TROUT TAGGED, TESTED, STOCKED

HENDERSON — It looked a little like a grocery store checkout line, with a woman taking the measure of the goods, holding them up to a scanner, waiting for the beep, then dropping them into a container one by one as a man recorded numbers on a clipboard.

Then one of the items in the checkout lane wriggled free of Jana Lantry's grasp and took a dive onto the floor, splashing icy water onto nearby faces as it went.

The speckled, silver yearling lake trout was quickly back on the counter under the biologist's firm grasp, its length recorded, the small tab of its clipped adipose fin noted and its tagged head scanned, before Ms. Lantry dropped it into another bucket of fresh water.

In minutes Friday, the little fish, along with about 39,000 others held in tanks aboard the small barge, would be heading for the bottom of Lake Ontario, as part of the state Department of Environmental Conservation Region 6's annual fish stocking program.

This was the second load of the day and the last of about 20 this season that would add about 511,000 lake trout to Lake Ontario. Altogether, DEC stocks more than 1 million pounds of varied native fishes into the state's waterways each year, according to its Web site. The goal of the program is both to improve recreational fishing and to restore populations of native fish whose numbers and ability to reproduce naturally have dwindled because of contamination, interference with food supplies and competition by exotics.

An aquatic biologist for the department, Ms. Lantry sampled a bucketful of fish from each load to check their size and ensure the fish are properly clipped and tagged, identifying them as part of the stocking program. These year-old lake trout were bred and raised at a U.S. Department of Fish and Wildlife hatchery in White River, Vt., then shipped by truck in aerated tanks to Stony Point in Henderson, one of the DEC's five stocking sites for the fish.

"Usually we make it out a few times with the trucks before the sea gulls catch on," Ms. Lantry said.

The air above the boat was crowded with squawking gulls as the barge came to a stop, and men held a length of flexible metal pipe, maybe 8 inches in diameter, up to a valve on one of the truck's tanks. A few fish fell out as the men struggled to orient the other end of the pipe over the water. One of the men bent down, picked up the flopping fish and tossed them over the side as a wide stream began, sending scores of fish pouring into the lake.

Each tank was emptied in turn. Most of the fish would head to the lake bottom, but ones sick or agitated from their road trip skimmed along the surface, where a few dozen were picked up by the gulls.

Ms. Lantry said DEC isn't sure exactly how many of the yearlings would survive. It will take five years for them to mature and seven before they reach their peak spawning period, and each stage in their life presents different hurdles to their survival.

Each year, DEC conducts studies of the lake trout and other stock fish populations to gauge their numbers, health, diet and rate of natural reproduction. The magnetic tags help the agency decide what stocking techniques yield the best survival rates, identifying each fish's stocking point, age and origin.

The goal is to "restore a naturally reproducing population of lake trout across the Great Lakes," Ms. Lantry said.

"We've had 14 consecutive years of naturally reproduced lake trout," she said. "It's at a low level, but we want to see it really ramp up."

That's a tough goal. Since the early 1990s, the survival of stock populations of lake trout is much lower than it used to be. "One of our research priorities is figuring out why they're not surviving as well as they used to," she said.

Beginning next summer, this year's stocked yearling lake trout will start turning up in DEC study nets, each one offering biologists a clue to the health of the species and the health of the lake.