Brook trout return

Here is some great news: The Department of Environmental Conservation and the Adirondack Lakes Survey Corporation (ALSC) recently announced that they have confirmed the presence of brook trout in Lake Colden. This high-elevation lake in the High Peaks Wilderness had been devoid of brook trout for a long time as the result of acid rain.

The ALSC has monitored the chemistry of Adirondack lakes for decades, and its research efforts documented the improvements in the water chemistry of Lake Colden. The lake, like many high-elevation lakes in the Adirondacks, was impacted by acid rain. The acid rain phenomenon, caused by air pollutants being deposited in the watersheds of lakes and ponds, did a lot of damage in the Adirondacks. Pollutants like nitrate and sulfate combine with moisture in the atmosphere to produce sulfuric and nitric acids, decreasing the ph of the ponds and lakes to the acidic side of the scale, often to the point that fish like the brook trout could no longer inhabit them.

Lake Colden was surveyed in 1987, 2004, and 2011, and all three surveys found zero trout. Efforts to control air pollution that started in the 1980s and continue have been successful in reducing the sources of the pollutants that create acid rain, and they provided the good news in Lake Colden.

ALSC staff observed small brookies in a tributary to Lake Colden, and then DEC Division of Fish and Wildlife sampled the lake with nets and electroshocking equipment, discovering that at least three generations of brook trout were present in addition to the brookies ALSC found in the tributary.

The brook trout captured by DEC staff will undergo genetic testing to determine if the origin of this population is a native strain. Both the ALSC and DEC staff members will continue to