Two independent analyses are pushing back on a key claim driving current Atlantic menhaden management discussions, that Virginia’s reduction fishery is preventing fish from reaching Maryland waters.
According to a May 4 release from the Menhaden Fisheries Coalition, both a statistical review and an oceanographic study found no evidence supporting the idea that Virginia’s Chesapeake Bay purse seine fishery is “blocking” menhaden migration to the upper bay.
The findings were submitted to the Atlantic States Marine Fisheries Commission (ASMFC) Atlantic Menhaden Management Board through a comment letter from Ocean Harvesters, as regulators consider a proposed addendum focused on the timing of the reduction fishery.
A statistical analysis by Georgetown Economic Services examined Virginia purse seine “net sets” alongside Maryland pound net landings. If interception were occurring, Maryland catch rates would be expected to decline as Virginia fishing activity increased.
Instead, the study found the opposite.
“When Virginia set activity is higher, Maryland’s menhaden catch per trip tends to be higher,” the report concluded, noting a statistically significant positive relationship between the two fisheries. The findings suggest both are responding to the same underlying factor, fish availability in the Bay, rather than competing for the same migrating stock.
A second analysis led by Arnoldo Valle-Levinson, a professor at the University of Florida, focused on environmental conditions in Chesapeake Bay. His work highlights how seasonal factors like hypoxia (low oxygen levels) can compress fish into smaller habitable zones, influencing catch rates without any need for a “blocking” mechanism.
The study also found that while Maryland pound net landings have declined over the past decade, fishing effort has declined as well. Catch per unit has remained largely stable, suggesting that lower harvest totals do not necessarily indicate fewer fish.
Valle-Levison’s analysis further links river discharge, water column stratification, and hypoxia depth to menhaden distribution, describing what the report calls an “estuary cascade” where environmental conditions can concentrate fish and affect catchability.
The ASMFC’s Plan Development Team has already recommended that the addendum’s central premise receive further scientific review by the commission’s Technical Committee, calling it a “more appropriate avenue” for detailed analysis.
According to the coalition, the new findings reinforce that recommendation and point toward environmental drivers, not fishery timing, as the primary influence on menhaden availability in the Chesapeake.
