5/18/2015  |   10:30 - 10:45   |  102B

REGULATION AND RESULTS: BIOTIC AND ABIOTIC CHANGES TO NORTHEASTERN LAKES FOLLOWING TIGHTENING OF AIR EMISSIONS RULES The Clean Air Act Amendments of 1990 reduced emissions of sulfur and other pollutants, and reduced acidic precipitation. USEPA’s ELS-II survey of 158 northeastern lakes in 1986 took water quality measurements and zooplankton samples, and found that many lakes were stressed by high acidity. In 2004, these lakes were re-surveyed to determine the effects of reduced precipitation acidity. We compared water quality metrics between 1986 and 2004 using paired t-tests. Using a linear mixed effects model, we examined changes in zooplankton lengths between sampling dates, using lake as a random variable and controlling for shifts in zooplankton taxa. Both sulfate and nitrate concentrations were significantly lower in 2004 (-20.97 and -0.520 ?eq/L, respectively), with larger declines observed for sulfate. Zooplankton were significantly longer in 2004, and this difference was significantly correlated with higher acid neutralizing capacity (p<0.0001) and lower sulfate concentrations (p<0.0001). These results indicate that lakes are experiencing both biotic and abiotic changes in response to tighter emissions controls. Future work will examine how zooplankton communities have shifted at the species level in response to changing deposition.

William G. McDowell (Primary Presenter/Author), Merrimack College, wgmcdowell@gmail.com;


Katherine Webster (Co-Presenter/Co-Author), Trinity College Dublin, websterk@tcd.ie;


Sarah Nelson (Co-Presenter/Co-Author), Appalachian Mountain Club, sarah.j.nelson@maine.edu;


William H McDowell (Co-Presenter/Co-Author), University of New Hampshire, bill.mcdowell@unh.edu;


James Haney (Co-Presenter/Co-Author), Department of Biological Sciences, University of New Hampshire, Durham, NH, Jim.Haney@unh.edu;

5/18/2015  |   10:45 - 11:00   |  102B

RESPONSE OF FISH ASSEMBLAGES TO CHANGING ACID-BASE CHEMISTRY IN ADIRONDACK LONG TERM MONITORING LAKES, 1984-2012. Fish assemblages and water chemistry in 52 Adirondack Mountain lakes were sampled by the Adirondack Lakes Survey Corporation and the New York State Department of Environmental Conservation (NYSDEC) during three periods (1984-87, 1994-2005, and 2008-12) to document regional effects of acidic deposition and to assess recovery associated with the 1990 Clean Air Act Amendment (CAAA). Preliminary analysis of changes between 1984-1987 and 1994-2005 identified mixed recoveries and several community response/recovery classes and devised a fish-community index. The U.S. Geological Survey, NYSDEC, and Syracuse University are beginning a more rigorous analysis of recent data to assess effects of the 1990 CAAA between 1984-87 and 2008-12. Water chemistry and fish-community composition, species richness, and catch-per-unit-effort (CPUE) data indicate that measureable recovery has occurred in some of the study lakes between the first and second surveys. Additional univariate and multivariate analyses of richness and CPUE data and MDS ordination of community-composition data from the three periods will be presented to determine whether the 1990 CAAA has improved water quality sufficiently to permit continued reintroduction of native fishes in lakes across the Adirondack region.

Barry Baldigo (Primary Presenter/Author), U.S. Geological Survey, bbaldigo@usgs.gov;


Karen Roy (Co-Presenter/Co-Author), NY State Department of Environmental Conservation, karen.roy@dec.ny.gov;

5/18/2015  |   11:00 - 11:15   |  102B

FISH INTRODUCTION, FACILITATED BY UNEXPECTED RECOVERY FROM ACIDIFICATION, CAUSES A TROPHIC CASCADE IN LAKE MINNEWASKA, NY Lakes within managed forests are largely protected from the impacts associated with human-dominated land uses, and thus present an opportunity to study the indirect impacts of humans on lake ecosystems. We link acid rain and fish introductions as the drivers of lake ecosystem change in the Sky Lakes, a collection of five lakes within managed lands on the Shawangunk Ridge in New York State. First, we used long-term data to determine how lake pH is changing over the past 25 years in the Sky Lakes. Our three focal lakes all showed decreases in lake acidity but at significantly different rates indicating multiple drivers of this change. Second, we asked if a newly introduced fish species into a previously fishless lake (Lake Minnewaska) has caused ecosystem wide changes to the lake structure and function. A trophic cascade resulted in increased algal biomass and decreased water clarity mediated by decreasing zooplankton size and biomass. Together, increasing pH and an introduced species have combined to change the ecological community and function in a popular recreational lake.

Ben Albers (Co-Presenter/Co-Author), SUNY New Paltz, n02528711@hawkmail.newpaltz.edu;


David Charifson (Co-Presenter/Co-Author), SUNY Stony Brook, david.charifson@stonybrook.edu;


Valerie Stanson (Co-Presenter/Co-Author), SUNY New Paltz, n02444501@hawkmail.newpaltz.edu;


Erich Stern (Co-Presenter/Co-Author), SUNY New Paltz, rhoadie527@gmail.com;


John Thompson (Co-Presenter/Co-Author), Mohonk Preserve, jthompson@mohonkpreserve.org;


David Richardson (Primary Presenter/Author), SUNY New Paltz, Department of Biology, richardsond@newpaltz.edu;

5/18/2015  |   11:15 - 11:30   |  102B

EFFICACY OF DIRECT APPLICATION LIMING FROM A METAPOPULATION PERSPECTIVE Direct application stream liming is commonly used to treat the legacy effects of acid deposition, but its efficacy has been questioned due to the lack of fish recovery with treatment. When considering effectiveness, connectivity to neutral streams is rarely considered, and Brook Trout (Salvelinus fontinalis) populations are treated as closed entities. If Brook Trout utilize poor breeding habitat for superior foraging habitat and move between populations, liming should be continued to support the highly mobile, landscape level population. I sampled Brook Trout population parameters (density, biomass, and age structure) and diet (via gut contents and stable isotopes) in six central Appalachian mountain streams. While most water chemical conditions in treated stream reaches corresponded to naturally neutral reference streams, fish (density, biomass, age class structure) were similar to untreated acidic streams. Gut contents of Brook Trout did not vary among treatments; however isotope signatures of their muscle tissue indicated different food sources and trophic position among treatments. Considering the dynamics of an open system, these results support that there is movement between patch populations for optimal foraging and decreased competition.

Natasha Wingerter (Primary Presenter/Author), University of Idaho, wing4979@vandals.uidaho.edu;

5/18/2015  |   11:30 - 11:45   |  102B

CHEMICAL AND BIOLOGICAL RECOVERY FROM ACID DEPOSITION WITHIN THE HONNEDAGA LAKE WATERSHED, NEW YORK, USA The recovery of heritage brook trout in a 312 ha Adirondack lake subject to extensive acidification provides a comprehensive example of the response of an aquatic ecosystem to the Clean Air Act Amendments of 1990. Cornell University researchers began Honnedaga Lake studies in the 1950s, but stopped surveying the lake in the 1970s when the brook trout population was considered to be functionally extirpated. Brook trout were next captured in the main body of the lake two decades later, indicating that the lake had been re-colonized from a few well-buffered tributary refuges as in-lake concentrations of sulfate, nitrate, and inorganic monomeric aluminum declined. By contrast, no changes have been observed in acid-neutralizing capacity (ANC) or calcium. Recent increases in chlorophyll a and decreases in water clarity reflect a concurrent increase in phytoplankton abundance, though the zooplankton community exhibits low species richness with a scarcity of acid sensitive Daphnia and dominance by acid-tolerant copepods. Recent surveys have documented a steady increase in brook trout abundance, reflecting an ongoing recovery of chemistry and biota in this lake.

Clifford Kraft (Primary Presenter/Author), Cornell University, cek7@cornell.edu;


Daniel Josephson (Co-Presenter/Co-Author), Cornell University, dcj3@cornell.edu;


Kurt Jirka (Co-Presenter/Co-Author), Cornell University, kjj23@cornell.edu;

5/18/2015  |   11:45 - 12:00   |  102B

NUTRIENT UPTAKE DYNAMICS IN ACID-STRESSED AND LIME AMENDED ADIRONDACK MOUNTAIN STREAMS The Adirondack Mountain region of New York State continues to suffer from the effects of acid deposition and one mitigation strategy is to add pelletized limestone directly to stream channels or across entire drainage basins to neutralize incoming acid. We studied the impact of lime amendments in 5 streams, 2 are chronically acidic, and 3 are episodically acidic. Lime has been applied annually to stream channels in 2 episodically acid streams beginning in 2012, and in 2013 we aerially applied lime to a whole drainage basin of 1 chronically acid stream. We conducted short-term nutrient uptake experiments in the summer and autumn of 2014 using ammonium and phosphate and compared uptake lengths, uptake rates and uptake velocities among streams. There was no relationship between any uptake metric and level of acidity nor was there any consistent difference in uptake metrics between the summer and autumn. Uptake lengths were greater for ammonium than phosphate but that was likely the result of higher ammonium than phosphate concentrations in the streams. Our results suggest nutrient uptake is not significantly affected in acid-stressed streams.

Randy Fuller (Primary Presenter/Author), Colgate University, rfuller@colgate.edu;


Grant Haines (Co-Presenter/Co-Author), Colgate University, ghaines@colgate.edu;


James Paris (Co-Presenter/Co-Author), Colgate University, jparis@colgate.edu;


Wesley Morgan (Co-Presenter/Co-Author), Colgate University, wmorgan@colgate.edu;