Adirondack Region Of New York Research Articles

Mercury in remote Rocky Mountain lakes of Glacier National Park, Montana, in comparison with other temperate North American regions

We determined concentrations of mercury (Hg) and methylmercury (MeHg) in 12 pristine lakes of Glacier National Park (GNP) and compared our observations with data from published studies of remote lakes in north-central Wisconsin and the Adirondack region of New York. Despite marked differences in water chemistry, biology, and hydrogeology, concentrations of Hg and MeHg in all regions were strongly correlated with dissolved organic carbon (DOC). Variables related to the acid–base status of lake waters had secondary effects on the concentration of waterborne mercury species. Although Hg and MeHg were strongly correlated with DOC in all three regions, MeHg concentrations were lower and increased less per unit organic carbon in GNP lakes than in either Wisconsin or New York. In GNP lakes, MeHg averaged only 4 ± 2% (mean ± SD) of the Hg, while in Wisconsin and New York lakes MeHg averaged 10–14% of the Hg. Based on simple regression modelling, we estimate that the maximum MeHg fraction (MeHg/Hg) in dystrophic GNP lakes would be three- to six-fold lower than in Wisconsin or New York waters of similarly high DOC. Our results suggest that this regional difference involves factors regulating the net production of MeHg in lakes or watersheds.

Liming Dosages for Acid Lakes and Watersheds

As Walski clearly states, computing liming dosages for acid lakes is not straightforward. Liming as a remedial action for neutralizing acid surface waters requires accurate dose calculations because of the large mass of neutralizing agent required and because of the ecological consequences of overdosing. A majority oflake neutralization projects have been done using limestone as the neutralizing agent. Limestone is a natural choice because of its availability and relatively low cost. One disadvantage of limestone is the relatively slow dissolution kinetics. This low dissolution must be taken into account when calculating the appropriate dosage for limestone, since some of the applied limestone does not have a chance to dissolve before it settles to the bottom of the lake. In some cases the settled limestone will eventually dissolve, and in other cases it will be covered with detritus or become coated with chemical precipitates. In the latter cases little or no acid neutralization is accomplished. Accurate computation of limestone dosages requires a knowledge of the dissolution kinetics. Therefore, considerable research has been aimed at delineating these kinetics for acid lakes. Of equal importance, but unfortunately of less research interest, is the procedure used to calculate final pH. Olem (1991) provides a summary of these dosage calculation procedures. The most sophisticated of these assume that the lake will be in equilibrium with atmospheric carbon dioxide after the neutralizing agent has been added. For example, the dosing models proposed by Scheffe et al. (1986), DePinto et al. (1989), and Driscoll et al. (1982) used the open-system assumption to calculate the resultant pH. Interestingly, many of the procedures for predicting limestone dissolution assume that dissolving limestone particles are in equilibrium not with an open, but rather with a closed system (Olem 1991). The purpose of this forum discussion is to suggest that a closed system is a more appropriate assumption for calculating target pH. The basis for this suggestion is a lO-year neutralization study conducted at Wolf Pond, a 21 ha dimictic lake located in the Adirondack region of New York. In this study Wolf Pond was neutralized with NaHC03 • Since NaHC03 is extremely soluble, dissolution kinetics did not obfuscate the observations. Results of the study showed clearly that most of the lake behaves as a closed system relative to atmospheric carbon dioxide. This is demonstrated in Figs. 1 and 2 which are plots of in-situ measured pH versus pH calculated using openand closed-system equilibrium assumptions. Computation of pH was based on:

Joint application of an empirical and mechanistic model for regional lake acidification

The empirical direct distribution model for lake acidification is calibrated for use in an integrated assessment model which predicts the regional impact of an acid deposition control strategy. The calibration is based on the mechanistic Model of Acidification of Groundwater in Catchments (MAGIC). The models are applied jointly to a set of 33 statistically-selected lakes in the Adirondack region of New York. Calibration of the direct distribution model is based on a step-function application of acid deposition to MAGIC. Comparative evaluations of the resulting model predictions are made using historic deposition estimates and two alternative future deposition scenarios. The predictions of the direct distribution model match well the shapes and patterns of change of the regional distributions of ANC and pH predicted by MAGIC, the short- and medium-term dynamics of these changes, and the effect of including organic acids. However, small, long-term decreases in the fraction of incoming acid deposition neutralized by lakes and their watersheds predicted by MAGIC are not reproduced.

Long-term trends in the chemistry of precipitation and lake water in the Adirondack Region of New York, USA

Long-term changes in the chemistry of precipitation (1978–94) and 16 lakes (1982–94) were investigated in the Adirondack region of New York, USA. Time-series analysis showed that concentrations of SO4 2−, NO3 −, NH4 + and basic cations have decreased in precipitation, resulting in increases in pH. A relatively uniform rate of decline in SO4 2− concentrations in lakes across the region (1.81±0.35 μeq L−1 yr−1) suggests that this change was due to decreases in atmospheric deposition. The decrease in lake SO4 2− was considerably less than the rate of decline anticipated from atmospheric deposition. This discrepancy may be due to release of previously deposited SO4 2− from soil, thereby delaying the recovery of lake water acidity. Despite the marked declines in concentrations of SO4 2− in Adirondack lakes, there has been no systematic increase in pH and ANC. The decline in SO4 2− has corresponded with a near stoichiometric decrease in concentrations of basic cations in low ANC lakes. A pattern of increasing NO3 − concentrations that was evident in lakes across the region during the 1980's has been followed by a period of lower concentrations. Currently there are no significant trends in NO3 − concentrations in Adirondack lakes.

Short‐Term Responses of Wetland Vegetation After Liming of an Adirondack Watershed

Watershed liming has been suggested as a long—term mitigation strategy for lake acidity, particularly in areas subject to high levels of acidic deposition.However, virtually no information has been available on the impacts of liming on wetland vegetation. In 1989, 1100 Mg of limestone (83.5% CaCO3) were aerially applied to 48% (100 ha) of the Woods Lake watershed in the west—central Adirondack region of New York as part of the first comprehensive watershed liming study in North America. We inventoried wetland vegetation in 1.0—m2 plots before liming and during the subsequent 2 yr. Within this period liming influenced the cover, frequency, or importance values of only 6 of 64 wetland taxa. The cover of Sphagnum spp. and of the cespitose sedge Carex interior decreased in control relative to limed plots, and cover of the rhizomatous sedge Cladium mariscoides increased nearly threefold in limed areas. These two sedges, which are relatively tall, are characteristic of more calcareous habitats. Cover of the grass Muhlenbergia uniflora, cover and importance value of the sundew Drosera intermedia, and frequency of the forb Hypericum canadense were adversely affected or inhibited by lime. It is unclear whether liming directly inhibited the growth of these three small—statured species, or whether the adverse effects of lime were mediated through shifts in competitive interactions with other species. The limited responses that we observed to liming, along with changes that occurred in control plots over the study period, may indicate that in the short term watershed liming was no more of a perturbation than the environmental factors responsible for natural annual variation in wetland communities.

Assessing Trends in Fishery Resources and Lake Water Aluminum from Paleolimnological Analyses of Siliceous Algae

Lake water aluminum concentrations have a significant influence on the composition of microfossil assemblages of diatoms and chrysophytes deposited in lake sediments. With the paleolimnological approach of multilake datasets in the Adirondack region of New York, USA, we use canonical correspondence analysis to describe past trends in lake water Al. Four lakes, previously investigated regarding acidification and fishery trends, are used to demonstrate that paleolimnological assessment can also provide direction, timing, and magnitude of trends for both toxic metals and fish resources. Additionally, we use weighted averaging regression and calibration to obtain quantitative reconstructions of past lake water Al concentrations. Such reconstructions provide further insight into fishery resource damage and can be compared with modelling results. According to paleolimnological reconstructions, some (albeit few) of the naturally most acidic lakes in the Adirondack region had preindustrial lake water concentrations of inorganic monomeric Al near 4 μmol∙L−1. Although these high concentrations are surprising from a geochemical point of view, they may partially explain the preindustrial absence of fish, as has been independently determined by paleolimnological analysis of phantom midges (Chaoborus). Fishery resource deterioration in acidified Adirondack lakes was coincident with major increases in lake water Al concentrations.

Weighted Multicollinearity in Logistic Regression: Diagnostics and Biased Estimation Techniques with an Example from Lake Acidification

An historical data set from the Adirondack region of New York is revisited to study the relationship between water chemistry variables associated with acid precipitation and the presence/absence of brook trout (Salvelinus fontinalis) and lake trout (Salvelinus namaycush). For the trout species data sets, water chemistry variables associated with acid precipitation, for example pH and alkalinity, are highly correlated. Regression models to assess their effects on the probability of the presence of fish species are therefore affected by multicollinearity. Because the appropriate regressions are logistic, correction techniques based on least squares do not work. Maximum likelihood parameter estimation is highly unstable for the trout presence/absence data. Developments in weighted multicollinearity diagnostics are used to evaluate maximum likelihood logistic regression parameter estimates. Further, an application of biased parameter estimation is presented as an option to the traditional maximum likelihood logistic regression. Biased estimation methods, like ridge, principal component, or Stein estimation can substantially reduce the variance of the parameter estimates and prediction variance for certain future observations. In many cases, only a slight modification to the converged maximum likelihood estimator is necessary.

Sequentially extracted metals in Adirondack lake sediment cores

Metal deposition patterns have been examined in sediment cores from three lakes in the Adirondack region of New York (USA). Sequential chemical extraction of Al, Fe, Mn, Pb, and Zn has yielded information on their chemical nature and potential mechanisms involved in their deposition. Results indicate historical changes in watershed chemistry may have influenced metal chemistry in these lakes. Detailed descriptions of the chemical forms of metals in sediments is not possible due to the fact that extraction methods are only operational. However, in two systems known to have been acidified in recent time by acidic deposition (Big Moose L. & Deep L.), concentrations of labile Al (in C1−C4 fraction) increase after 1940–1950, corresponding with lake acidification as inferred from diatom assemblages. Temporal trends in the inputs of Pb in the C1−C4 fraction are also consistent with known historical changes in atmospheric Pb inputs to the region. Chemical stratigraphies of Fe and Mn are most likely dominated by internal biogeochemical cycling within sediments.

Modeling Thermal Stratification in Transparent Adirondack Lake

A mixed‐layer thermal stratification model was calibrated for Woods Lake, a shallow acidic transparent lake located in the Adirondack region of New York, for most of the non‐ice‐cover period of 1985. The model was also used to simulate the stratification regime of the lake for the following year, in which environmental conditions were similar to 1985. For both years the model adequately depicted those stratification features previously identified as sensitive to acidification‐induced increases in transparency, including the thickness of the hypolimnion, the temperature of the hypolimnion, and the duration of stratification. Thus the model may facilitate assessments of the impact of acidification on the thermal characteristics of lakes. Model sensitivity analyses indicate that shallow lakes lose continuous summer stratification if they experience the increases in light penetration reportedly associated with acidification. Further, it was found that accurate specification of light attenuation coefficients a...

Effects of Neutralization and Addition of Brook Trout (Salvelinus fontinalis) on the Limnetic Zooplankton Communities of Two Acidic

The zooplankton communities in two acidified lakes in the Adirondack region of New York changed considerably following liming and the reintroduction of brook trout (Salvelinus fontinalis). Most rotifer taxa were greatly reduced in numbers within a week following base addition. Keratella taurocephala declined by orders of magnitude in both lakes. Rotifer species that replaced K. taurocephala were far less abundant. The crustacean communities were also affected by liming. Diaptomus minutus, the dominant in both lakes, declined following base addition. Longer-term population responses appeared to be related to the dynamics of the individual populations, and changes in predation pressure. Four additional crustacean species became prominent in the lakes after liming: the caldocerans Bosmina longirostris and Daphnia catawba in Cranberry Pond, and D. catawba and the cyclopoid copepod Cyclops scutifer in Woods Lake. Over the longer-term liming and the introduction of brook trout tended to have an overall positive effect on the zooplankton communities in the two lakes.

Chemical Response of Lakes Treated with CaCO3 to Reacidification

The reacidification of two lakes in the Adirondack region of New York treated by CaCO3 application was evaluated. Base treatment resulted in a very high immediate dissolution efficiency in both lakes (78–82%), increasing acid neutralizing capacity (ANC) to values of 450–550 μeq∙L−1. During the fall following manipulation, completely mixed water columns and elevated hydrologic inputs greatly facilitated reacidification, decreasing pH and diluting Ca2+ concentrations. Cranberry Pond effectively reacidified within 7 mo of treatment, while the ANC of Woods Lake decreased to near 0 μeq∙L−1 15 mo after application. In Cranberry Pond, pH values decreased below 5.5 resulting in transport of elevated concentrations of inorganic Al through the lake. Annual ANC budgets suggest that little CaCO3 penetrated to the sediments, limiting long-term release of ANC from sediment dissolution. Hydrolysis of Al, due to the elevated lake pH, served to consume ANC and there is evidence to indicate limited exchange of water column Ca2+ with sediments shortly after treatment followed by release of this Ca2+ during reacidification. However these processes did not significantly accelerate or attenuate the rate of reacidification. The rate of acidification could largely be explained by the flushing of ANC from the lakes by hydrologic inputs.

Short-Term Changes in the Chemistry of Trace Metals Following Calcium Carbonate Treatment of Acidic Lakes

Marked changes were evident in the concentrations of trace metals (aluminum, manganese, and zinc) following base application to two acidic lakes in the Adirondack region of New York. Immediately after calcite treatment, epilimnitic pH values increased above 9.0. This response coincided with a shift in the speciation of aluminum from acid-soluble to labile (inorganic) monomeric forms. Following the manipulation, pH values decreased below 8.0 as the epilimnion equilibrated with atmospheric CO2. Within 1–2 mo, aluminum, manganese, and zinc concentrations were greatly reduced, typically by an order of magnitude. The mechanism(s) for immobilization of trace metals following base treatment is not entirely clear. However, chemical equilibrium calculations suggest that at the higher pH resulting from base addition, lake water was oversaturated with readily forming aluminum and manganese minerals. Therefore, removal of these metals from the water column may have been due to direct precipitation. Solutions were highly undersaturated with zinc minerals, so zinc retention probably occurred by adsorption or coprecipitation reactions. Acidic Adirondack Lakes are generally net sinks for aluminum, and conservative with respect to transport of manganese and zinc. Base addition greatly enhanced retention of all three metals.

Short-Term Changes in the Acid/Base Chemistry of Two Acidic Lakes Following Calcium Carbonate Treatment

Woods Lake and Cranberry Pond, two chronically acidic lakes located in the Adirondack region of New York, USA, were intensively monitored following CaCO3 treatment in May 1985 to evaluate the mechanisms controlling short-term changes in water column chemistry. Immediately following base application (24 h), both lakes responded like systems closed to atmospheric CO2, because the dissolution of very small CaCO3 particles (median diameter 2 μm) exceeded the rate of atmospheric CO2 intrusion. Rapid dissolution of CaCO3 coupled with very low concentrations of dissolved inorganic carbon (DIC) prior to treatment, resulted in pH increases in the upper mixed waters from 4.9 to 9.4 in Woods Lake and from 4.6 to 9.1 in Cranberry Pond, as waters readily became saturated with CaCO3. pH increases were accompanied by stoichiometric increases in dissolved Ca2+, acid neutralizing capacity (ANC), and DIC. Following this initial perturbation, the upper mixed waters equilibrated with atmospheric CO2 over a 4 wk period, facilitating additional release of dissolved Ca2+ and ANC due to dissolution of suspended CaCO3. The amount of CaCO3 that dissolved during the 4 wk immediately following treatment, calculated from Ca2+ budgets, was very high; 86% in Woods Lake and 79% in Cranberry Pond.

Empirical Models of Fish Response to Lake Acidification

A large historical data set from the Adirondack region of New York was compiled to study the relationship between water chemistry variables associated with acid precipitation and the presence/absence of selected fish species. The data set was used to examine simple statistical models for fish presence/absence, as a function of the water chemistry variables, for brook trout (Salvelinus fontinalis), lake trout (Salvelinus namaycush), white sucker (Catostomus commersoni), and yellow perch (Perca flavescens). Of these models, only those for brook trout and lake trout were found to be acceptable based on statistical goodness-of-fit criteria; thus, parameters for models of these two species alone were estimated using maximum likelihood logistic regression. Candidate models for brook trout and lake trout were then examined, with particular consideration for the problems associated with model misspecification, errors-in-variables, and multicollinearity. For each of the two species, a model was recommended that may be used to predict the effect of changes in lake acidification on species presence/absence in lakes in the Adirondack region.

Longitudinal and temporal trends in the water chemistry of the North Branch of the Moose River

Surface water acidification is potentially a problem in regions with low ionic strength drainage waters. Atmospheric deposition of sulfuric acid has generally been implicated as the causative agent of this problem, although other sources of acidity may contribute. The Adirondack region of New York State is an area with “acid-sensitive” surface waters and an abundance of acidic lakes. The intent of this study was to evaluate the processes regulating the acid/base chemistry of a series of lakes draining a large heterogeneous watershed in the Adirondack region of New York. The study site, the North Branch of the Moose River, is heterogeneous in its soil and geological characteristics. This variability was reflected through differences in water chemistry that occurred within the basin. The northern headwaters generally drain subcatchments with shallow, acidic soils. The resulting water chemistry was acidic (equivalence of acidic anions exceeded equivalence of basic cations) with high concentrations of Al and dissolved organic carbon (DOC). As this water migrated through a large lake (Big Moose Lake) with a moderate hydrologic retention time (∼0.5 yr), considerable loss of DOC was evident. As acidic water was transported through the drainage area, it mixed with waters that were enriched in concentrations of basic cations from the eastern subbasins. As a result, there was a successive increase in the acid neutralizing capacity (ANC) and a decrease in Al concentrations as water migrated from the northern reaches to the outlet of the watershed. In addition to these general trends, short-term changes in water chemistry were evident. During low flow summer periods concentrations of basic cations were elevated, while concentrations of SO 4 2− and NO 3 − were relatively low. These conditions resulted in less acidic waters (higher ANC) with relatively low concentrations of Al. During high flow winter/spring conditions, elevated concentrations of SO 4 2− and NO 3 − were evident, while concentrations of basic cations were reduced resulting in low pH (low ANC) waters with high concentrations of Al. Variability in the processes regulating the pH buffering of waters was apparent through these short-term changes in water chemistry. In the northern subbasin short-term fluctuations in ANC were minimal because of the buffering of Al under low pH conditions. Seasonal changes in the ANC were more pronounced in the eastern subbasin because of the predominance of inorganic carbon buffering in the circumneutral pH waters. Lakes in the west-central Adirondacks have characteristically short hydraulic residence times and elevated nitric acid inputs. As a result these waters may be more susceptible to surface water acidification than other “acid-sensitive” lake districts in eastern North America. Given the apparent interregional differences, extrapolation of chemical trends in the Adirondacks to other areas may be tenuous.

Hydrogeologic controls of surface-water chemistry in the Adirondack region of New York State

Relationships between surface-water discharge, water chemistry, and watershed geology were investigated to evaluate factors affecting the sensitivity of drainage waters in the Adirondack region of New York to acidification by atmospheric deposition. Instantaneous discharge per unit area was derived from relationships between flow and staff-gage readings at 10 drainage basins throughout the region. The average chemical composition of the waters was assessed from monthly samples collected from July 1982 through July 1984. The ratio of flow at the 50-percent exceedence level to the flow at the 95-percent exceedence level of flow duration was negatively correlated with mean values of alkalinity or acid-neutralizing capacity (ANC), sum of basic cations (SBC), and dissolved silica, for basins containing predominantly aluminosilicate minerals and little or no carbonate-bearing minerals. Low ratios are indicative of systems in which flow is predominately derived from surface- and ground-water storage, whereas high ratios are characteristic of watersheds with variable flow that is largely derived from surface runoff. In an evaluation of two representative surface-water sites, concentrations of ANC, SBC, and dissolved silica, derived primarily from soil mineral weathering reactions. decreased with increasing flow. Furthermore, the ANC was highest at low flow when the percentage of streamflow derived from ground water was maximum. As flow increased, the ANC decreased because the contribution of dilute surface runoff and lateral flow through the shallow acidic soil horizons to total flow increased. Basins having relatively high ground-water contributions to total flow, in general, have large deposits of thick till or stratified drift. A major factor controlling the sensitivity of these streams and lakes to acidification is the relative contribution of ground water to total discharge.

Processes regulating temporal and longitudinal variations in the chemistry of a low-order woodland stream in the Adirondack region of New York

Watershed processes influence the acid neutralizing capacity of surface waters by mediating changes in concentration of ionic solutes. Acidification of surface waters by atmospheric deposition of mineral acids and the extent to which ecosystem transformations neutralize this acidity are of particular concern. Seasonal variations in flow paths of water through soil and biological processes result in short-term changes in chemistry that may be critical to surface water ecology. In this study, we assessed longitudinal and temporal variations in the chemistry of a low-order stream, Pancake-Hall Creek, located in the west-central Adirondack region of New York. By quantifying changes in ionic solute concentration (e.g. Ca2+, Aln+, SO2-, NO3 ) we were able to evaluate processes responsible for short-term fluctuations in acid/base chemistry. In the headwater sites, stream water was acidic; changes in pH, acid neutralizing capacity (ANC) and Al were primarily due to seasonal variations in basic cation and NO3 concentra- tions. At the downstream sites, water migrated through a large beaver impoundment and thick till resulting in higher pH, acid neutralizing capacity and basic cation concentrations, and lower concentrations of Al. Neutralization of acidity was particularly evident during the low flow summer period and coincided with retention of SO2- in the beaver impoundment. During the high flow non-summer (October to June) period, depressed pH and ANC, and elevated Al concentrations were observed in the downstream sites. Acidic conditions during the non-summer period were not due to the oxidation of reduced sulfur deposits (e.g. SO2- events) but rather the resumption of conservative S02- transport through the beaver im- poundment (e.g. minimal SO2- retention) coupled with increases in NO3

Lake-watershed acidification in the North Branch of the Moose River: Introduction

An integrated analysis of a terrestrial-aquatic ecosystem, the North Branch of the Moose River in the Adirondack region of New York, was conducted. This basin contains a large number of interconnected surface waters that exhibit marked gradients in pH and acid neutralizing capacity (ANC). As a result, the basin has been the focus of research activity, including the Regional Integrated Lake-Watershed Acidification Study (RILWAS). The objective of the current analysis was to use the North Branch of the Moose River as a case study to:

Concentration and flux of solutes from snow and forest floor during snowmelt in the West-Central Adirondack region of New York

Decreases in pH and increases in the concentration of Al and NO 3 − have been observed in surface waters draining acid-sensitive regions in the northeastern U.S. during spring snowmelt. To assess the source of this acidity, we evaluated solute concentrations in snowpack, and in meltwater collected from snow and forest floor lysimeters in the west-central Adirondack Mountains of New York during the spring snowmelt period, 29 March through 15 April 1984.

Manganese cycling in an acidic Adirondack lake

There is considerable interest in the chemistry of Mn in acidic waters because of its role in the generation of acid neutralizing capacity during reduction processes, as an adsorbent in element cycling, and as a potential toxicant to aquatic organisms. Temporal and spatial variations in the concentration of Mn were evident in acidic Dart's Lake (1.0–2.3 μmol l−1), located in the Adirondack Region of New York. Seasonal changes in pH and dissolved oxygen concentration had subtle effects on the chemistry and transport of Mn. Despite oversaturation with respect to the solubility of manganite during periods of stratification, vertical deposition of Mn was minimal. The conservative nature of Mn appears to be due to the acidic conditions in Dart's Lake.