of Carpentaria, Queensland. Historic
information from the U.S. indicates that recreational hook and line
fishers in Texas sometimes target large sharks as trophy fish but may
capture sawfish (Burgess et al., 2009). Elsewhere in the U.S., the
abundance of sawfishes is low and likely never high enough for
recreational fishers to encounter sawfish, much less target it (NMFS,
2010a). With the increase in human population along the coast, recreational fishing has the potential to
put additional pressure on sawfish species that utilize coastal
habitats (Walden and Nou, 2008).
Indigenous Take
Due to the large populations of various indigenous people
throughout the range of these five species, and the lack of data on the
animals they harvest, the number of sawfish taken by local peoples is
unknown. Elasmobranchs are caught for consumption throughout the Indo-
Pacific. In some areas the meat and fins of these animals is of high
market value and are sold rather than consumed. Due to this unregulated
consumption, removal of elasmobranchs, which includes sawfishes, is a
serious threat (Compagno and Last, 1999; Pogonoski et al., 2002;
Vidthayanon, 2002; Thorburn et al., 2007; Peverell, 2008; Morgan et
al., 2010a).
Some studies have been conducted on the use and value of
elasmobranch parts to various indigenous groups, particularly those in
eastern Sabah, Indonesia. One study (Almada-Villela, 2002) found the
majority of natives from Pulau Tetabuan and Pulau Mabul only take what
is necessary for subsistence. Sawfish rostra are also valued and kept
as decoration or given as gifts at the expense of the animal (Almada-
Villela, 2002; McDavitt et al., 1996; Vidthayanon, 2002).
Protective Coastal Nets
The use of protective gillnets to prevent shark attacks on humans
is great in some areas but can have a negative impact due to bycatch.
Sawfishes are highly susceptible to nets because of their saws that are
easily tangled in the nets. In Africa, the first protective gillnets
lined the southeast tip of the continent's coast as early as 1952. By
1990, over 44 km of nets lined the area between Richards Bay and Mzamba
(Dudley and Cliff, 1993). In these nets specifically, about 350 sharks
and rays were captured between 1981 and 1990. A high percentage of
entangled sawfish are released alive because of their ability to
breathe while motionless. Dudley and Cliff (1993) reported 100 percent
and 67 percent of largetooth and smalltooth sawfish caught during that
time were released alive. However, subsequent mortality post-release
due to stress or injury from the process is unknown and potentially
detrimental given other fishing pressures (Dudley and Cliff, 1993).
Scientific and Educational Uses
Because of their unique morphology, sawfishes are in high demand by
aquariums throughout the world for display (McDavitt et al., 1996).
Removal of these animals from their natural habitats has caused some
concern for these sawfish species and their ecosystems. The animals
removed from the wild could be adult females and would not available
for reproduction (Anak, 2002; Harsan and Petrescu-Mag, 2008). No
information is available on the level of mortality that occurs during
the capture and transporting of live sawfish to aquaria.
Worldwide, we are not aware of any narrow sawfish in captivity
(Peverell, 2005; 2008). We are aware of two dwarf sawfish held in
captivity in Japan (McDavitt, 2006). Largetooth sawfish are the most
common sawfish species in captivity (NMFS, 2010a). Juvenile largetooth
are most often caught for the aquaria trade, measuring less than 3.5 ft
(1 m) TL on average (Peter and Tan, 1997). We are aware of over 45
individual largetooth sawfish in captivity globally.
Globally, scientists are collecting information on sawfish biology.
Research efforts began in 2003, on the U.S. DPS population of
smalltooth sawfish and no negative impacts have been found due to that
research.
While no quantitative data on fishery impacts are available, we
conclude that given the susceptibility of sawfish to entanglement in
predominant fishing gear (nets) throughout their range, that sawfishes
are likely captured as incidental take as we are not aware of any
fisheries specifically targeting sawfishes. This impact from fisheries
is the most likely cause of the range contraction and presumed low
number in many areas of their former range. There are few data
available describing the trade of sawfish parts, however we are aware
sawfish parts are often sold on Internet sites such as eBay. The use of
sawfish teeth as cockfighting spurs and the sale of meat and fins for
consumption continue. Therefore we conclude the overutilization for
commercial and recreational purposes, alone or in combination with
other factors as discussed herein, is contributing significantly to the
risk of extinction of the narrow, dwarf, largetooth, green, and the
non-U.S. DPS of smalltooth sawfish.
Disease and Predation
We determine disease and predation are not potential threats to any
of the five species of sawfish and that it is unlikely that this
factor, on its own or in combination with other factors is, currently
or in the foreseeable future contributing significantly to their risk
of extinction.
Although sympatric with other sawfishes and large sharks, we are
not aware of any studies or information documenting interspecific
competition in terms of either habitat or prey (NMFS, 2010a). Thorson
(1971) speculated that the Lake Nicaragua bull shark population may
compete with the sawfishes, as both were quite prevalent, but he
offered no additional data. Sawfishes have been documented within the
stomach of a dolphin near Bermuda (Bigelow and Schroeder, 1953; Monte-
Luna et al., 2009), in the stomach of a bull shark in Australia
(Thorburn et al., 2004), and a juvenile smalltooth sawfish was captured
in the U.S. with fresh bite marks from what appeared to be a bull shark
(T. Wiley-Lescher, pers. comm.). The International Union for
Conservation of Nature (IUCN) Red List states that crocodiles prey on
sawfishes (Cook, S.F. & Compagno, L.J.V. 2005).
Scientific data does not exist on diseases that may affect
sawfishes, but there are reports of a smalltooth sawfish found dead
during a red tide event on the west coast of Florida (International
Sawfish Encounter Database, 2009). There is no evidence that unusual
levels of disease or predation on their own, or in combination with
other factors, pose an extinction risk to any of these sawfishes.
Inadequacy of Existing Regulatory Mechanisms
We identified inadequacy of existing regulatory mechanisms as a
potential threat to each of the five species of sawfish. We determined
that this factor alone, or in combination with other factors, is
currently, and in the foreseeable future, contributing significantly to
their risk of extinction.
While the use of turtle exclusion devices (TEDs) in the nets of
trawl fisheries to conserve sea turtles occurs throughout the range of
sawfishes, TEDs are not efficient in directing sawfish out of nets
because sawfish rostra get entangled (Stobutzki et al., 2002a; Brewer
et al., 2006) prior to reaching the TED. TEDs are often used when
trawling occurs along the sea bottom or at depths of 49 ft to 131 ft
(15 to 40 m), both areas where sawfish are likely to be found
(Stobutzki et al., 2002a). Most sawfishes show no difference in
recovery after going through a trawl net, regardless of the presence or
absence of a TED (Griffiths, 2006). Stobutzki et al. (2002a) found that
large females are more likely to survive after passing through a
trawling net compared to smaller males.
[[Page 33320]]
Only narrow sawfish were found to benefit from the presence of TEDs in
nets as 73.3 percent escaped (Brewer et al., 2006; Griffiths, 2006). In
general, TEDs tend to have negligible or a negative impact on sawfish
that get captured by trawling nets (Stobutzki et al., 2002a; Griffiths,
2006), but they do provide an escape route if the animal does not get
entangled.
While the international organizations including the Trade Records
Analysis of Flora and Fauna in Commerce (TRAFFIC), the Food and
Agricultural Organization (FAO), the International Council for the
Exploration of the Sea (ICES), and the International Commission for the
Conservation of Atlantic Tuna (ICCAT) work to develop global networks
to monitor wildlife trade, there is no consistent reporting of the
trade in elasmobranchs (Clarke et al., 2008; Lack and Sant, 2011)
perhaps due to their lower commercial value compared to bony fish
(Holmes et al., 2009). Data reporting is often inconsistent among these
groups, customs agencies and national fisheries (Anak, 2002). Reports
are often vague and include general descriptions like ``shark fin'' or
``ray,'' lending practically no information of trading rates of
specific products (Lack and Sant, 2011). Other countries in the Indo-
Pacific do not report bycatch statistics or elasmobranchs taken
illegally (Holmes et al., 2009). In order for effective management
plans to be implemented in fin markets and for sawfish product trade,
data need to be consistent.
Many countries in the Indo-Pacific and the Middle East do not have
formal legislation for management or national protection of the sawfish
that may occur in their waters. Presently, Thailand has no protective
legislation for any elasmobranch in the country, only some regulated
fisheries (Vidthayanon, 2002). Thailand recently (1995) banned export
of marine species for aquaria (Vidthayanon, 2002). Despite efforts by
the International Plan of Action for the Conservation and Management of
Sharks (IPOA Shark Plan) requiring all Gulf of Oman countries to have a
shark conservation plan by 2001, none have been developed as of 2010.
Iran has no regulations regarding fin removal, but they do limit the
shark fishing season in the Gulf of Oman (Moore, 2011). The countries
in Africa face similar circumstances as enforcement for sawfish
protection is unknown (NMFS, 2010a). Those countries that do have
protective legislation are often taken advantage of by foreign vessels
because no punishment results. In one study, DNA barcoding was used to
identify fins from the green sawfish confiscated from foreign boats
illegally fishing in northern Australian waters (Holmes, 2009).
While it appears that several organizations are trying to regulate
and manage sawfish, many have proven to be inadequate. Illegal
exploitation by foreign fishers often occurs when regulations exist but
are not enforced (Kiessling et al., 2009). Preventative measures on
existing fishing mechanisms to avoid sawfish catch, international
monitoring of trade and governmental influence on fisheries are not
presently sufficient to protect sawfishes. Specific regulation and
monitoring of sawfishes by country would provide better protection
(Vidthayanon, 2002; Walden and Nou, 2008). Therefore we conclude the
inadequacy of existing regulatory mechanisms has and continues to
significantly contribute to the risk of extinction of the narrow,
dwarf, largetooth, green, and the non-U.S. DPS of smalltooth sawfish.
Other Natural or Manmade Factors Affecting its Continued Existence
We do not have information to determine that other natural or
manmade factors are potential threats to any of the five species of
sawfishes and conclude it is unlikely that this factor, on its own or
in combination with other factors, is currently or in the foreseeable
future contributing significantly to the risk of extinction.
An increase in global sea-surface temperature and sea level may
already be influencing sawfish populations (Clark, 2006; Walden and
Nou, 2008; Chin et al., 2010). Fish assemblages are likely to change
their distribution and could affect the prey base for sawfishes.
Estuaries, including sawfish pupping grounds, may be affected as
climate change changes patterns in freshwater flow due to rainfall and
droughts. Skewed salinities in these areas or extreme tide levels might
discourage adults from making up-river migrations (Clark, 2006).
Saltwater marsh grass and mangrove areas play important roles in
sawfish habitat as well (Simpfendorfer et al., 2010); any disruption to
these areas may affect sawfish populations. While many scientists can
agree on the presence of climate change, few can agree on the effects
that climate change will have on sawfish and their environments
specifically (Clark, 2006; Chin et al., 2010).
Red tide is the common name for a harmful algal bloom (HAB) of
marine algae (Karenia brevis) that can make the ocean appear red or
brown. Karenia brevis is one of the first species ever reported to have
caused a HAB and is principally distributed throughout the Gulf of
Mexico, with occasional red tides in the mid- and south-Atlantic U.S.
Karenia brevis naturally produces a brevetoxin that is absorbed
directly across the gill membranes of fish or through ingestion of
algal cells. While many HAB species are nontoxic to humans or small
mammals, they can have significant effects on aquatic organisms. Fish
mortalities associated with K. brevis events are very common and
widespread. The mortalities affect hundreds of species during various
stages of development. Red tide toxins can cause intoxication in fish,
which may include violent twisting and corkscrew swimming, defecation
and regurgitation, pectoral fin paralysis, caudal fin curvature, loss
of equilibrium, quiescence, vasodilation, and convulsions, culminating
in death. However, it is known that fish can die at lower cell
concentrations and can also apparently survive in much higher
concentrations. In some instances, mortality from red tide is not acute
but may occur over a period of days or weeks of exposure to subacute
toxin concentrations. There is no specific information on red tide
effects to sawfish, but a report exists of a smalltooth sawfish that
was found dead along the west coast of Florida, during a red tide event
(National Sawfish Encounter Database, 2009). Therefore, we conclude red
tide can affect all sawfish species (NMFS, 2010a).
Sawfishes have slow growth rates, late maturity, a long life span,
and low fecundity rates which make them K-selected animals. K-selected
animals can compete successfully in predictable or stable environments.
K-selected characteristics do not enable them to respond rapidly to
additional sources of mortality, such as overexploitation and habitat
degradation. Collectively these other natural or manmade factors may be
affecting the continued existence of the narrow, dwarf, largetooth,
green, and the non-U.S. DPS of smalltooth sawfish. However, we are
uncertain on the importance of these threats and additional studies are
needed to determine the importance of other manmade and natural factors
to the long-term survival of all five species of sawfishes.
Overall Risk Summary
After considering the extinction risks for each of the five species
of sawfish, we have determined the narrow, dwarf, largetooth, green,
and the non-U.S. DPS of smalltooth sawfish are in danger of extinction
throughout all of their ranges due to (1) Present or threatened
destruction, modification or curtailment
of habitat, (2) overutilization for commercial, recreational,
scientific, or educational purposed, and (3) inadequacy of existing
regulatory mechanisms.
Protective Efforts
Section 4(b)(1)(A) of the ESA requires the Secretary, when making a
listing determination for a species, to take into consideration those
efforts, if any, being made by any State or foreign nation to protect
the species. In judging the efficacy of not yet implemented efforts, or
those existing protective efforts that are not yet fully effective, we
rely on the Services' joint ``Policy for Evaluation of Conservation
Efforts When Making Listing Decisions'' (``PECE''; 68 FR 15100; March
28, 2003). The PECE policy is designed to ensure consistent and
adequate evaluation on whether any conservation efforts that have been
recently adopted or implemented, but not yet proven to be successful,
will result in recovering the species to the point at which listing is
not warranted or contribute to forming the basis for listing a species
as threatened rather than endangered. The PECE policy is expected to
facilitate the development of conservation efforts by states and other
entities that sufficiently improve a species' status so as to make
listing the species as threatened or endangered unnecessary.
The PECE policy establishes two basic criteria to use in evaluating
efforts identified in conservations plans, conservation agreements,
management plans or similar documents: (1) the certainty that the
conservation efforts will be implemented; and (2) the certainty that
the efforts will be effective. We evaluated conservation efforts to
protect and recover sawfish that are either underway but not yet fully
implemented, or are only planned.
All sawfishes in the family Pristidae were listed on Appendix 1 of
the Convention on International Trade in Endangered Species of Wild
Fauna and Flora (CITES) at the 14th Conference of the Parties meeting
in 2007. An Appendix I listing bans all commercial trade in parts or
derivatives of sawfish with trade in specimens of these species
permitted only in exceptional circumstances (e.g., for research
purposes). An annotation to the Appendix I listing allows the
largetooth sawfish P. microdon (herein P. pristis) to be treated as
Appendix II ``for the exclusive purpose of allowing international trade
in live animals to appropriate and acceptable aquaria for primarily
conservation purposes.'' The annotation was accepted on the basis that
Australian populations of P. microdon are robust relative to other
populations in the species' range; and that the capture of individuals
for aquaria is not likely to be detrimental to the population. At the
CITES 16th Annual Conference of the Parties (COP) in March of 2013
Australia's proposal to transfer P. microdon from Appendix II to
Appendix I was adopted. While the recent banning of all trade of
largetooth sawfish has the potential to reduce the number of live
animals removed for aquaria trade, the potential effect of this effort
is unknown, but not likely to significantly affect the species outside
of the limited area where it had been harvested for this trade. Because
trade is not a current threat placing the five species of sawfishes at
risk of extinction, moving the largetooth sawfish from CITES Appendix
II to Appendix I to further restrict trade cannot be considered as an
effective measure in reducing the current extinction risk.
Proposed Determination
Section 4(b)(1) of the ESA requires that we make listing
determinations based solely on the best scientific and commercial data
available after conducting a review of the status of the species and
taking into account those efforts, if any, being made by any state or
foreign nation, or political subdivisions thereof, to protect and
conserve the species. We have reviewed the best available scientific
and commercial information including the petition, and the information
in the review of the status of the five species of sawfishes, and we
have consulted with species experts. We are responsible for determining
whether narrow sawfish (A. cuspidata), dwarf sawfish (P. clavata),
largetooth sawfish (P. pristis), green sawfish (P. zijsron), and all
non-U.S. DPS of smalltooth sawfish (P. pectinata) are threatened or
endangered under the ESA (16 U.S.C. 1531 et seq.). Accordingly, we have
followed a stepwise approach as outlined above in making this listing
determination for these five species of sawfish. We have determined
that narrow sawfish (A. cuspidata); dwarf sawfish (P. clavata);
largetooth sawfish (P. pristis); green sawfish (P. zijsron); and all
non-U.S. DPS of smalltooth sawfish (P. pectinata) constitute species as
defined by the ESA.
Based on the information presented, we find that all five species
of sawfishes are in danger of extinction throughout all of their
ranges. We assessed the ESA section 4(a)(1) factors and conclude the
narrow, dwarf, largetooth, green, and the non-U.S. DPS of smalltooth
sawfish face ongoing threats from habitat alteration, overutilization
for commercial and recreational purposes, and the inadequacy of
existing regulatory mechanisms throughout their ranges. All of the
threats attributed to the species decline are ongoing except the
fishery in Lake Nicaragua that collapsed, presumably with the
largetooth sawfish population. After considering efforts being made to
protect these sawfishes, we could not conclude the proposed
conservation efforts would alter the extinction risk for any of these
five sawfishes.
Effects of Listing
Conservation measures provided for species listed as endangered or
threatened under the ESA include recovery actions (16 U.S.C. 1533(f)),
concurrent designation of critical habitat if prudent and determinable
(16 U.S.C. 1533(a)(3)(A)); Federal agency requirements to consult with
NMFS and to ensure its actions do not jeopardize the species or result
in adverse modification or destruction of critical habitat should it be
designated (16 U.S.C. 1536); and prohibitions on taking (16 U.S.C.
1538). Recognition of the species' plight through listing promotes
conservation actions by Federal and state agencies, foreign entities,
private groups, and individuals. Should the proposed listing be made
final, recovery plans may be developed, unless they would not promote
the conservation of the species.
Identifying Section 7 Consultation Requirements
Section 7(a)(2) (16 U.S.C. 1536(a)(2)) of the ESA and NMFS/USFWS
regulations require Federal agencies to consult with us to ensure that
activities authorized, funded, or carried out are not likely to
jeopardize the continued existence of listed species or destroy or
adversely modify critical habitat. Section 7(a)(2) (16 U.S.C.
1536(a)(2)) of the ESA and NMFS/USFWS regulations also require Federal
agencies to confer with us on actions likely to jeopardize the
continued existence of species proposed for listing, or that result in
the destruction or adverse modification of proposed critical habitat.
It is possible, but highly unlikely, that the listing of the five
species of sawfish under the ESA may create a minor increase in the
number of section 7 consultations for high seas activities.
Critical Habitat
Critical habitat is defined in section 3 of the ESA (16 U.S.C.
1532(5)) as: (1) the specific areas within the geographical area
occupied by a species, at the time it is listed in accordance with the
ESA,
[[Page 33322]]
on which are found those physical or biological features (a) essential
to the conservation of the species and (b) that may require special
management considerations or protection; and (2) specific areas outside
the geographical area occupied by a species at the time it is listed
upon a determination that such areas are essential for the conservation
of the species. ``Conservation'' means the use of all methods and
procedures needed to bring the species to the point at which listing
under the ESA is no longer necessary. Section 4(a)(3)(A) of the ESA (16
U.S.C. 1533(a)(3)(A)) requires that, to the extent prudent and
determinable, critical habitat be designated concurrently with the
listing of a species. Critical habitat shall not be designated in
foreign countries or other areas outside U.S. jurisdiction (50 CFR
424.12 (h)).
The best available scientific and commercial data as discussed
above identify the geographical areas occupied by the narrow sawfish
(A. cuspidata), dwarf sawfish (P. clavata), green sawfish (P. zijsron),
largetooth sawfish (P. pristis), and the non-U.S. DPS of smalltooth
sawfish (P. pectinata) are found entirely outside U.S. jurisdiction so
we cannot designate critical habitat for these species. We can
designate critical habitat in unoccupied areas if the area(s) are
determined by the Secretary to be essential for the conservation of the
species. Regulations at 50 CFR 424.12 (e) specify that we shall
designate as critical habitat areas outside the geographical range
presently occupied by the species only when the designation limited to
its present range would be inadequate to ensure the conservation of the
species.
The best available scientific and commercial information on the
species does not indicate that U.S. waters provide any specific
essential biological function other than general foraging opportunities
for the largetooth sawfish (P. pristis). All records of P. pristis in
U.S. waters were larger animals (adults). We are unaware of any record
of a juvenile largetooth sawfish in U.S. waters, which suggest the
species does not use the area for a nursery. The majority of reports
for the largetooth sawfish in U.S. waters are during the summer months
when water temperatures are warmer. We have no reports of the species
that would suggest U.S. waters are used for breeding. Based on the best
available information we have not identified unoccupied area(s) that
are currently essential to the conservation of any of the sawfishes
proposed for listing. Therefore, based on the available information we
do not intend to designate critical habitat for the narrow, dwarf,
largetooth, green, or the non-U.S. DPS of smalltooth sawfish.
Identification of Those Activities That Would Constitute a Violation of
Section 9 of the ESA
On July 1, 1994, NMFS and FWS published a policy (59 FR 34272) that
requires us to identify, to the maximum extent practicable at the time
a species is listed, those activities that would or would not
constitute a violation of section 9 of the ESA. Because we are
proposing to list all six sawfishes as endangered, all of the
prohibitions of Section 9(a)(10) of the ESA will apply to all six
species. These include prohibitions against the import, export, use in
foreign commerce, or ``take'' of the species. Take is defined as ``to
harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or
collect, or to attempt to engage in any such conduct.'' These
prohibitions apply to all persons subject to the jurisdiction of the
United States, including in the U.S. or on the high seas. The intent of
this policy is to increase public awareness of the effects of this
listing on proposed and ongoing activities within the species' range.
Activities that we believe could result in a violation of section 9
prohibitions of these six sawfishes include, but are not limited to,
the following:
(1) Take within the U.S. or its territorial sea, or upon the high
seas;
(2) Possessing, delivering, transporting, or shipping any sawfish
part that was illegally taken;
(3) Delivering, receiving, carrying, transporting, or shipping in
interstate or foreign commerce any sawfish or sawfish part, in the
course of a commercial activity, even if the original taking of the
sawfish was legal;
(4) Selling or offering for sale in interstate commerce any sawfish
part, except antique articles at least 100 years old;
(5) Importing or exporting sawfish or any sawfish part to or from
any country;
(6) Releasing captive sawfish into the wild. Although sawfish held
non-commercially in captivity at the time of listing are exempt from
certain prohibitions, the individual animals are considered listed and
afforded most of the protections of the ESA, including most
importantly, the prohibition against injuring or killing. Release of a
captive animal has the potential to injure or kill the animal. Of an
even greater conservation concern, the release of a captive animal has
the potential to affect wild populations of sawfish through
introduction of diseases or inappropriate genetic mixing. Depending on
the circumstances of the case, NMFS may authorize the release of a
captive animal through a section 10(a)(1)(a) permit;
(7) Harming captive sawfish by, among other things, injuring or
killing a captive sawfish, through experimental or potentially
injurious veterinary care of conducting research or breeding activities
on captive sawfish, outside the bounds of normal animal husbandry
practices. Captive breeding of sawfish is considered experimental and
potentially injurious. Furthermore, the production of sawfish progeny
has conservation implications (both positive and negative) for wild
populations. Experimental or potentially injurious veterinary
procedures and research or breeding activities of sawfish may,
depending on the circumstances, be authorized under an ESA 10(a)(1)(a)
permit for scientific research or the enhancement of the propagation or
survival of the species.
We will identify, to the extent known at the time of the final
rule, specific activities that will not be considered likely to result
in a violation of section 9. Although not binding, we are considering
the following actions, depending on the circumstances, as not being
prohibited by ESA Section 9:
(1) Take of a sawfish authorized by a 10(a)(1)(a) permit authorized
by, and carried out in accordance with the terms and conditions of an
ESA section 10(a)(1)(a) permit issued by NMFS for purposes of
scientific research or the enhancement of the propagation or survival
of the species;
(2) Incidental take of a sawfish resulting from Federally
authorized, funded, or conducted projects for which consultation under
section 7 of the ESA has been completed, and when the otherwise lawful
activity is conducted in accordance with any terms and conditions
granted by NMFS in an incidental take statement in a biological opinion
pursuant to section 7 of the ESA;
(3) Continued possession of sawfish parts that were in possession
at the time of listing. Such parts may be non-commercially exported or
imported; however the importer or exporter must be able to provide
sufficient evidence to show that the parts meet the criteria of ESA
section 9(b)(1) (i.e., held in a controlled environment at the time of
listing, non-commercial activity).
(4) Continued possession of live sawfish that were in captivity or
in a controlled environment (e.g., in aquaria) at the time of this
listing, so long as the prohibitions under ESA section 9(a)(1) are not
violated. Again, facilities should be able to provide evidence that the
[[Page 33323]]
sawfish were in captivity or in a controlled environment prior to
listing. We suggest such facilities submit information to us on the
sawfish in their possession (e.g., size, age, description of animals,
and the source and date of acquisition) to establish their claim of
possession (see For Further Information Contact); and
(5) Provision of care for live sawfish that were in captivity at
the time of listing. These individuals are still protected under the
ESA and may not be killed or injured, or otherwise harmed, and,
therefore, must receive proper care. Normal care of captive animals
necessarily entails handling or other manipulation of the animals, and
we do not consider such activities to constitute take or harassment of
the animals so long as adequate care, including adequate veterinary
care is provided. Such veterinary care includes confining,
tranquilizing, or anesthetizing sawfish when such practices,
procedures, or provisions are not likely to result in injury; and
(6) Any interstate and foreign commerce trade of sawfishes already
in captivity that is conducted under a CITES permit.
Section 11(f) of the ESA gives NMFS authority to promulgate
regulations that may be appropriate to enforce the ESA. Future
regulations may be promulgated to regulate trade or holding of sawfish,
if necessary. The public will be given the opportunity to comment on
future proposed regulations.
Role of Peer Review
In December 2004, the Office of Management and Budget (OMB) issued
a Final Information Quality Bulletin for Peer Review establishing a
minimum peer review standard. Similarly, a joint NMFS/FWS policy (59 FR
34270; July 1, 1994) requires us to solicit independent expert review
from qualified specialists, concurrent with the public comment period.
The intent of the peer review policy is to ensure that listings are
based on the best scientific and commercial data available. We
solicited peer review comments on this 12-month finding and proposed
rule from three NMFS scientists familiar with elasmobranchs and their
comments are incorporated into this document. All three peer reviewers
supported our determinations. Prior to a final listing, we will solicit
the expert opinions of several qualified specialists selected from the
academic and scientific community, Federal and State agencies, and the
private sector on listing recommendations to ensure the best biological
and commercial information is being used in the decision-making
process, as well as to ensure that reviews by recognized experts are
incorporated into the review process of rulemakings developed in
accordance with the requirements of the ESA.
We will consider peer review comments in making our determination,
and include a summary of the comments and recommendations, if a final
rule is published.
References
A complete list of the references used in this proposed rule is
available upon request (see ADDRESSES).
Classification
National Environmental Policy Act
The 1982 amendments to the ESA, in section 4(b)(1)(A), restrict the
information that may be considered when assessing species for listing.
Based on this limitation of criteria for a listing decision and the
opinion in Pacific Legal Foundation v. Andrus, 675 F. 2d 825 (6th Cir.
1981), NMFS has concluded that ESA listing actions are not subject to
the environmental assessment requirements of the National Environmental
Policy Act (NEPA) (See NOAA Administrative Order 216-6).
Executive Order 12866, Regulatory Flexibility Act, and Paperwork
Reduction Act
As noted in the Conference Report on the 1982 amendments to the
ESA, economic impacts cannot be considered when assessing the status of
a species. Therefore, the economic analysis requirements of the
Regulatory Flexibility Act are not applicable to the listing process.
In addition, this proposed rule is exempt from review under Executive
Order 12866. This proposed rule does not contain a collection-of-
information requirement for the purposes of the Paperwork Reduction
Act.
Executive Order 13132, Federalism
In accordance with E.O. 13132, we determined that this proposed
rule does not have significant Federalism effects and that a Federalism
assessment is not required. In keeping with the intent of the
Administration and Congress to provide continuing and meaningful
dialogue on issues of mutual state and Federal interest, this proposed
rule will be given to the relevant governmental agencies in the
countries in which the species occurs, and they will be invited to
comment. NMFS will confer with U.S. Department of State to ensure
appropriate notice is given to foreign nations within the range of all
five species. As the process continues, NMFS intends to continue
engaging in informal and formal contacts with the U.S. State
Department, giving careful consideration to all written and oral
comments received.
Public Comments Solicited
We intend that any final action resulting from this proposal will
be as accurate as possible and informed by the best available
scientific and commercial information. Therefore, we request comments
or information from the public, other concerned governmental agencies,
the scientific community, industry, environmental groups or any other
interested party concerning this proposed rule. We particularly seek
comments containing:
(1) Information concerning the location(s) of any sightings or
captures of the species;
(2) Information concerning the threats to the species;
(3) Taxonomic information on the species;
(4) Information related to the determination of a non-U.S. DPS of
smalltooth sawfish;
(5) Efforts being made to protect the species throughout their
current range;
(6) Information on the aquaria trade of these species; and
(7) Information on the movement patterns of smalltooth sawfish.
Public hearing requests must be made by July 19, 2013.
List of Subjects in 50 CFR Part 224
Administrative practice and procedure, Endangered and threatened
species, Exports, Imports, Reporting and recordkeeping requirements,
Transportation.
Dated: May 29, 2013.
Alan D. Risenhoover,
Director, Office of Sustainable Fisheries, performing the functions and
duties of the Deputy Assistant Administrator for Regulatory Programs,
National Marine Fisheries Service.
For the reasons set out in the preamble, 50 CFR part 224 is
proposed to be amended as follows:
PART 224--ENDANGERED MARINE AND ANADROMOUS SPECIES
0
1. The authority citation for part 224 continues to read as follows:
Authority: 16 U.S.C. 1531-1543 and 16 U.S.C. 1361 et seq.
0
2. In Sec. 224.101, paragraph (a), revise the entries in the table for
``Smalltooth sawfish'' and ``Largetooth sawfish'', and add new entries
for four new species the ``Narrow Sawfish'', ``Dwarf Sawfish'',
``Smalltooth Sawfish, Non-U.S. DPS'', and ``Green Sawfish'' at the end
of the table to read as follows:
[[Page 33324]]
Sec. 224.101 Enumeration of endangered marine and anadromous species.
* * * * *
(a) * * *
----------------------------------------------------------------------------------------------------------------
Species Citation(s) for Citation(s) for
-------------------------------------------------- Where Listed listing critical habitat
Common name Scientific name determination(s) designation(s)
----------------------------------------------------------------------------------------------------------------
* * * * * * *
Smalltooth Sawfish, U.S. DPS.. Pristis pectinata Everywhere Found 68 FR 15674, Apr. 74 FR 45353, Sept. 2,
U.S.A.. 1, 2003. 2009.
* * * * * * *
Largetooth sawfish............ Pristis pristis Everywhere Found. 76 FR 40835, July NA.
(Pristis 12, 2011.
microdon)
(Pristis
perotteti).
* * * * * * *
Narrow Sawfish................ Anoxypristis Everywhere Found. [Federal Register NA.
cuspidata. citation and date
when published as
a final rule].
Dwarf Sawfish................. Pristis clavata.. Everywhere Found. [Federal Register NA.
citation and date
when published as
a final rule].
Smalltooth Sawfish, Non-U.S. Pristis pectinata Everywhere Found [Federal Register NA.
DPS. Outside U.S. citation and date
Waters. when published as
a final rule].
Green Sawfish................. Pristis zijsron.. Everywhere Found. [Federal Register NA.
citation and date
when published as
a final rule].
----------------------------------------------------------------------------------------------------------------
\1\ Species includes taxonomic species, subspecies, distinct population segments (DPSs) (for a policy statement,
see 61 FR 4722, February 7, 1996), and evolutionarily significant units (ESUs) (for a policy statement, see 56
FR 58612, November 20, 1991).