Geology topics

Dylan R. Winterhalter

Publications and source records attributed to Dylan R. Winterhalter.

6 recordsLinked to original sources

USGS2023

Use of environmental DNA to assess American Eel distribution, abundance, and barriers in a river-canal system

Objective: The American Eel Anguilla rostrata historically was one of the most common fish species in Atlantic coast watersheds, but extensive dam construction and other factors caused a widespread population decline. One of the watersheds where American Eels have declined considerably is the Mohawk River in eastern and central New York. Recent attempts to characterize the distribution and abundance of American Eels in this watershed have been ineffective, and the extent to which a series of locks and dams on the Hudson River and lower Mohawk River limits use of the watershed is unclear. Methods: We developed a model between environmental DNA (eDNA) quantity and American Eel abundance in the Hudson River watershed in which the DNA concentration in water samples explained up to 65% of the variability in eel density and 56% of the variability in eel biomass. We then used this relationship to interpret eDNA data collected twice from 36 sites across the Mohawk River watershed in 2021 and make inferences about the distribution and abundance of American Eels. Result: American Eel DNA was detected almost exclusively in the downstream-most 4 km of the Mohawk River within a series of barriers. The concentration of DNA was reduced by approximately 80% across each successive upstream barrier before becoming too low to detect consistently. Our data suggest that eel population density was high in the Hudson River estuary and declined rapidly in the lower Mohawk River, and the species was nearly absent or undetectable in the Mohawk River and its tributaries upstream of the Crescent Dam and the Waterford Flight of Locks. Conclusion: Barriers appear to be largely restricting American Eels from using over 99% of the Mohawk River watershed. Therefore, improvements in fish passage at dams and hydroelectric facilities in the region could help the American Eel to regain access to this part of its native range.

New York↗

USGS2023

Survey of fish communities in tributaries to the Mohawk River, New York, 2019

Fish communities of the Mohawk River and associated sections of the New York State Canal System have been well documented but little information is available regarding the status of fish communities in the extensive network of tributaries that feed the Mohawk River. This lack of information is problematic because changes in species distributions or general ecosystem health may go unnoticed in the absence of baseline data. The need for baseline information has been made particularly urgent by the recent establishment of a high-profile invasive fish species in the mainstem of the Mohawk River, the round goby ( Neogobius melanostomus ). Round goby can adversely affect aquatic ecosystems in numerous ways and are able to colonize streams in addition to large rivers and lakes. This potential threat to the aquatic ecosystem, therefore, has created an urgent need to quantify the distribution and abundance of fish species inhabiting tributaries to the Mohawk River before round goby can begin colonizing these habitats. In response, the U.S. Geological Survey and the Mohawk River Basin Program of the New York State Department of Environmental Conservation initiated a study in 2019 to collect quantitative information on fish communities and stream habitats in tributaries to the Mohawk River that could be used in the future to determine the effects of round goby on local fish assemblages and identify substrate and other habitat characteristics that facilitate or inhibit colonization by round goby. Fish communities were surveyed at 20 sites on tributaries to the Mohawk River during summer 2019, using three-pass depletion backpack electrofishing surveys. The resulting data were used to produce quantitative estimates of fish population density and biomass for all species at each site. A total of 11,794 individual fish and 37 species were captured during the 20 surveys. Longnose dace ( Rhinichthys cataractae ), white sucker ( Catostomus commersonii ), blacknose dace ( Rhinichthys atratulus ), fantail darter ( Etheostoma flabellare ), and creek chub ( Semotilus atromaculatus ) were the most frequently encountered species, occurring at 18, 18, 17, 17, and 16 of the 20 sites, respectively. Six darter species, small bottom-dwelling fish that are highly vulnerable to displacement by round goby, were captured during the surveys, and at least one darter species was captured at all but one of the sites. Round goby were only captured at one site, Ninemile Creek near Rome, New York, where they occurred at a low density. Overall, the results indicated that round goby had not extensively colonized tributaries to the Mohawk River as of 2019, and the suite of data collected in this project should serve as a valuable baseline for future assessments of the effects of round goby and other stressors on aquatic ecosystems.

New York↗

USGS2022

Condition of resident fish communities in the Eighteenmile Creek Area of Concern, New York

The lower 3.5 km of Eighteenmile Creek, a tributary to Lake Ontario in New York, was designated as an Area of Concern (AOC) in 1985 under the Great Lakes Water Quality Agreement due to extensive contamination of bed sediments by polychlorinated biphenyls (PCBs) and other toxicants. Five beneficial use impairments (BUIs) have been identified in this AOC, including degraded fish and wildlife populations. We surveyed fish communities in the Eighteenmile Creek AOC and in a comparable section of a nearby reference stream (Oak Orchard Creek) during June 2019 to infer whether legacy contaminants are currently impairing fish communities in the AOC to an extent that they differ from the regional reference condition. Estimates of community abundance, biomass, diversity, and fish condition from each system were compared using a noninferiority testing framework. Biomass, diversity, and fish condition in the Eighteenmile Creek AOC were similar or superior to that in Oak Orchard Creek, while abundance was 20% lower in the AOC. These findings and those of a 2007 sampling effort suggest that fish communities in the Eighteenmile Creek AOC are not impaired despite recent studies indicating that PCBs are bioaccumulating in fish tissues at 1–2 orders of magnitude above background levels. Future assessments in the Eighteenmile Creek AOC might focus on the condition of benthic macroinvertebrate communities and potential toxicity of local contaminants to piscivorous wildlife in order to fully address the remaining aspects of the fish and wildlife populations beneficial use impairment.

New York↗

USGS2021

Survey of fish assemblages in the upper Neversink River and upper Rondout Creek, New York, 2017–19

Streams in the Catskill Mountains region of New York provide many important ecological and economic services, including recreational angling and serving as a drinking water supply to New York City. Many streams in this region were adversely affected by acid deposition during the late 20th century, impairing water quality and aquatic ecosystems. More recently, the level of acid deposition has declined while changes in climate have become more pronounced. As a result, biological and chemical data are needed to determine the current condition of stream ecosystems in the Catskill Mountains region. The U.S. Geological Survey, in cooperation with the Rondout Neversink Stream Program, surveyed fish communities and water chemistry annually between 2017 and 2019 at 23 sites in the upper Neversink River and upper Rondout Creek watersheds to compile a contemporary baseline dataset and assess potential biological recovery from reduced acidification. The resulting data indicated that brook trout ( Salvelinus fontinalis ) were present at every study site, although slimy sculpin ( Cottus cognatus ) was the most abundant species at most sites. Stream pH ranged from 4.8 to 7.0 across all sites and generally increased from upstream to downstream. Similarly, the number of species present and the ratio of brown trout ( Salmo trutta ) to brook trout increased at sites in each subwatershed from upstream to downstream.

New York↗

USGS2021

Eastward expansion of Round Goby in New York: Assessment of detection methods and current range

The Round Goby Neogobius melanostomus has spread rapidly around the Great Lakes region since its introduction to North America in 1990. In 2014, a specimen was captured in the New York State Canal System west of Utica, prompting concerns that Round Goby would soon reach the ecologically and economically valuable watersheds of Lake Champlain and the Hudson River estuary. The establishment of Round Goby populations elsewhere has been linked to a number of negative ecological consequences, yet methods for monitoring the invasion front of this species remain limited. The objectives of this study were to assess the current distribution of Round Goby in central New York and to determine the most effective methods for monitoring the invasion front. This was achieved by concurrently using benthic trawling, seining, minnow traps, and environmental DNA (eDNA) twice annually from 2016 to 2019 at 12 sites on the canal system between Oneida Lake and the Hudson River. Of the three traditional gear types, benthic trawling was the most effective method and captured Round Goby as far east as Utica by 2019. This finding suggests only minimal eastward expansion of Round Goby occurred between 2014 and 2019. Round Goby DNA was detected in water samples during all surveys in which individuals were captured with trawling, and the estimated concentration of DNA explained 69% of the variability in trawl catch. At multiple study sites, Round Goby DNA was identified during consecutive surveys before Round Goby were first captured with trawling. This suggests that in lotic waters, eDNA has the potential to forecast or serve as a sentinel for the expansion of Round Goby to new locations. Our results demonstrate the importance of using eDNA in a repeated sampling framework and supplementing eDNA sampling with some level of effort with traditional sampling methods.

Great Lakes↗

USGS2021

Biological and chemical recovery of acidified Catskill Mountain streams in response to the Clean Air Act Amendments of 1990

Decades of acidic deposition have adversely affected aquatic and terrestrial ecosystems in acid-sensitive watersheds in parts of the eastern United States. The national Acid Rain Program (Title IV of the 1990 Clean Air Act Amendments - CAAA) helped reduce emissions of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ) and resulted in sharp decreases in the acidity of atmospheric deposition. The decrease in acidic deposition produced a steady decline in the acidity of streams in many poorly buffered waters across the western Adirondacks and parts of the Catskill Mountains of New York. Until recently, however, there has been little evidence of biological recovery in most acid-sensitive streams in both regions. Long-term deposition and stream-chemistry records and fish-community data from quantitative surveys done during 1991–93 and again during 2012–19 at 13 sites in the upper Neversink River and its tributaries were evaluated to determine if chemical and biological recovery were evident in this Catskill Mountain watershed and if they could be linked to regional declines in acidic deposition. Between 1991 and 2019, large decreases in sulfate and nitrate deposition in the basin mirrored declines in total nationwide SO 2 and NO x emissions. There were corresponding decreases in sulfate and nitrate concentrations in deposition at a National Trends Network station at Frost Valley (NY68) and coincident declines in sulfate concentrations at four long-term monitoring sites in the Neversink River watershed. Mean acid neutralizing capacity and pH increased and inorganic aluminum (Al i ) concentrations from routine summertime samples decreased significantly at most moderately to severely acidified sites between the two study periods. Richness, density, and biomass of fish communities increased at most sites, while the density and biomass of brook trout Salvelinus fontinalis populations increased at fewer sites that were undergoing chemical recovery. Although recovery is far from complete, trends in deposition chemistry, water quality, and fish assemblages in streams of the upper Neversink watershed indicate that the 1990 CAAA is having positive impacts on aquatic ecosystems in the Catskill Mountain region, New York.

New York↗