Fish Health and Toxic Contaminants

The findings of this study show that salinity is elevated above background levels throughout most freshwater streams within the Chesapeake Bay watershed. This information can help prioritize salt management strategies for local streams and rivers.

USGS is studying the spread and effects of “blotchy bass syndrome” on black basses ( Micropterus spp). USGS and state agencies have partnered with citizen scientists and recreational organizations to create a continent-wide biosurveillance network to monitor the syndrome.

Wastewater treatment plant discharges can be a source of organic contaminants, including pesticides, to rivers. Pesticide concentrations were predicted based on wastewater percentages in stream water using a modeling tool, and verified with measured concentrations to identify other potential landscape sources.

Per- and polyfluoroalkyl substances (PFAS) are a large group of chemicals that have been recognized as concerns for both human and ecosystem health. There is a need to understand the effects of PFAS on fish health and populations.

Contaminants associated with agricultural and developed land uses may negatively affect SMB health and disease resistance in the Susquehanna River watershed.

USGS is helping with the design of a population survey and developing mathematical models to assess potential activities to manage the population of invasive blue catfish ( Ictalurus furcatus) in the Chesapeake Bay. This research will help managers determine the cost and feasibility of approaches to control this invasive species.

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...

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...

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.

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.

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...

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.