Fish in Tidal Fresh Potomac Estuary and Anacostia

Interstate Commission on the Potomac River Basin

Anacostia River Fish Surveys

A multi-year, multi-agency study of the Anacostia River watershed documented water quality, physical habitat conditions, and fish distributions before and after fish habitat restoration efforts.

The fish surveys tracked the migratory extent of anadromous fish into the Anacostia watershed in spring and documented resident species present in the watershed. Surveys were performed with shore seining and electrofishing techniques. Analytical tools were developed to evaluate the effectiveness of pollution abatement methods to improve fish habitat. Comparisons of residence species diversity and abundance to 1948 and 1972 survey results showed an increase in diversity in 1988 driven by increases in pollution intolerant (sensitive) species and fewer pollution tolerant species.

Results of the resident species survey suggests fish habitat in much of the watershed is improving. Sligo Creek continued to exhibit low species diversity and Lower Beaverdam had primarily pollution tolerant fish species. Herring larvae stocking efforts by ICPRB to boost migratory fish populations in the Anacostia were also done in 2000 and 2001.

Relevant Reports

American Shad

Until recently, levels of American shad were depressed in the Potomac River despite significant water quality improvements made over the last several decades and a river harvest moratorium in effect since 1982. Opening the Little Falls Fishway in 2000 was expected to improve shad abundances but stocking efforts could jump-start the recovery.

A collaborative stocking effort lead by ICPRB between 1995 and 2014 was designed to imprint American Shad to their historic spawning and nursery waters before the fishway opened and then help rebuild the stocks. With this stocking effort, shad abundances rose quickly in the Potomac River.

The higher abundances are evident in young-of-year shad numbers collected in summer seine surveys performed by Maryland Department of Natural Resources and the Gunston Cove Ecosystem Study. The need to monitor and keep track of shad restoration progress still remains. Other pressures on the population are occurring and indicate the continued need for management action to reduce adult mortality (Atlantic State Marine Fisheries Commission, 2021).

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