Citing an “ongoing commercial fishery disaster” caused by blue catfish and other nonnative species, Maryland Governor Wes Moore is asking the federal government for fishery disaster assistance.
In a letter to U.S. Commerce Secretary Gina Raimondo, Moore cited growing concern that the population “explosion” of blue catfish, flathead catfish and snakeheads is threatening the Chesapeake Bay ecosystem and commercial fish populations.
All three of the species are predators that can grow to large sizes. Blue catfish are a particular concern because they have spread through many of Maryland’s tidal Bay tributaries in recent years as their numbers and range have grown especially fast.
In some parts of Virginia’s James River, where blue catfish were introduced in the 1970s, they account for 75 percent of fish biomass and can outcompete native species for food and habitat.
In his March 15 letter, Moore said scientists have been seeing “disturbing trends” toward decreased abundance for seven commercial species, including blue crabs and striped bass, since 2012 when blue catfish were beginning to move into the state.
The governor acknowledged that scientists have not made “direct links” between decreased commercial species abundance and the presence of the invasive fish. But, he wrote, “We believe that it is critical to act now to mitigate the effects of the invasive species and to provide assistance to the commercial fishing industry.”
The letter kicks off a formal review process by the U.S. Commerce Department. If the department were to declare a fisheries disaster, it could spur an influx of federal money to support a range of activities. That could include programs that help watermen transition from fishing for traditional native species to the nonnative, invasive ones; incentivizing seafood processors to purchase equipment to handle those species; and marketing efforts to promote sales of those fish.
“I believe that disaster assistance could put Maryland into a position where commercial fishing communities are both supported in the present and positioned for a future of invasive species harvest,” Moore wrote.
The request is not unprecedented in the Bay region. The Commerce Department declared a fishing disaster in 2009 after a sharp decline in the blue crab population. That action resulted in millions of dollars going to Maryland and Virginia for programs that supported watermen and the blue crab fishery.
Allison Colden, the Chesapeake Bay Foundation’s senior fisheries scientist, praised Moore’s request, calling it “a critical first step in addressing the significant problem of invasive catfish and snakeheads in Chesapeake Bay.”
Blue catfish, the largest catfish species in North America, are native to the Mississippi River and Texas Gulf Coast. They can live more than two decades and reach more than 100 pounds, making them a popular sportfish not only in their native range but for anglers and fishery managers looking to import new species.
They were introduced into Virginia’s tidal tributaries in the 1970s to help build a recreational fishery, but their population growth and rapid expansion into most Bay tributaries over the last two decades have raised concern among many biologists about their impact on other species and river ecosystems.
Blue catfish can be significant predators, especially when they reach larger sizes. Some popular Bay species are among their prey, including the blue crab. Scientists have also expressed concern about their potential impact on striped bass and the endangered Atlantic sturgeon.
A diet study of blue catfish by Virginia Tech scientists in the James, Rappahannock and York rivers several years ago – which examined 16,110 blue catfish stomachs – found the fish were omnivores, eating whatever is abundant in the river. All sorts of things turned up in their stomachs, even muskrats, snakes and birds. Overwhelmingly, they eat vegetation and invertebrates, but as they get larger, their diet turns toward other fish.
Recent work by Salisbury University scientists in Maryland have found that blueback herring, alewife and white perch, all species of concern to fishery managers, are common in the stomachs of blue catfish on the Nanticoke River.
A recent study by researchers from the Virginia Institute of Marine Science estimated that blue catfish eat about 2.3 million juvenile blue crabs a year in the lower James River.
Karl Blankenship is editor-at-large of the Chesapeake Bay Journal. This article first appeared in the Chesapeake Bay Journal on March 23, 2023.