The 2026 juvenile index was 5.5, compared with a historical average of 10.8, according to the Maryland Department of Natural Resources. The index measures the average number of young fish caught in a single sweep of a seine net. The fish sampled were generally 3 inches long or smaller.

“The important piece of information is that it is still below average, and it is now the eighth year of low abundance,” said Carrie Kennedy, who leads the department’s Tidal and Coastal Monitoring and Assessment Division.

Virginia’s survey showed a stronger result: its index was 9.52, above that state’s historical average of 7.77. Maryland’s survey, conducted since 1954, is one of the country’s longest-running fish surveys.

Kennedy said warmer water and other changing environmental conditions could be affecting striped bass reproduction. The state’s results may point to a lasting shift, she said, and fisheries managers may need to reconsider what counts as a normal level of juvenile fish in a changed Chesapeake Bay.

The low numbers are not confined to striped bass, Kennedy said. White perch and yellow perch, which also migrate between freshwater and the ocean, have shown similarly low recruitment — the addition of young fish to the population — over the past seven or eight years. That pattern suggests broader environmental pressures may be at work.

The Bay is a crucial spawning ground for Atlantic striped bass, commonly called rockfish in Maryland. About 80% of the coastwide population spawns in the Chesapeake, said Allison Colden, Maryland executive director of the Chesapeake Bay Foundation. She called the string of poor survey results bleak and said protecting the species will require action across its range.

Maryland has already tightened some fishing rules. The state canceled its spring trophy fishery in 2024, and recreational anglers may now catch and release striped bass from Jan. 1 through April 30. The fishery is also closed in August, when warmer water can increase the risk that released fish will die.

The latest juvenile count is not expected to change Maryland’s rules next year. The state is awaiting a coastwide striped bass stock assessment, likely next spring, before the Atlantic States Marine Fisheries Commission considers new restrictions. The commission declared the species overfished in 2019 and has a plan to rebuild the stock by 2029.

The assessment will show whether the population is on track to meet that goal or whether further measures are needed. Kennedy said Maryland could adopt stricter rules after the commission acts, but any additional state restrictions would likely not take effect until the 2029 fishing season.

There are reasons for cautious optimism about the adult population, Kennedy said. But young fish generally take seven to eight years to mature and spawn, meaning the repeated weak juvenile classes could soon become more visible in the number of adults.

This summer, biologists sampled 22 locations across four Maryland rivers where striped bass spawn. They made two shore-based seine-net sweeps at each visit. The strongest results came from the upper Chesapeake and the Choptank River. Survey crews caught nearly 72,000 fish representing 62 species; Atlantic menhaden, a key part of the Bay’s food web, were plentiful, Kennedy said.