Langwig K.E.,Boston University |
Langwig K.E.,University of California at Santa Cruz |
Frick W.F.,University of California at Santa Cruz |
Bried J.T.,Oklahoma State University |
And 3 more authors.
Ecology Letters | Year: 2012
Disease has caused striking declines in wildlife and threatens numerous species with extinction. Theory suggests that the ecology and density-dependence of transmission dynamics can determine the probability of disease-caused extinction, but few empirical studies have simultaneously examined multiple factors influencing disease impact. We show, in hibernating bats infected with Geomyces destructans, that impacts of disease on solitary species were lower in smaller populations, whereas in socially gregarious species declines were equally severe in populations spanning four orders of magnitude. However, as these gregarious species declined, we observed decreases in social group size that reduced the likelihood of extinction. In addition, disease impacts in these species increased with humidity and temperature such that the coldest and driest roosts provided initial refuge from disease. These results expand our theoretical framework and provide an empirical basis for determining which host species are likely to be driven extinct while management action is still possible. Copyright © 2012 Blackwell Publishing Ltd/CNRS159 September 2012 10.1111/j.1461-0248.2012.01829.x Letter Letters © 2012 Blackwell Publishing Ltd/CNRS.
Rozell D.,NY Environmental Conservation
Journal of Environmental Engineering | Year: 2010
An arsenic filtration experiment using iron oxide coated sand was modeled using the USGS geochemical program PHREEQC. Despite some uncertainty regarding the initial conditions of the groundwater and the simplicity of the model, it replicated the experimental results within 10%. The original experiment filtered 165 bed volumes to concentrations less than 0.01 mg/L As and approximately 210 bed volumes to 0.05 mg/L As. The model filtered 168 bed volumes to 0.01 mg/L As and 228 bed volumes to 0.05 mg/L. © 2010 ASCE.
Rozell D.J.,NY Environmental Conservation |
Wong T.,State University of New York at Stony Brook
Hydrogeology Journal | Year: 2010
Rising sea levels due to climate change are expected to negatively impact the fresh-water resources of small islands. The effects of climate change on Shelter Island, New York State (USA), a small sandy island, were investigated using a variable-density transient groundwater flow model. Predictions for changes in precipitation and sea-level rise over the next century from the Intergovernmental Panel on Climate Change 2007 report were used to create two future climate scenarios. In the scenario most favorable to fresh groundwater retention, consisting of a 15% precipitation increase and 0. 18-m sea-level rise, the result was a 23-m seaward movement of the fresh-water/salt-water interface, a 0. 27-m water-table rise, and a 3% increase in the fresh-water lens volume. In the scenario supposedly least favorable to groundwater retention, consisting of a 2% precipitation decrease and 0. 61-m sea-level rise, the result was a 16-m landward movement of the fresh-water/salt-water interface, a 0. 59-m water-table rise, and a 1% increase in lens volume. The unexpected groundwater-volume increase under unfavorable climate change conditions was best explained by a clay layer under the island that restricts the maximum depth of the aquifer and allows for an increase in fresh-water lens volume when the water table rises. © 2010 Springer-Verlag.
Aleksic N.,NY Environmental Conservation |
Dukett J.E.,Adirondack Lakes Survey Corporation
Atmospheric Research | Year: 2010
Within non-precipitating clouds, total ionic content (TIC) of cloud droplets decreases with increasing liquid water content (LWC). However, this is not a simple inverse relationship. Instead, TIC has an exponential distribution with a parameter that is dependent on LWC. We demonstrate this finding using a long-term monitoring record (1994-2006) of cloud water chemistry measurements collected at the summit of Whiteface Mountain, NY. © 2010 Elsevier B.V.
McKenna Jr. J.E.,U.S. Geological Survey |
Carlson D.M.,NY Environmental Conservation |
Payne-Wynne M.L.,New York University
Diversity and Distributions | Year: 2013
Aim: Rare aquatic species are a substantial component of biodiversity, and their conservation is a major objective of many management plans. However, they are difficult to assess, and their optimal habitats are often poorly known. Methods to effectively predict the likely locations of suitable rare aquatic species habitats are needed. We combine two modelling approaches to predict occurrence and general abundance of several rare fish species. Location: Allegheny watershed of western New York State (USA) Methods: Our method used two empirical neural network modelling approaches (species specific and assemblage based) to predict stream-by-stream occurrence and general abundance of rare darters, based on broad-scale habitat conditions. Species-specific models were developed for longhead darter (Percina macrocephala), spotted darter (Etheostoma maculatum) and variegate darter (Etheostoma variatum) in the Allegheny drainage. An additional model predicted the type of rare darter-containing assemblage expected in each stream reach. Predictions from both models were then combined inclusively and exclusively and compared with additional independent data. Results: Example rare darter predictions demonstrate the method's effectiveness. Models performed well (R2 ≥ 0.79), identified where suitable darter habitat was most likely to occur, and predictions matched well to those of collection sites. Additional independent data showed that the most conservative (exclusive) model slightly underestimated the distributions of these rare darters or predictions were displaced by one stream reach, suggesting that new darter habitat types were detected in the later collections. Main conclusions: Broad-scale habitat variables can be used to effectively identify rare species' habitats. Combining species-specific and assemblage-based models enhances our ability to make use of the sparse data on rare species and to identify habitat units most likely and least likely to support those species. This hybrid approach may assist managers with the prioritization of habitats to be examined or conserved for rare species. © 2013 John Wiley & Sons Ltd.
Henry R.F.,NY Environmental Conservation
Atmospheric Environment | Year: 2013
Analysis of PAMS (Photochemical Assessment Monitoring Stations) data at several coastal sites reveals large weekday/weekend differences in gasoline related hydrocarbons. Elevated concentrations of gasoline related constituents, including alkanes, alkenes, and aromatics, are observed on weekends at the PAMS monitors at Sherwood Island State Park in Westport, CT and at Newbury, MA. An analysis of the ratio of the concentrations of 2,3-dimethylbutane to 2,2-dimethylbutane indicates these compounds are freshly emitted, and an investigation in conjunction with wind data shows that the elevated concentrations are associated primarily with onshore winds. These elevated concentrations are most likely due to weekend recreational boating. © 2013 Elsevier Ltd.
Skinner L.C.,NY Environmental Conservation
Environmental Pollution | Year: 2011
PCBs (as Aroclor concentrations) have been extensively examined in fish along the Hudson River, but other xenobiotic chemicals in fish have had limited assessment. This study determined concentrations and congener distributions of polybrominated diphenyl ethers (PBDEs), polybrominated and polychlorinated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs and PCDD/Fs), and polychlorinated biphenyls (PCBs) in smallmouth bass and striped bass taken from a 385 km reach of the Hudson River. Concentrations of PBDEs and PCBs in smallmouth bass, and PCBs in striped bass, were positively related to human uses of the compounds in the basin. Generally low levels of PCDD/Fs were found. One striped bass, however, contained elevated 2,3,7,8-TCDD, indicating exposure to a known source in the adjacent Newark Bay-Passaic River basin. PBDDs were generally below detection. PBDFs were present in four of 18 smallmouth bass, but were not detected in striped bass. Dioxin-like PCBs contribute most to 2,3,7,8-TCDD toxic equivalents in 29 of 30 samples. © 2010 Published by Elsevier Ltd.
Mayack D.T.,NY Environmental Conservation
Environmental Monitoring and Assessment | Year: 2012
Many non-linear processes link atmospheric emissions to the bioavailability of metals; consequently, the monitoring of metals in ecosystem components is required to model their ecodynamics. American mink (Neovison vison) and river otter (Lontra canadensis) have the potential to serve as an upper-level-consumer component in monitoring metals bioavailability. However, the relationship of bioaccumulated metals to various environmental factors has not been explored nor have the effects of demographic factors been resolved. To address these limitations, mink and otter, collected throughout New York State during 1998-2002, were analyzed for hepatic concentrations of total mercury (Hg), cadmium (Cd), and lead (Pb). Relationships were investigated between metals concentrations and landscape-level factors (physiographic zone, hydrologic unit, and elevation) and demographic factors (gender and age). Considerable variation in Hg and Cd concentrations was observed relative to both physiographic zone and hydrologic unit for both species. In contrast with Hg, Cd concentration increased predictably with increasing elevation. Mercury concentrations were greater, but for Cd less, in otter than mink. Lead concentrations showed little landscape heterogeneity and were independent of elevation. Age-related bioaccumulation was evident for Hg and Cd, but not for Pb, in both species. Mercury and Cd concentrations were greater in female than male mink; however, Pb concentrations were greater in males than females. Inverse relationships of relative growth (weight/length) to metals concentrations explained gender differences in Hg and Cd in mink. For otter, no gender-related differences in metals concentrations were apparent. The suitability of mink and otter for monitoring programs is discussed. © Springer Science+Business Media B.V. 2011.
Smith A.J.,NY Environmental Conservation |
Tran C.P.,New England Interstate Water Pollution Control Commission |
Tran C.P.,New York University
Journal of the North American Benthological Society | Year: 2010
Cultural eutrophication of surface waters has become a major source of water-quality impairment throughout the US. In response, the US Environmental Protection Agency (USEPA) has devised a national strategy for the development of regional nutrient criteria. Our study is part of New York State's effort to revise its narrative nutrient standard for N and P and is based on the USEPA's recommended weight-of-evidence approach. The objective of our investigation was to identify nutrient thresholds based on a final weighted average of results from percentile analysis, nonparametric deviance reduction (changepoint), and cluster analysis. The thresholds were determined from shifts in biological community structure (benthic macroinvertebrate and diatom) related to water-column nutrient data from 40 large river sites throughout New York State. USEPA's percentile analysis yielded possible criteria of 0.023 mg total P (TP)/L, 0.51 mg total N (TN)/L, 0.16 mg NO3-N /L, and 2.4 mg chlorophyll a (chl a)/m3. Threshold responses in benthic macroinvertebrate metrics at the 50th percentile occurred at concentrations between 0.009 and 0.07 mg TP/L, 0.41 and 1.2 mg TN/L, 0.18 and 0.55 mg NO3-N/L, and 2.1 mg chl a/m3. Cluster analysis yielded 3 groups of sites based on macroinvertebrate and diatom taxa. The median nutrient values of the medium-nutrient-condition site clusters were used to set criteria for TP and TN. For site clusters based on macroinvertebrate data these values were 0.037 mg TP/L and 0.68 mg TN/L. For clusters based on diatom data these were 0.037 mg TP/L and 0.78 mg TN/L. Based on the weight-of-evidence approach and results from all 3 methods, the proposed guidance values for nutrients in large rivers are 0.03 mg TP/L, 0.7 mg TN/L, 0.3 mg NO 3-N/L, and 2.2 mg chl a/m3. These values are similar to those derived by others and provide meaningful nutrient endpoints that would be protective of aquatic life in large rivers. © 2010 The North American Benthological Society.
Kapuscinski K.L.,New York University |
Farrell J.M.,New York University |
Wilkinson M.A.,NY Environmental Conservation
Journal of Great Lakes Research | Year: 2014
We review the history of muskellunge management and describe population and fishery responses to management actions. Stocking of muskellunge in the Niagara River occurred sporadically from 1941 to 1974 when angler harvest was common. Since the late 1970s, managers have enacted increasingly restrictive minimum length limits and anglers adopted a catch-and-release ethic. Despite these efforts, angler catches declined sharply after 1991 in Buffalo Harbor and 1984 in the upper Niagara River; catch rates rebounded after 2006 in the Niagara River, but remain near all-time lows in Buffalo Harbor. In addition, mean catch rates of young-of-the-year (YOY) in fall electrofishing surveys declined from 3.3/h in 1992-1993 to 1.7/h in 2006-2009 in Buffalo Harbor and 11.0/h in 1992-1994 to 5.4/h in 2006-2009 in the Niagara River. Several ecosystem changes occurred that likely contributed to reductions in muskellunge populations, but comprehensive monitoring programs were not in place to quantify these effects. Recent seining surveys show YOY muskellunge production during 2007-2011 was highly variable among index sites (within years) and years, but catch per unit effort was 5.3 times higher at Niagara River sites than Buffalo Harbor sites; catch per unit effort of all fishes was 9.5 times higher in the upper Niagara River than Buffalo Harbor. Both areas are in need of habitat restoration, but habitats in Buffalo Harbor appear especially poor for nearshore fishes. Uncertainty about which factors led to declines in angler catches of muskellunge and YOY production demonstrates the need for a comprehensive monitoring program and formal muskellunge management plan. © 2012 International Association for Great Lakes Research.