Our Cold, Snowy Winter could Benefit Rockfish Population

Long, wet, snowy and cold winters, as 2025 has brought us, are just the thing to spark at least “cautious optimism” in Maryland’s striped bass program manager.

Beth Versak of Maryland’s Department of Natural Resources said this week that really cold and snowy winters can result in above-average spawn success. That could lead to a strong year-class of juvenile striped bass–known locally as rockfish–in 2025 which in turn could lead to a nice infusion into the overall striped bass population along the Atlantic coast.

“The past six winters have been relatively warm and not too wet,” said Versak.  “This year is  different.”

Warm winters, she said, can create a mismatch between production of zooplankton in the Chesapeake which feed tiny rockfish larvae. The zooplankton life cycle continues in warmer winters meaning less food for the rockfish larvae when they really need it.

Cold winters however can cause a pause in the lifecycle of the microscopic plankton.  When warmer water returns in the spring, the plankton life cycle resumes which can create an abundance of food just when the spawned larvae need it.

It’s all about timing.

“Just after the spring spawn,” she said, “eggs hatch and the larvae feed initially on what remains in the yolk sack. After the yolk is gone, they begin feeding on the plankton.

“‘Cautiously optimistic’ may be too strong,” said Versak, “because there are so many other variables. We won’t really know the effect of this year’s cold winter until we begin surveying the juvenile index for the 2025 year class in July.  By that time the young fish should have grown to about two inches in length and we can begin gathering them in fishing gear to determine just how many have survived from this year’s spawn. That’s called the young-of-the -year survey and it continues through August and September followed by our annual juvenile index report in October.

“By then the young fish should have grown to about four inches. People anxiously await that statistic.”

And why is that Chesapeake Bay statistic so anxiously awaited?

“In any given year,” said Versak, “seventy to ninety percent of the spawning stock of the entire Atlantic coast striped bass population is produced in Chesapeake Bay. The current spawning stock biomass level–all of the mature, spawning fish in the entire adult population–is capable of producing a good year class when environmental conditions are correct. Of course we’re relying on mother nature here but currently the population is holding. They’re tough fish.”

So there’s the silver lining to this year’s tough winter, spiced with just a touch of gray.

Striped bass historical perspective

Here’s an excerpt from a current DNR press release about the striped bass population.

“Many Maryland anglers remember the striped bass population collapse of the 1970s and 1980s, leading to a moratorium on striped bass fishing until 1990. Concern about low recruitment over the last several years can lead to comparisons to this dire period in the history of striped bass fishing, but the reality is not that stark.

“The female spawning stock biomass for coastwide populations of Atlantic striped bass was 191 million pounds in 2023, which is below coastal management goals but more than three times higher than the biomass recorded in the mid-1980s and at a similar level to 1993 and 2015, years when very large year-classes were produced.”

The full text of that release cann be found here.

Striped bass life cycle

And for those interested in facts about the overall striped bass life cycle, here’s this from the website of the Atlantic States Marine Fisheries Commission, a federal agency rooted in science and charged with helping to manage fisheries resources:

“Atlantic striped bass (Morone saxatilis) are an estuarine species that can be found from Florida to Canada, although the stocks that the Commission manages range from Maine to North Carolina. A long-lived species (at least up to 30 years of age), striped bass typically spend the majority of their adult life in coastal estuaries or the ocean, migrating north and south seasonally and ascending to rivers to spawn in the spring.

“Mature females (age six and older) produce large quantities of eggs, which are fertilized by mature males (age two and older) as they are released into riverine spawning areas. While developing, the fertilized eggs drift with the downstream currents and eventually hatch into larvae. After their arrival in the nursery areas, located in river deltas and the inland portions of coastal sounds and estuaries, they mature into juveniles. They remain in coastal sounds and estuaries for two to four years and then join the coastal migratory population in the Atlantic Ocean.

“In the ocean, fish tend to move north during the summer and south during the winter. Important wintering grounds for the mixed stocks are located from offshore New Jersey to North Carolina. With warming water temperatures in the spring, the mature adult fish migrate to riverine spawning areas to complete their life cycle. The majority of the coastal migratory stock originates in the Chesapeake Bay spawning areas, with significant contributions from the spawning grounds of the Hudson and Delaware Rivers.”

Dennis Forney has been a publisher, journalist and columnist on the Delmarva Peninsula since 1972.  He writes from his home on Grace Creek in Bozman.