Fish Health and Toxic Contaminants
Fish Health and Toxic Contaminants
Fish kills, skin lesions, and fish consumption advisories have raised concerns about the health of fish across the watershed. The USGS is working to identify the multiple factors that affect fisheries including toxic contaminants, disease, pathogens, and poor habitat conditions.
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Wastewater reuse may be detrimental to smallmouth bass abundance in the Shenandoah River Watershed
Issue: Municipal and industrial wastewater effluent is an important source of water for streams and rivers, especially during periods of low flow. The reuse of wastewater effluent may become even more important if climate change exacerbates low streamflow and drought conditions. However, wastewater effluent often contains chemicals that, when chronically present, can affect the health of aquatic...
Observed monitoring data and predictive modelling help understand ongoing and future vulnerability of Chesapeake Bay watershed stream fish communities to climate and land-use change
Issue: The Chesapeake Bay Watershed (CBW) is experiencing effects of climate (warming temperatures and shifting precipitation patterns) and land-use/land-cover (LULC; transition from forest or agriculture to developed lands) change, and these trends are likely to continue under future scenarios of warming and population growth. Stream biodiversity may be vulnerable to ongoing and future climate...
Communicating stream fish vulnerability to climate change
We will develop a vulnerability assessment R Shiny web application and present to stakeholders. The stakeholder feedback will be summarized into a one page ‘lessons learned’ document that will assist researchers in designing effective climate change visualizations and an R markdown ‘quick start’ guide on R Shiny applications.
Integrated Assessments of Potential Risks to Aquatic Organisms and Public Water Supply from Wastewater-Derived Chemical Mixtures in the Chesapeake Bay Watershed
Proper management of contaminants of emerging concern in the Chesapeake Bay region requires scientific efforts to understand the risk posed to aquatic resources from the “cocktail” of multiple contaminants that is often present. This research aims to assess the occurrence, sources, environmental impacts, biological effects, and the human health impacts of toxic contaminants in rivers.
A case study of temporal trends in risk factors associated with endocrine disruption in smallmouth bass
Issue The USGS has a long-term research effort that identified endocrine disruption in smallmouth bass (SMB) in the Chesapeake Bay watershed. Endocrine disruption can cause many changes in fish, including intersex characteristics where fish develop characteristics of the other sex, such as immature eggs forming in males. An overview by USGS of endocrine disruption in fish found the condition...
Review of Wildlife Health Outcomes and Potentially Toxic Algal Blooms in the Chesapeake Bay
Scientists provide resources that review algal toxin data, explore links between avian mortality and toxin exposure, and identify future research needs to predict algal toxin health hazards and risks for birds and other wildlife in the Chesapeake Bay.
Invasive Blue Catfish Science to Support Conservation and Fisheries Management
Dietary analyses, health, and reproduction of blue catfish in tributaries of the Chesapeake Bay inform ecosystem impacts and mitigation strategies for this aquatic nuisance species.
Tracking Status and Trends in Seven Key Indicators of River and Stream Condition in the Chesapeake Bay Watershed
Identifying and tracking the status of, and trends in, stream health within the Chesapeake Bay watershed is essential to understanding the past, present, and future trajectory of the watershed’s resources and ecological condition. A team of USGS ecosystem scientists is meeting this need with an initiative to track the status of, and trends in, key indicators of the health of non-tidal freshwater...
The statistical power to detect regional temporal trends in riverine contaminants in the Chesapeake Bay Watershed
Issue: Chemical contamination of riverine ecosystems is a global concern, with potentially negative effects for human and ecological health. Land management activities (e.g., Best Management Practices; BMPs) are an important tool that can be used to reduce point and non-point sources of pollution. The Chesapeake Bay Program (CBP) has goals for (1) reducing toxic contaminants and (2) reducing...
USGS Integrates Findings about Endocrine-Disrupting Compounds in the Chesapeake Watershed
Issue: Studies in the Chesapeake Bay Watershed have documented the exposure of fish to toxic contaminants including endocrine-disrupting compounds (EDCs) - compounds which can alter normal hormonal function in organisms. Given the importance of fisheries to the economic and environmental health of the Watershed, observed endocrine disruption and fish kills in the Watershed have raised public and...
Occurrence of toxic contaminant mixtures in surface water and groundwater in agricultural watersheds of the Chesapeake Bay
Issue The widespread use of pesticides and fertilizers, application of biosolids and manure, and large-scale animal feeding operations result in contaminant mixtures occurring in streams and rivers (figure 1). These nonpoint sources are affected by multiple processes (such as stream discharge, seasonality and management practices) that influence contaminant occurrence in surface and groundwater...
Bioaccumulation of Mercury in Fish Varied by Species and Location in the Chesapeake Bay Watershed—Summary of Existing Data and a Roadmap for Integrated Monitoring
Fish mercury data from State monitoring programs and research studies within the Chesapeake Bay were compiled and summarized to provide a comprehensive overview of the variation in fish mercury concentrations among species and habitats within the watershed. These data are put into context with existing health benchmarks for humans, birds, and fish. Scientists also provide a roadmap for an...