Scientists have found intersex fish in three Pennsylvania river basins, indicating hormone-disrupting chemicals are more widespread in the Chesapeake Bay watershed than once thought.
Image courtesy RTD Photography/Flickr
Intersex conditions occur when pesticides, pharmaceuticals or other chemicals disrupt the hormonal systems of an animal, leading to the presence of both male and female characteristics. The presence of intersex conditions in fish, frogs and other species is linked to land use, as the chemicals that lead to these conditions often enter rivers and streams through agricultural runoff or wastewater.
Previous samplings of fish in the region have found intersex conditions in the Potomac, Shenandoah and Susquehanna rivers, as well as lakes and ponds on the Delmarva Peninsula. On samplings conducted at 16 sites between 2007 and 2010, researchers with the U.S. Geological Survey (USGS) found intersex fish in the Susquehanna, Delaware and Ohio river basins.
According to the USGS, freshwater fish called white suckers from sample sites in the Delaware and Susquehanna river basins had a yolk precursor in their blood. Male smallmouth bass from all sample sites had immature eggs in their testes. The prevalence of intersex fish was highest in the Susquehanna river basin, which researchers attribute to the higher rate of farms—and related herbicides, pesticides and hormone-containing manure—in the area. While scientists found no relationship between the number of wastewater treatment plants in an area and the prevalence of immature eggs in fish, the severity of intersex conditions did rise at sites downstream from wastewater discharge points.
“The sources of estrogenic chemicals are most likely complex mixtures from both agricultural sources, such as animal wastes, pesticides and herbicides, and human sources from wastewater treatment plant effluent and other sewer discharges,” said fish biologist Vicki Blazer in a media release.
Over the Chesapeake Bay Program’s long history, its leaders have learned that collaboration is key to restoration success. In June, the governors of Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia, the mayor of the District of Columbia, the administrator of the U.S. Environmental Protection Agency (EPA) and the chair of the Chesapeake Bay Commission came together to sign the Chesapeake Bay Watershed Agreement. Written with input from individuals, organizations and other partners, this document contains goals and outcomes that will restore and protect the nation’s largest and most productive estuary. But what will the Agreement mean for the residents of this massive watershed? Read our list to find out.
10. Improved access to the water. From fishing piers to boat launches, people in the watershed want more access to rivers, streams and the Bay. And while partners have opened 69 new access sites over the last three years, access remains limited, with consequences for tourism economies and environmental conservation. Bay Program partners have set a goal to open 300 new public access sites across the watershed by 2025. Learn more.
9. New opportunities to fish in headwater streams. Our increasing need for land and resources has fragmented our rivers and streams, harming the health of those fish that must migrate through unobstructed waters to reach their spawning grounds each spring. Bay Program partners plan to improve stream health and restore fish passage to the Bay’s headwaters, opening up habitat to migratory fish like alewife, American shad and brook trout. More habitat can mean more fish, and more fish can mean more fishing opportunities. Learn more.
Image courtesy theloushe/Flickr
8. Cleaner waters. Nutrient and sediment pollution are behind the Bay’s biggest health problems. Nutrients fuel the growth of harmful algae blooms, which create low-oxygen dead zones that suffocate marine life. Suspended sediment blocks sunlight from reaching underwater plants. Bay Program partners plan to work under the Bay’s existing “pollution diet” to reduce nutrient and sediment pollution, improve water quality, and support the living resources of the Bay, its rivers and its streams. Learn more.
7. Safer waters. Almost three-quarters of the Bay’s tidal waters are considered impaired by chemical contaminants. These substances can harm the health of humans and wildlife, and have been linked to tumor growth in fish, eggshell thinning in birds and intersex conditions in amphibians. Bay Program partners are committed to reducing toxic contaminants in our waters, with a focus on mercury, PCBs and contaminants of emerging and widespread concern. Learn more.
6. Healthy waters that remain that way. Healthy watersheds provide us with clean water, critical habitat and economic benefits. While there are a number of healthy watersheds in the region, development poses a constant threat. Bay Program partners want 100 percent of state-identified healthy waters and watersheds to remain that way. Learn more.
5. A larger community of citizen stewards. The success of our restoration work will depend on local action, and local action will depend on local stewards. Bay Program partners hope to build a larger, broader and more diverse community of citizen stewards who will carry out the conservation and restoration activities that will benefit their local communities and the Bay. Learn more.
Image courtesy peterwalshprojects/Flickr
4. Sustainable seafood. Habitat loss, invasive species, poor water quality and harvest pressure threaten the sustainability of the Bay’s recreational and commercial fisheries. But Bay Program partners have committed to using sound science and responsible management to increase fish and shellfish habitat and populations, leading to more striped bass, blue crabs and oysters in the Bay and on the market. Learn more.
3. Smarter growth. With the largest land-to-water ratio of any estuary in the world, it is clear that what happens on land has a direct impact on water quality in the Bay. But stormwater runoff continues to push polluted rainwater over streets and sidewalks and into storm drains, rivers and streams. Bay Program partners plan to help local governments control polluted runoff, conserve valuable wetlands, farms and forests, and reduce the rate of land that is lost to paved roads and parking lots. Learn more.
Image courtesy Indiana.dunes/Flickr
2. More knowledge and skills to help save our watershed. It is often said that people value what they know and protect what they value. This means that a boost in environmental education now could create a vital foundation for environmental stewards of the future. Bay Program partners will work to enable area students to graduate with the knowledge, skills and meaningful experience needed to protect and restore their local watershed. Learn more.
1. Communities that are resilient to climate change. The impacts of climate change—rising seas, warming waters, extreme weather, ocean acidification—are happening now. To withstand these impacts, we must improve our natural and built infrastructure. Bay Program partners have set a goal to increase the climate resiliency of the watershed’s resources, habitats and communities using monitoring, assessment and adaptation. Learn more.
Note: The opinions expressed above are those of the author and do not necessarily reflect U.S. EPA policy endorsement or action.
According to evaluations released this week by the U.S. Environmental Protection Agency (EPA), Chesapeake Bay Program partners are collectively on track to meet the phosphorous and sediment reduction commitments outlined in the Bay’s “pollution diet,” or Total Maximum Daily Load (TMDL). Further reductions in nitrogen, however, will be needed if partners are to meet all of their upcoming pollution-reducing goals.
Every two years, federal agencies and the watershed jurisdictions—which include Delaware, the District of Columbia, Maryland, New York, Pennsylvania, Virginia and West Virginia—report on the progress made toward the pollution-reducing “milestones” outlined in their Watershed Implementation Plans (WIPs). These WIPs describe how each jurisdiction will reduce the nitrogen, phosphorous and sediment pollution entering rivers and streams, and are included as commitments in the partnership’s recently signed Chesapeake Bay Watershed Agreement. Jurisdictions have set a goal to have all essential pollution-reducing practices in place by 2025 in an effort to meet water quality standards in the watershed.
Nutrient and sediment pollution are behind some of the Bay’s biggest health problems. Excess nitrogen and phosphorous fuel the growth of harmful algae blooms, which result in low-oxygen dead zones that suffocate marine life. Suspended sediment blocks sunlight from reaching underwater plants and suffocates shellfish. But “best management practices” (or BMPs) like upgraded wastewater treatment technologies, improved manure management and enhanced stormwater management can help towns, cities and states lower the amount of pollution flowing into local waters.
The EPA will continue to oversee the watershed jurisdictions’ pollution-reducing efforts, and will offer further attention to some pollution sectors—including wastewater in Delaware and New York; agricultural runoff in Delaware, Pennsylvania and West Virginia; and urban and suburban runoff in Pennsylvania, Virginia and West Virginia—to ensure partners remain on track to meet their 2017 targets.
Scientists expect the Chesapeake Bay to see an above-average dead zone this summer, due to the excess nitrogen that flowed into the Bay from the Potomac and Susquehanna rivers this spring.
Dead zones, or areas of little to no dissolved oxygen, form when nutrient-fueled algae blooms die and decompose. The latest dead zone forecast predicts an early-summer oxygen-free zone of 0.51 cubic miles, a mid-summer low-oxygen zone of 1.97 cubic miles and a late-summer oxygen-free zone of 0.32 cubic miles. This forecast was funded by the National Oceanic and Atmospheric Administration (NOAA) and is based on models developed at the University of Maryland Center for Environmental Science (UMCES) and the University of Michigan.
Dead zone size depends on nutrient pollution and weather patterns. According to the U.S. Geological Survey (USGS), 44,000 metric tons of nitrogen entered the Bay in the spring of 2014. This is 20 percent higher than last spring’s nitrogen loadings, and will influence algae growth and dead zone formation this summer.
Researchers with the Maryland Department of Natural Resources (DNR) and the Virginia Department of Environmental Quality (DEQ) will measure oxygen levels in the Bay over the next few months. While a final dead zone measurement is not expected until October, DNR biologists measured a larger-than-average low-oxygen zone on their June monitoring cruise, confirming the dead zone forecast.