What is DNR doing to restore American Shad populations in the Chesapeake Bay?
The American shad is the best-known migratory species in the Chesapeake Bay. But their population has declined since the 1970s due to over-fishing, poor water quality, and stream blockages. To help restore American shad populations, harvesting was prohibited in 1980 for both the recreational and commercial fisherman, a restoration hatchery program was developed, and access to spawning areas was improved.
The Maryland Department of Natural Resources Fisheries Service initiated a program in 1987 to reintroduce American shad to select tributaries through restorative hatchery stocking. Current target tributaries include the Patuxent River, Choptank River and Marshyhope Creek.
Adult American shad enter the Bay during the late winter to lay their eggs in late spring, then leave to return to the Atlantic Ocean. During their spawning run, females are captured and their eggs are stripped, fertilized, and sent to DNR’S Joseph Manning Hatchery, where they are raised under controlled conditions. All stocked fish are marked to distinguish them from naturally spawned fish and then released. Restoration progress is monitored through juvenile and adult sampling studies.
Another objective is to restore access to spawning areas. Historical spawning areas have been blocked by the construction of dams and road culverts. DNR is working with the U.S. Fish and Wildlife Service to remove dams, when feasible. In the meantime, fish ladders - structures on or around artificial barriers to facilitate natural migration - have been constructed to re-open historic spawning habitat. The largest upstream passage structure in Maryland was on the Conowingo Dam on the Susquehanna River.
Finally, several research projects are focusing on improvement in Chesapeake water quality, which is important for all species.
- Bob Sadzinski
- Bob Sadzinski