The New York State Department of Environmental Conservation (DEC) and the Adirondack Lakes Survey Corporation (ALSC) have announced the confirmation of brook trout in Lake Colden in the Adirondack High Peaks.
Considered fishless for decades due to the negative effects of acid rain, the discovery of the brook trout population in Lake Colden is being attributed to improved water quality directly resulting from state and national standards to prevent the airborne pollutants that cause acid rain, notably sulfur dioxide.
According to data from the from the Whiteface Mountain Atmospheric Sciences Research Center, part of the National Atmospheric Deposition Program, there has been a 90% reduction in sulfur dioxide deposition in the Adirondacks since 1995. That reduction is now under threat, according to advocates, who say that the Republican administration of Donald Trump is rolling back protections against pollution from mid-western coal fired power plants. Those plants contribute to the Adirondack Park’s acid rain problems.
The Lake Colden brook trout discovery is believed to be the first time a sustaining fish population has been recorded in a high-elevation (2,764 feet) Adirondack lake previously determined to be unable to host fish due to acid rain impacts. High-elevation lakes and their brook trout populations were severely impacted by acid rain.
How Air Quality Impacted Lake Colden’s Brook Trout
Acid rain comes in many forms – rain, snow, sleet, hail, and fog (wet deposition), and as deposits of acid particles, aerosols, and gases (dry deposition). Acid rain is formed when sulfur dioxide (SO2) and nitrogen oxides (NOx) combine with moisture in the atmosphere to produce sulfuric acid and nitric acid. Several sources that contribute to creating acid rain include the combustion of fossil fuels (coal, oil, natural gas, wood, etc.); emissions from motor vehicles, airplanes, power plants, and industries; and emissions of SO2 and NOx carried atmospherically from the Midwest.
By the 1960s, scientists determined that acid deposition was devastating natural resources across New York. The Catskill and Adirondack Parks were particularly hard hit. Soils were becoming too acidic to maintain healthy forests with noticeable tree die-offs at higher elevations. Many lakes, mountain streams, and some rivers were unable to support healthy fish populations. Lake Colden was considered fishless after a 1987 ALSC survey caught no fish. Subsequent surveys in 2004 and 2011 also failed to catch any fish.
New York State began taking steps to control SO2 and NOx pollution in the 1980s, including the 1984 Acid Deposition Control Act. The state also successfully advocated for amendments to the Clean Air Act in 1990 to require federal controls of SO2 and NOx. DEC undertook additional actions in the 1990s and 2000s to reduce in-state sources of pollution through the Acid Deposition Reduction Program. As a result of these and other steps taken at DEC’s urging and by the ALSC, New York State Energy Research and Development Authority’s (NYSERDA) atmospheric deposition initiatives, U.S. Environmental Protection Agency’s Clean Air Markets Division, United States Geological Survey, Syracuse University, among many others, acid rain precursors are emitted at a significantly lower level than before 1985.
Water samples from Lake Colden and 51 other designated Adirondack Long-Term Monitoring (ALTM) lakes are collected and analyzed several times per year. Since summer 1992, ALSC staff have conducted the field, laboratory, and public posting of data in collaboration with ALTM partners. The ALTM partnership and monitoring efforts continues and more information can be found at DEC’s website. Lake samples are tested for pH and other related water chemistry parameters. In recent years, samples had shown that the water quality was improving.
Using DEC-derived information in August, ALSC staff sought and observed small brook trout in a tributary to Lake Colden while collecting water samples. DEC’s Division of Fish and Wildlife followed up by hiking in nets and electroshocking equipment in September to sample fish populations in the lake and its tributaries. During sampling, DEC discovered the lake contained a what it considers a viable and healthy population of three generations of brook trout and found brook trout in a lake tributary. DEC is undertaking genetic testing to determine the origin of the brook trout population, which could be a native heritage. DEC Fisheries program staff are also monitor the brook trout population.
One of the highest ALTM sites, the Lake Colden watershed extends to 5,114 feet near Algonquin Peak. This 38-acre lake is located between Mount Colden, the McIntyre Range, and Mount Marshall amid some of the most scenic parts of the Adirondacks. Anglers willing to make the arduous hike to Lake Colden to fish for this newly discovered brook trout population must be aware the use of baitfish is prohibited in the lake.
Learn more about New York’s official State fish, the brook trout, on DEC’s website.
ALSC helps monitor changes to natural ecosystems of the Adirondack Mountain ecological zone with a focus on water quality, atmospheric deposition, fish surveys, and other biological and chemical studies. More information about their work can be found on ALSC’s website.
Photo of Brook Trout (from another location) by Greg Dower.