- Associated Press - Tuesday, April 7, 2015

ALBANY, N.Y. (AP) - While the brook trout is revered as the quintessential Adirondack fish, the yellow perch has a mixed reputation. It’s prized as an easy-to-catch and tasty panfish but scorned as a non-native competitor to trout.

Now, researchers at an Adirondack college are questioning whether yellow perch is really an “alien species.” Scientists at Paul Smith’s College say DNA analysis of 2,200-year-old lake sediment shows a long-term native status for perch.

The finding is of more than academic interest. The alien designation is used to justify “reclamation” projects that poison all the fish in a selected Adirondack lake so trout can be re-introduced without competitors.

The Paul Smith’s study questions whether it’s fair to use “non-native species” as a justification for killing perch.

“We now know that yellow perch are as native to the Adirondack uplands as brook trout,” said Paul Smith’s biologist Curt Stager, co-author of the perch DNA study published last month in the peer-reviewed online journal PLOS ONE.

The state Department of Environmental Conservation has no immediate plans to do a pond reclamation and wouldn’t make a fisheries biologist available to discuss the issue. But in an email statement, the agency said it is focused on the impact yellow perch have had on native brook trout populations rather than whether perch are native to the region.

The department said yellow perch are widespread in Adirondack waters, but brook trout are not. It said brook trout once occupied 94 percent of the acreage of ponded waters in the Saranac Lakes Wild Forest, but have declined to just 3 percent currently. The main reason for the decline is competing species such as yellow perch, the agency said. Most of the remaining waters containing brook trout are the result of active management such as liming to counteract effects of acid rain, reclamation and stocking, the department said.

Reclamation involves treating a pond with rotenone, a plant-derived pesticide that kills all the fish but has minimal impact on non-target species and breaks down quickly. While criticized by some environmental groups, the technique has been used widely by state and federal fisheries managers for decades.

For their study, researchers took sediment core samples from Lower St. Regis Lake beside the college campus. A biological survey in 1930 reported no yellow perch, so the scientists expected to find perch DNA only in the upper layers, reflecting recent times. They were surprised to find it in sediments more than 2,000 years old.

“Yellow perch may be a red herring - a symptom of something else going on in the lake rather than a cause of the changes,” Stager said in a telephone interview Monday.

“It looks like there’s more going on that we need to understand. If they were here with trout all along, why are they so much more numerous now?”



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