Scott O. Quinn

A Phosphorus Budget, Model, and Load Reduction Strategy For Lake Champlain

ABSTRACT A phosphorus budget and mass balance model were developed for Lake Champlain in order to identify load reductions necessary to attain interim in-lake total phosphorus concentration criteria established in a water quality agreement between New York, Quebec, and Vermont Total phosphorus loadings were measured from 31 tributaries, 88 wastewater discharges, and direct precipitation. Mean annual tributary loadings were estimated using the FLUX program (Walker 1987). The total base year phosphorus loading rate of 647 mt·yr−1 included 29% from point sources, 47% from cultural nonpoint sources, and 24% from natural sources. A mass balance model for 13 lake segments was developed and calibrated to the data using the BATHTUB program (Walker 1987). Exchange flows between lake segments were evaluated using a mass balance for chloride. The BATHTUB program error analysis procedure was used to evaluate model prediction uncertainty, based on variance estimates for all input data terms. The modeling results were ...

Brooktrout Lake case study: biotic recovery from acid deposition 20 years after the 1990 Clean Air Act Amendments.

The Adirondack Mountain region is an extensive geographic area (26,305 km(2)) in upstate New York where acid deposition has negatively affected water resources for decades and caused the extirpation of local fish populations. The water quality decline and loss of an established brook trout (Salvelinus fontinalis [Mitchill]) population in Brooktrout Lake were reconstructed from historical information dating back to the late 1880s. Water quality and biotic recovery were documented in Brooktrout Lake in response to reductions of S deposition during the 1980s, 1990s, and 2000s and provided a unique scientific opportunity to re-introduce fish in 2005 and examine their critical role in the recovery of food webs affected by acid deposition. Using C and N isotope analysis of fish collagen and state hatchery feed as well as Bayesian assignment tests of microsatellite genotypes, we document in situ brook trout reproduction, which is the initial phase in the restoration of a preacidification food web structure in Brooktrout Lake. Combined with sulfur dioxide emissions reductions promulgated by the 1990 Clean Air Act Amendments, our results suggest that other acid-affected Adirondack waters could benefit from careful fish re-introduction protocols to initiate the ecosystem reconstruction of important components of food web dimensionality and functionality.

The Effect of Terrigenous Inputs on Spatial Patterns of Water Quality Indicators in South Lake, Lake Champlain

Spatial patterns of measures of trophic state, optical properties and particle composition are documented for Lake Champlain, with particular emphasis on the southernmost shallow section (< 10 m deep, ∼ 55 km in length) known as South Lake, to depict the impacts of terrigenous inputs. The analysis is supported by two surveys conducted in 1998 for South Lake (thirteen sites) following typical and unusually high runoff intervals, and for selected deep-water sites (thirteen) for the typical runoff interval. Terrigenous inputs, particularly as clays, cause light penetration to be lower, turbidity (Tn) and phosphorus (P) concentrations to be higher by a wide margin, and particle composition to differ greatly in South Lake relative to deeper portions of the lake. Generally progressive gradients are documented within South Lake for Secchi disc transparency (SD), the light attenuation coefficient, (Tn), particulate organic carbon, total P, and particulate P, that demonstrate diminishing impacts of the terrigenous inputs with the approach to the deeper portions of the lake. Increased loadings associated with high runoff impart greater, and a wider array of, impacts in South Lake, that appear to be relatively shortlived (less than 1 month). The high levels of inanimate particles (tripton) that prevail in South Lake systematically compromise total P concentration and SD as measures of trophic state. Despite lower levels, this terrigenous material also influences these measures in deep-water areas. Management strategies that focus on reductions in P loading will not result in substantive increases in SD in South Lake, as phytoplankton biomass is unimportant in regulating the prevailing clarity conditions. Erosion control may be a more promising alternative to pursue improved clarity in this portion of the lake.

Atmospheric and Watershed Inputs of Mercury to Cranberry Lake, St. Lawrence County, New York

Cranberry Lake is a large (28.2 km2) reservoir located in the northwestern Adirondack Mountains in New York State. The area surrounding the lake is primarily wilderness with no major industry. In 1969, fish collected from Cranberry Lake and nearby Stillwater Reservoir as part of a Statewide sample collection program yielded anomalously elevated mercury levels when compared to similar sized and aged fish of the same species from other lakes in the State. This paper documents studies conducted by New York State over the last ten years concerning the Cranberry Lake situation.

Nitrogen deposition and lake nitrogen concentrations: a regional analysis of terrestrial controls and aquatic linkages

Loading of nutrients from terrestrial ecosystems strongly influences the productivity and biogeochemistry of aquatic ecosystems. Human activities can supplement and even dominate nutrient loading to many lakes, particularly in agricultural and urbanized settings. For lakes in more remote regions such as the Adirondack Mountains of New York, N deposition represents the primary potential anthropogenic nutrient source. We combined a spatial model of N deposition with data on lake-N concentrations and spatial data on watershed configuration to identify the sources of watershed N loading for over 250 lakes in the Adirondacks. The analysis indicates that while wetlands are stronger sources of N loading per unit area than forests in the absence of inorganic N deposition, wetlands retain essentially all N deposition, while forests retained ∼87% of N deposition. Since forests cover close to 90% of the watersheds, upland forests are, on average, the single largest source of N loading to Adirondack lakes. Direct dep...

LAKE ACIDIFICATION AND THE BIOLOGY OF ADIRONDACK LAKES: CRUSTACEAN ZOOPLANKTON COMMUNITIES

ABSTRACT Fifty-five lakes in the Adirondack Mountains of New York were surveyed during 1982 for crustacean zooplankton, rotifers, phytoplankton, and water chemistry. The midsummer surface pH values ranged from 3.60 to 7.25. Lakes were selected in order to have a wide range of morphometry and watershed characteristics. Zooplankton species richness and diversity declined with pH. In lakes with pH less than 5.0, three species tended to dominate the growing season community. A discussion of the zooplankton communities in acidic lakes that have recently been treated with either agricultural limestone or sodium carbonate is included.

PLANKTON COMMUNITY RESPONSE TO THE CHEMICAL NEUTRALIZATION OF THREE ACIDIFIED WATERS IN THE ADIRONDACK MOUNTAIN REGION OF NEW YORK STATE

ABSTRACT The response of the phytoplankton and zooplankton communities of three acidic Adirondack lakes to chemical neutralization is reported. The addition of base to the three lakes effectively neutralized acid conditions, raising pH from ~4.50 to 6.02 to 7.3. Concentrations of major ions were generally unaffected by neutralization treatment but aluminum concentrations were reduced. The phytoplankton and planktonic rotifer communities were initially decimated by the water column treatments but recovered within the first growing season following treatment. Species richness and standing crops of phytoplankton and rotifers approached or exceeded pre-treatment values within a year of neutralization. The crustacean community was generally slower to respond to base additions. Phytoplankton, rotifer, and crustacean community composition was changed in all lakes following treatment.

A SIMULATION MODEL FOR ASSESSING THE SUCCESS OF AGRICULTURAL BEST MANAGEMENT PRACTICES ON SURFACE WATER QUALITY

A simulation model was used to assess how agricultural practices used to reduce soil erosion, such as no-till cropping, affect the plant nutrient and suspended sediment levels in streams. The model...