NOAA Project to Investigate Impacts of Shallow Water Hypoxia in Chesapeake Bay

Researchers examine “night and day ‘swings’” in oxygen depletion on finfish and oyster habitat

September 21, 2010

NOAA has awarded a team of researchers, led by the Smithsonian Institution, $634,047 as part of a planned five-year grant, estimated at nearly $1.6 million, to predict the impact of hypoxia on commercially and ecologically important finfish and oysters living in the shallow waters of the Chesapeake Bay.

Results of this study will help Bay area officials pinpoint key areas for habitat and fisheries restoration, and better protect shallow water habitat that serves a critical nursery function.

Hypoxia is a condition in which dissolved oxygen in the water becomes too low to support most life or compromises the growth, reproduction and immune responses of organisms. Although hypoxia can occur naturally, it is often worsened or caused by excess nutrients from human activities such as agriculture and the burning of fossil fuels.  

The deep waters of the Chesapeake’s main stem, as well as some of its tributaries, experience hypoxia every summer. As oxygen monitoring has increased in shallower, near-shore areas of the estuary, it has also become apparent that many of these habitats experience day-night “swings” in oxygen concentrations that result in low oxygen during night and early morning hours.

The study will examine whether daily hypoxia can result in declines in fish production and biomass. The study will focus on species with significant commercial value for the region, including summer flounder, striped bass, white perch and the eastern oyster, as well as important prey fish such as weakfish and mummichog.

Researchers also plan to study acidification in the Chesapeake Bay, which is linked to hypoxia and may exacerbate its impact on fish and oysters.

“This research will enhance our efforts to accelerate the restoration of Chesapeake Bay and contribute to the re-establishment of fisheries that have suffered steep declines during the past decades. The Bay provides thousands of jobs to the region, and we have a responsibility to improve the health of this treasured resource for generations to come,” Sen. Benjamin L. Cardin (D-MD) said.

“Finding out when and where low oxygen ‘swings’ occur will help state and federal agencies make important management decisions related to the Bay’s coastal and marine ecosystems,” said Peyton Robertson, director of the NOAA Chesapeake Bay Office and chair of the Chesapeake Bay Program's Fisheries Goal Team. “I'm pleased that this research will draw on some of the top-notch scientists from academic institutions and federal and state governments to more clearly define the effects of hypoxia on finfish and oysters, enabling us to better protect and restore their habitats.”

The research team, led by Denise Breitburg, Ph.D., of the Smithsonian Environmental Research Center, includes scientists from the University of Delaware and Louisiana State University who will collaborate closely with state and federal management agencies, including NOAA’s Chesapeake Bay Office, EPA’s Chesapeake Bay Program and Maryland’s Department of Natural Resources.

First-year funding has been awarded to the University of Delaware ($246,844), Louisiana State University ($74,834) and the Smithsonian Institution’s Environmental Research Center in Maryland ($312,369).

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