I enjoy eating fish. I also enjoy catching them. And after learning about the impact that a couple of recent invaders have had on the Chesapeake Bay, I’ve added two new fish species to my catch list.
About a year ago, I sat in a meeting (which I do a lot) and listened to a presentation on yet another threat to the Chesapeake Bay’s aquatic environment. This threat came in the form of the blue and flathead catfish, the finfish equivalent to the invasive zebra mussel that has upset the aquatic ecosystem of the Great Lakes.
Blue catfish are considered “apex predators”; they sit at the top of the food chain. They consume not only other finfish, but shellfish as well. They have no predators. Introduced to Virginia’s James, Rappahannock and York rivers as a sport fish in the 1960s, ‘70s and ‘80s, they have multiplied and extended their reach into other parts the Bay. Apparently, they are here to stay.
Recently, the Maryland Department of Natural Resources (DNR) launched a public awareness campaign to promote a “catch and cook” movement in place of the usual “catch and release” program. The agency is working with restaurants and fish processors to market these catfish. During the campaign’s April kick-off event, we were treated to samples of what these demons of the deep might taste like. I went back for seconds (several times). This is a great source of protein for those who rely on fishing for both sustenance and subsistence. And while catfish are bottom feeders, I’ve been assured that, as long as we eat fish that are smaller than 32 inches, there shouldn’t be any concern about the bioaccumulation of toxins. Good to know.
The Bay has become home to other invasive fish, as well. We all remember the northern snakehead! While this critter isn’t as pervasive as the blue catfish, it is another species that has pushed portions of the Bay ecosystem out of balance. But let me recommend a snakehead ceviche. If you can’t beat ‘em, eat ‘em! Bon apetit!
Note: The opinions expressed above are those of the author and do not necessarily reflect U.S. EPA policy endorsement or action.
The Maryland Department of Natural Resources (DNR) has launched a state-wide campaign to teach citizens about the impact of blue and flathead catfish and encourage anglers to remove the invasive species from local rivers and streams.
Native to the Mississippi, Missouri and Ohio river basins, blue catfish were introduced to the James, Rappahannock and York rivers in the 1970s and ‘80s as a sport fish. Flathead catfish were introduced to the James in the 1960s for the same reason. Over time, the natural movement and purposeful introduction of the fish into new waters have hastened their establishment in Chesapeake Bay tributaries.
This concerns scientists, who fear the fast-growing and long-lived blue catfish, in particular, could impact the region’s ecologic and economic resources. Because of its opportunistic feeding habits, the blue catfish has become an apex predator, disrupting the structure of the Bay ecosystem and eating up critical aquatic species.
Indeed, “gut content analyses” of the fish have found American shad, Atlantic menhaden, freshwater mussels and blue crabs in their stomachs. Peyton Robertson, director of the National Oceanic and Atmospheric Administration’s Chesapeake Bay Office and chair of the Chesapeake Bay Program’s Sustainable Fisheries Goal Implementation Team, compared the blue catfish to a Bengal tiger, noting that the fish eats “just about anything.”
“If left unchecked, [blue catfish] could, as top predators, start to impact other parts of our ecosystem,” Robertson said.
But its eradication isn’t feasible, and experts believe the invasive fish is here to stay. So managers hope to mitigate their spread and minimize their impact on native fish.
With support from the Bay Program, DNR has established more than 150 signs at water access points and kiosks around the state to help anglers identify, catch and keep the species, while Maryland Seafood has escalated its efforts to market the fish to restaurants and boost consumer demand.
“[Humans] are great at overfishing things,” said Maryland Seafood Marketing Director Steve Vilnit. “And [the blue catfish] is a species that we want to overfish.”
Fisheries scientists with the Chesapeake Bay Program will develop a Chesapeake Bay-wide management plan for blue and flathead catfish, two invasive fish species that pose a significant threat to the health of rivers in Virginia, Maryland and Pennsylvania.
(Image courtesy USFWS Headquarters/Flickr)
Invasive species are animals and plants that are not native to their current habitat and harm the ecosystem they invade. Invasive species are able to thrive in new areas because they lack predators, diseases and other natural controls that keep them in check in their native environment.
Although they are valuable recreational species, blue and flathead catfish are harmful to the Bay ecosystem for several reasons. They grow to enormous sizes, have massive appetites, reproduce rapidly and live for many years. As top-level predators in the Bay food web, blue and flathead catfish prey upon important native species such as American shad and blueback herring.
Both catfish species have been present in Virginia rivers since the 1960s. In recent years, anglers have caught these fish in the Potomac and Susquehanna rivers, as well as the upper Chesapeake Bay. The spread may be due to people moving fish from one river to another, even though this is illegal in Maryland and Virginia.
Scientists will consider a variety of actions to control and lessen the harmful effects of these invasive catfish. For more information, read the Bay Program fisheries team’s Invasive Catfish Policy Adoption Statement.
The Bay Program fisheries team includes experts from the Virginia Department of Game and Inland Fisheries, Virginia Marine Resources Commission, Potomac River Fisheries Commission, D.C. Department of the Environment, Maryland Department of Natural Resources, Atlantic States Marine Fisheries Commission and the National Oceanic and Atmospheric Administration.