Striped bass support one of the most important commercial and recreational fisheries on the Atlantic Coast, and the Chesapeake Bay provides these fish with critical spawning and nursery grounds. To monitor the health of the striped bass population, scientists track the biomass of adult female striped bass and the relative abundance of striped bass that are less than one year old.
In 2015, the biomass of adult female striped bass along the Atlantic Coast weighed an estimated 139 million pounds. This is below the target of 159 million pounds but above the overfished threshold of 127 million pounds. Multi-state fishing bans set in the late 1980s and harvest limits set in the 1990s were critical to rebuilding the striped bass stock from its historic mid-1980s lows.
Between 2016 and 2017, the relative abundance of juvenile striped bass in Maryland and Virginia waters—including the Upper Bay and the Choptank, Potomac and Nanticoke rivers in Maryland and the Rappahannock, York and James rivers in Virginia—increased. To calculate the juvenile striped bass abundance index, scientists take seine net samples in noted striped bass spawning areas. The average number of rockfish that are less than one year old caught in each seine haul becomes the abundance index. These young-of-the-year fish will grow to a fishable size in three to four years.
In Maryland waters, the abundance index rose from 1.25 to 13.2, which is well above the long-term average. In Virginia waters, the abundance index rose from 5.44 to 8.98, which is just above the long-term average.
These juvenile striped bass abundance indices serve as early indicators of future adult fish abundance and help managers predict the amount of adult fish that will be available for commercial and recreational fishermen. Maryland Department of Natural Resources Fishing and Boating Services Director David Blazer called Maryland's 2017 abundance index "encouraging" in a media release.