Howard A. Simonin

Lake variability: Key factors controlling mercury concentrations in New York State fish

A 4year study surveyed 131 lakes across New York State beginning in 2003 to improve our understanding of mercury and gather information from previously untested waters. Our study focused on largemouth and smallmouth bass, walleye and yellow perch, common piscivorous fish shown to accumulate high mercury concentrations and species important to local fisheries. Fish from Adirondack and Catskill Forest Preserve lakes generally had higher mercury concentrations than those from lakes in other areas of the state. Variability between nearby individual lakes was observed, and could be due to differences in water chemistry, lake productivity or the abundance of wetlands in the watershed. We found the following factors impact mercury bioaccumulation: fish length, lake pH, specific conductivity, chlorophyll a, mercury concentration in the water, presence of an outlet dam and amount of contiguous wetlands.

In situ toxicity tests of fishes in acid waters

Toxicity of waters within the North Branch of the Moose River to various life stages of lake trout (Salvelinus namaycush), brook trout (Salvelinus fontinalis), creek chub (Semotilus atromaculatus), and blacknose dace (Rhinichthys atratulus) were examined in situ. Study sites were selected that were expected to range from toxic to favourable water quality. For example, pH varied from 4.25 to 7.17, inorganic monomeric Al ranged from ND (< 0.01 mg/l) to 0.40 mg/l, and Ca, from 0.41 to 4.27 mg/l.Toxicity tests were conducted at times when the life stages would naturally occur in these waters and were continued until a range of mortality was observed at the various sites. These experiments suggested that the extent of the drainage system that is toxic to fish increases during snowmelt and major runoff events. Summer base flow water quality was generally the least toxic.Critical life stages were upon hatching and as early feeding fry. In general, young of the year fish were the most tolerant life stage tested. Yearling and adult fish, however, were very sensitive. Blacknose dace were the most sensitive fish of the four species tested, and brook trout were the most tolerant.Hydrogen ion (H+) concentration was the most toxic variable in the majority of tests. Inorganic monomeric Al was the most toxic in several, and the combination of H+ and Al seemed to cause increased toxicity in many instances. A three-variable model employing hours of exposure, H+ concentration, and inorganic monomeric Al predicted mortality quite well. A simple two-variable model using H+ and color was nearly as good (R2 from 0.49 to 0.94).Documented differences in toxicity among sites and species agreed with observed patterns of fish distribution. These in situ results indicated that laboratory estimates of safe levels of pH and concentrations of Al can result in mortality of fishes in surface waters subject to acidification.

Chronic and episodic acidification of Adirondack streams from acid rain in 2003-2005.

Limited information is available on streams in the Adirondack region of New York, although streams are more prone to acidification than the more studied Adirondack lakes. A stream assessment was therefore undertaken in the Oswegatchie and Black River drainages; an area of 4585 km(2) in the western part of the Adirondack region. Acidification was evaluated with the newly developed base-cation surplus (BCS) and the conventional acid-neutralizing capacity by Gran titration (ANC(G)). During the survey when stream water was most acidic (March 2004), 105 of 188 streams (56%) were acidified based on the criterion of BCS < 0 microeq L(-1), whereas 29% were acidified based on an ANC(G) value < 0 microeq L(-1). During the survey when stream water was least acidic (August 2003), 15 of 129 streams (12%) were acidified based on the criterion of BCS < 0 microeq L(-1), whereas 5% were acidified based on ANC(G) value < 0 microeq L(-1). The contribution of acidic deposition to stream acidification was greater than that of strongly acidic organic acids in each of the surveys by factors ranging from approximately 2 to 5, but was greatest during spring snowmelt and least during elevated base flow in August. During snowmelt, the percentage attributable to acidic deposition was 81%, whereas during the October 2003 survey, when dissolved organic carbon (DOC) concentrations were highest, this percentage was 66%. The total length of stream reaches estimated to be prone to acidification was 718 km out of a total of 1237 km of stream reaches that were assessed.

Changes in the chemistry of acidified Adirondack streams from the early 1980s to 2008.

Lakes in the Adirondack region of New York have partially recovered in response to declining deposition, but information on stream recovery is limited. Here we report results of Adirondack stream monitoring from the early 1980s to 2008. Despite a 50% reduction in atmospheric deposition of sulfur, overall increases in pH of only 0.28 and ANC of 13 μeq L(-1) were observed in 12 streams over 23 years, although greater changes did occur in streams with lower initial ANC, as expected. In the North Tributary of Buck Creek with high dissolved organic carbon (DOC) concentrations, SO(4)(2-) concentrations decreased from 1999 to 2008 at a rate of 2.0 μmol L(-1) y(-1), whereas in the neighboring South Tributary with low DOC concentrations, the decrease was only 0.73 μmol L(-1) y(-1). Ca(2+) leaching decreased in the North Tributary due to the SO(4)(2-) decrease, but this was partially offset by an increase in Ca(2+) leaching from increased DOC concentrations.

THE TOXICITY OF DIQUAT, ENDOTHALL, AND FLURIDONE TO THE EARLY LIFE STAGES OF FISH

ABSTRACT While most aquatic herbicides have undergone some toxicity testing for effects on non-target aquatic organisms, little of this testing has been conducted on early life stages of gamefish found in lakes undergoing treatment. Commercial formulations of diquat, endothall, and fluridone were selected for acute toxicity testing using very early life stages of walleye (Stizostedion vitreum), largemouth bass (Micropterus salmoides), and smallmouth bass (Micropterus dolomieu). In addition, the rates of diquat photodegradation and uptake by sediment were determined. These results were used to predict diquat concentrations in lakes of various depths. The results of the toxicity tests were compared to the predicted concentrations. Diquat, with 96-h LCSOs of 0.74–4.9 mg/L, was more toxic to these early life stages than endothall or fluridone, with 96-h LC50s of 16–130 mg/L and 1.8–13 mg/L respectively. The LC50s for endothall and fluridone were at least one order of magnitude greater than the labeled applica...

Mercury and other air toxics in the Adirondack region of New York

Abstract The Clean Air Act Amendments of 1990 identified nearly 200 air toxics, or hazardous air pollutants. These include pesticides, industrial chemicals, metals, chlorinated and hydrocarbon solvents, PCBs, and combustion by-products. Although the Adirondack region of New York is remote from most sources of air toxics, the region has been impacted as a result of atmospheric deposition of certain chemicals. Mercury is the primary air toxic of concern for the Adirondack region. Acidification of the Adirondacks has made mercury and other metals more mobile, and mercury in particular has bioaccumulated in fish from acidic waters. Large, older age, piscivorous fish such as bass, walleye, large yellow perch and northern pike accumulate the highest mercury concentrations. Low concentrations of mercury are generally observed in trout species, sunfish and bullhead. Common loons are at risk due to the mercury levels in the fish they consume. Loons which nest on acidic waters in Wisconsin have reduced fledging rates compared with loons nesting on neutral lakes. Mink and otter accumulate higher levels of mercury than the fish which they eat. Emissions of air toxics are being reduced as a result of recent control programs, and it is hoped that these reductions will lead to lower concentrations of toxic chemicals in Adirondack biota.

Have Adirondack Stream Fish Populations Changed in Response to Decreases in Sulfate Deposition

Abstract Fish populations in 36 Adirondack headwater streams were surveyed by electrofishing in fall 1979 and 1999; water chemistry samples were collected during spring 1980 and 2000. The surveys were designed to evaluate impacts of acidity on stream fish populations and also to document any changes that had occurred between the two studies. The acid-neutralizing capacity and pH of the streams were not significantly different between 1980 and 2000, although in a different grouping of 37 Adirondack streams, calcium levels were significantly lower in spring 2000 than in spring 1982. More fish and fish species were collected in 1999 than 1979. However, because changes occurred in streams with relatively high pH (>6.0) as well as in low-pH streams, increases in fish caught may have been partly the result of improved electrofishing efficiency in 1999. In both 1999 and 1979, streams with spring pH less than 5.0 supported fewer fish, fewer salmonids, and fewer fish species than streams with higher pH. No young-o...

Evaluation of Cutrine for Use in Fish Culture

Abstract Laboratory and field tests were conducted with Cutrine, a chelated copper algicide registered for use in fish hatcheries. The 96-h LC50 for fingerling largemouth bass (Micropterus salmoides) was found to be 70 µL/L Cutrine (6.4 mg/L Cu) at 21.1°C and 2.3 µL/L (0.21 mg/L Cu) for fathead minnows (Pimephales promelas) at 18.3°C. When Cutrine was applied at a rate of 2.3 µL/L (0.75 gal/A-ft) to half of a rearing pond for fathead minnows, the amount of filamentous algae was substantially reduced. Caged largemouth bass and fathead minnows showed less than 10% mortality in the treated area of the pond.

Wildlife Criterion Value for the Common Loon (Gavia immer) in the Adirondack Park, New York, USA

Abstract. Estimates of wildlife population viability through measurements of contaminant stressors, such as water mercury concentrations, were modified with variables specific to New York’s Adirondack Park to develop a wildlife criterion value for the Common Loon (Gavia immer). Biotic and abiotic samples were collected for mercury analysis on 44 Adirondack lakes over a 2-year period (2003 to 2004). From 1998 to 2007, Common Loon blood samples were collected for mercury analysis from the 44 lakes, loon feather samples from 40 lakes, and nonviable eggs from 29 lakes. It was determined that 2.00 ng Hg/L or less in the water was small enough to prevent male Adirondack Common Loons from accumulating mercury in levels high enough to impact reproductive success and behavior, while a water sample of 1.69 ng Hg/L or less was small enough to not cause impacts to female Common Loons. These wildlife criterion values are greater than the wildlife criterion value of 1.30 ng Hg/L applied to avian species by the Great Lakes Water Quality Initiative. The Common Loon-based wildlife criterion value provides a valuable estimate of the mercury thresholds associated with biotic impacts due to mercury contamination in aquatic ecosystems, enabling legislators to integrate these standards into policies that better protect environmental quality. Based on the water samples collected, it was estimated that the wildlife criterion value accurately predicted the protection of 61% of female and 73% of male Adirondack loons. More rigorous sampling of the abiotic compartment over a wider temporal and spatial scale is necessary to fully understand how water quality parameters relate to Common Loon reproductive success.