Lake trout hatched and raised at the Allegheny National Fish Hatchery have been stocked in Lake Erie and Lake Ontario since the early 1990s as an effort to re-establish self-sustaining populations in these lakes.
Historic populations disappeared during the 20th century. Evidence shows that lake trout are reproducing in the wild at Lake Ontario, but none do so yet at Lake Erie.
The hatchery now is tagging lake trout that soon will be released. Tags will show fisheries biologists whether lake trout were stocked or hatched in the wild, as well as other valuable information.
The hatchery is operated by the U.S. Fish and Wildlife Service. Their mission is to restore and enhance heritage fisheries for future Americans.
While this restoration effort is under way, the lake trout have been providing popular fisheries, particularly at Lake Erie where the only salmonids in competition for the attention of anglers are steelhead and brown trout. At Lake Ontario, chinook salmon and coho salmon attract most of the attention.
A 41-pound 8-ounce lake trout caught from Lake Erie in 2009 set the state record for New York. Pennsylvania's 29-pound 4-ounce state record lake trout was caught from Lake Erie this year.
Tagging is taking place three weeks earlier in preparation for fall stocking.
By tagging the fish, fishery biologists will be able to trace the roots of any fish that is later caught and examined.
It can be traced all the way back to the raceway where it was raised. Tags will provide data on age, sex, growth rate and strain. Tags, which are in the nose area, are about 1 millimeter in length, too small to be noticed by anglers.
In addition to tagging, the adipose fin is clipped from each lake trout. This provides quick evidence of the source of a lake trout, hatchery or wild.Aiding in the operation is a million-dollar trailer on loan from the New York State Department of Environmental Conservation. The Fish and Wildlife Service has four trailers like it operating on the upper Great Lakes.
The trailer automates the tagging operation, speeding it up considerably. Tagging by hand, about 25,000 lake trout could be tagged in a day. Using the trailer allows about 70,000 to be tagged per day.
Another advantage of the tagging trailer is that anesthetic does not have to be used. Because of this, the fish recover faster, and they start growing faster.
The tagging operation starts with the transfer of the lake trout into the trailer, a simple hand operation. Tagging is done in lots of 40,000.
Six nearly identical tagging stations are in the trailer. Fish are distributed to the stations based on size. The fish pass one by one through gates that divide them by length.
A camera views the fish and the adipose fins are clopped. Then the tag is added by inserting the head of the fish into a mold that matches its shape.
A trap door opens, allowing the fish to pass from the tagging mechanism. In one final step, a metal detector checks each fish to be sure it contains a tag.