Based on the most recent data from the James, Potomac, Susquehanna and York rivers, the estimate of Chesapeake Bay-wide American shad abundance increased slightly in 2010 to 28 percent of the goal.
The Potomac River has seen the most consistent increase of returning shad, reaching 97 percent of that river’s target. The York River’s shad abundance is at 20 percent of the goal, while the James and Susquehanna River remain at less than 1 percent.
Date created: Mar 29 2011 / Download
American shad were once the most abundant and economically important species in the Chesapeake Bay. Shad are anadromous fish and spend most of their lives in the ocean, returning to freshwater rivers to spawn after they reach maturity. Data for the York and Potomac Rivers were provided by the Virginia Institute of Marine Science via an ongoing Catch per Unit Effort (CPUE) study involving American Shad gill-netting. Data for the Susquehanna and James Rivers represent published fishway passage values for Conowingo and Boshers Dams, respectively.
What are American shad and why are they so important in the Chesapeake Bay? Learn how scientists are working to protect and restore American shad in our waterways.
Produced by Steve Droter
Stock Footage: Photography by Michelson, Inc. and Jim Thompson, MD DNR
Photos: Library of Congress, LC-DIG-ggbain-18896, LC-DIG-hec-06375
Music: “A Moment of Jazz” by Ancelin
Historically, local economies flourished from the annual shad run in the spring, when the fishes’ upriver migration begins. But shad populations were decimated in the 1970s by overfishing, pollution, and dams and other blockages that prevent the fish from reaching their upstream spawning grounds.
Spawning shad stocks are tracked in four major river systems: the Susquehanna, Potomac, York and James. Two of these rivers have fish passage systems in place so shad can bypass dams and other blockages.
Each river system has its own numeric target:
Long-term trend (2000-2010)
The trend varies among rivers:
Short-term trend (10-year trend)
Same as the long-term trend
Change from previous year (2009-2010)
American Shad Restoration Goal
The restoration goal for American shad is an estimate of the spawning shad stock that can be supported with existing river blockages. The demographics and population dynamics of such a restored shad population are unknown and the potential response to harvest has not been explored. Therefore, attainment of the Chesapeake Bay restoration goals is not connected to fisheries management decisions regarding this species.
American shad are a coastal species. Therefore, the Atlantic States Marine Fisheries Commission (ASMFC) makes management decisions, such as the harvest moratorium and allowable bycatch.
Low shad abundance in the Bay and along the Atlantic coast is thought to be the partial result of bycatch issues in offshore fisheries (located in the Exclusive Economic Zone, or EEZ).
Susquehanna and James River Shad
The Susquehanna and James river counts are determined by fish passage data at York Haven and Boshers Dams, respectively.
The Susquehanna River restoration goal of two million American shad above the York Haven Dam was developed for the 1981 FERC hearings during hydro-project relicensing.
The James River restoration goal of 500,000 American shad above Boshers Dam is based upon the number of shad that can be supported by the 137 miles (11,930 acres) of habitat that became available following construction of the Boshers Dam fishway.
York and Potomac River Shad
Values for the York and Potomac rivers are determined using gill-net data from the Virginia Institute of Marine Science and pound net bycatch and discard data from the Potomac River Fisheries Commission. To determine goal achievement, the 1950s commercial Catch per Unit Effort (CPUE) is compared to the current commercial (Potomac River pound net) or fishery-independent York River monitoring CPUE
National Oceanic and Atmospheric Administration (NOAA)