Joseph (Brody) Phillips, left, Jack Buchanan and Anna DeMotte of the Virginia Institute of Marine Science seine for juvenile striped bass in the James River in July 2023. Photo courtesy the Chesapeake Bay Foundation.
By Tim Wheeler
Chesapeake Bay Journal
Striped bass continue to suffer from poor reproduction in the Chesapeake Bay, the latest surveys show, increasing pressure on fishery managers to maintain or even tighten catch restrictions on the popular migratory finfish.
An annual seine survey of Maryland’s portion of the Bay collected just 2 juvenile striped bass per haul of the net, the sixth straight year of dismal spawning success, the Department of Natural Resources reported. Though better than the near-record low tally for 2023, it is still well below the long-term average of 11 young fish per haul.
A similar survey of Virginia waters found significantly below-average numbers of recently spawned striped bass there for the second year in a row. The number collected per seine this year was 3.34, the Virginia Institute of Marine Science reported, less than half the long-term average of 7.77 fish per haul for that state’s portion of the Bay.
Chris Moore, the Chesapeake Bay Foundation’s Virginia executive director, said the survey results “continue a disturbing trend for our most iconic Bay finfish and makes it clear that rebuilding the striped bass population is not guaranteed.” He called for further steps to improve spawning success, including seasonal closures of fishing and improving habitat.
Striped bass are found in near-shore waters from Canada to Florida, but the Chesapeake is the primary spawning and nursery ground for 70% to 90% of the entire Atlantic coast stock. Also known in the Bay region as rockfish, they are highly sought after by sport and commercial fishers.
Their spawning success typically varies from year to year, but the overall coastal population has been maintained by bumper crops of juveniles produced every few years. This string of six years of weak reproduction in Maryland is the longest since overfishing in the 1970s and ’80s led to a near-collapse of the population, prompting catch restrictions coastwide, and even bans in Maryland and Virginia.
The population rebounded from that swoon but in 2019 scientists determined they were being overfished again, warning that even catch-and-release fishing practiced by sports anglers was a major factor because many fish hooked in hot weather died after being released.
The Atlantic States Marine Fisheries Commission, which oversees near-shore fishing of migratory fish along the East Coast, has ordered a series of restrictions on recreational and commercial catch since then. An updated stock assessment found striped bass remain overfished and it is not certain that the catch limits imposed so far will be enough to meet the goal of rebuilding the population by 2029.
Fishery managers and scientists in both states survey traditional striped bass spawning areas every year, sweeping shallow waters multiple times through the summer with a 100-foot seine net. In Maryland, the survey regularly samples the Choptank, Nanticoke and Potomac rivers and the upper Chesapeake Bay. This past summer, DNR also surveyed the Patapsco, Magothy, Rhode, West, Miles and Tred Avon rivers, where they likewise found fewer juvenile striped bass.
In Virginia, annual checks are made in the Rappahannock, York and James River systems. Fish captured in the net are counted, measured and returned alive to the river. The young striped bass collected range from 1.5 to 4 inches in size. Fish spawned this spring would normally reach catchable size in three to four years.
Researchers have suggested the poor survey results may stem at least in part from warmer, drier winters triggering earlier spawning, before there are enough microscopic zooplankton in the water on which striped bass larvae depend for food.
“These results underscore the complexity of managing a coastal migratory species whose life cycle is influenced by environmental conditions during a brief spawning period,” said Lynn Fegley, Maryland DNR’s fisheries and boating director. “We will continue to explore ways to conserve and enhance the spawning population during this time when we are adding fewer young fish to the population.”
Though proof is lacking, others suspect the dramatic increase of blue catfish throughout the Chesapeake may also be a factor, as the now-abundant invasive species eats other fish and crabs.
A recently published study by VIMS researchers finds that conditions in the shallow near-shore areas where juvenile striped bass spend their summers also may affect their abundance.
Using computer modeling, the VIMS scientists compared juvenile fish survey results from 1996 through 2017 with water conditions recorded in those areas each year, including salinity, temperature, currents and dissolved oxygen levels. Over that time period, they found decreases in suitable habitat for young striped bass in about half of the 10 major spawning areas in Maryland and Virginia.
Conversely, they also found places such as the Upper Bay and a few rivers where the extent of suitable habitat increased in early summer. But overall, said study co-author Troy Tuckey, a VIMS senior research scientist, the analysis showed that “when there was more suitable habitat, more area available, we had stronger year classes of juvenile striped bass.”
While this study wasn’t designed to identify the causes of habitat loss, Tuckey suggested that changes in land use, tree cover and runoff from development could be factors.