The invasive northern snakehead fish has negatively impacted other fish and the ecosystem in part of the Chesapeake Bay, according to a recent study by a Maryland Department of Natural Resources biologist and other scientists.
Native to East Asia, the northern snakehead (also known as Chesapeake Channa) was first documented in Maryland in 2002. The species has since expanded its population here, after more fish were illegally introduced and naturally dispersed.
Scientists with the state’s natural resources department compared fish communities in the Blackwater River drainage near Cambridge, Maryland, before and after Chesapeake Channa invaded local waters. Chesapeake Channa were first reported in the Blackwater River in 2012.
The study found that the populations of 19 out of 22 resident species had declined since the introduction of the non-native species, changing the ecosystem’s community structure and biodiversity.
White perch, brown bullhead, and black crappie were the three most abundant fish species before the Chesapeake Channa was introduced to the area. Six years later, the three most abundant fish species were common carp, gizzard shad, and white perch, in that order.
Most species’ abundance declined since the introduction of Chesapeake Channa, but scientists found that black crappie, white perch, bluegill, and pumpkinseed fish – all popular prey for Chesapeake Channa – experienced the greatest losses.
Department of Natural Resources fisheries biologist Dr. Joe Love, and co-authors Joshua J. Newhard and Meghan Walker, published their findings in the Journal of Fish and Wildlife Management online in November 2024.
“We know that this is an opportunistic, predatory species that could impact native fish populations, but before this study, whether their predation has changed the composition of aquatic communities was unknown,” Love said.
Rather than changing water quality conditions, the scientists found that predation or displacement were the likely explanations for the changes to other fish populations and the ecosystem.
The scientists noted that the Chesapeake Channa’s impact on the Blackwater River, the area that they studied, may not be the same for other waterways.
The state has encouraged sportfishing and commercial harvesting of Chesapeake Channa and other invasive fish species.
DNR reports that Chesapeake Channa has a similar mild taste and firm texture as blue catfish.
For more information about fishing for Chesapeake Channa, visit DNR’s website.
What studies were done on water quality? And on the invasive catfish?
This has been a new fact for 27 years…..
They found an incredibly weak correlation following an 11 year gap in survey data. They did not establish causation, period, full stop. That decline could have been caused by any number of factors as easily as it was caused by northern snakehead and probably WAS caused by something else. Yet they put out a press release claiming this study found something it didn’t. DNR has a vested interest in making snakehead out to be a problem because it gets them federal funding to combat invasives. Follow the money and stop the shoddy science.