The 'Alarming' Invasive Fish Threatening PA Waters: What To Know

PENNSYLVANIA — Conservationists are sounding the alarm on the northern snakehead, an invasive fish that can travel across landfish that can travel across land and eat everything from other fish to rodents and birds, after it was caught in a Chester County waterway earlier this month.

The torpedo-shaped freshwater predator sits at the top of the food chain in several states and watersheds where it has established itself, including Pennsylvania. It outcompetes native predators like largemouth bass and stocked fish like trout, and will even eat them if they're not big enough. It also throws established food webs and ecosystems out of balance and into chaos, and could cause immeasurable harm if not stopped, biologists warn.

The fish was recently caught near Black Rock Sanctuary in the Schuylkill River in Chester County. While Pennsylvania environmental officials already knew the fish had a presence in the watershed, the catch served as a reminder to anglers to watch out for the lethal invader.

Anglers "must immediately kill the fish onsite" if they catch it, authorities said.

Origins

Northern snakeheads first appeared in the United States in 1997, and in Pennsylvania in 2002.

They're natives of Siberia, and they can be found in their natural habitat throughout parts of Russia, China, North Korea, and South Korea. A different family of snakeheads thrives in parts of west-central Africa, including Benin and Nigeria, but that is not the northern snakehead that has infested American waters.

It's believed the northern snakehead may have been originally imported to supply the live food fish trade, and released into waterways to broaden the potential market.

"Unauthorized intentional release from this trade, as was the case in the founding individuals of the Crofton pond population in Maryland, continues to be the major mechanism for introduction," the U.S. Fish and Wildlife Service said.

Unwanted fish may have also been dumped from aquariums.

Spread in Pennsylvania and elsewhere

However they originally got here, they've quickly spread to numerous states. It's considered "established" in Virginia, Maryland, Pennsylvania, New York, and Arkansas. It's been captured in California, Illinois, North Carolina, Massachusetts, and elsewhere, but these are generally considered to be isolated incidents.

"They have been found in canals, ponds, lakes, and river systems in more than a dozen states," Jamie K. Reaser, the executive director of the National Invasive Species Council, said in a Department of Interior publication. "The rate of new introductions and their spread within watersheds is alarming.”

The first northern snakehead arrived in the Keystone State in 2004, when angler pulled one from Meadow Lake in Philadelphia's FDR Park in 2004.

A "maze" of interconnected tributaries and tidal sloughs run to and from Meadow Lake, and environmental authorities in the state believe snakeheads to be present both elsewhere in the lower Schuylkill River and the Delaware River, in addition to the lower Susquehanna River near the Conowingo Reservoir.

A few years later, in 2008, a snakehead was caught near the water department in center city Philadelphia.

Investigations and various monitoring efforts have continued in the years since.

"Although young fish were found, the status of the Philadelphia population is uncertain," the U.S. Fish and Wildlife Service shared in a 2017 report. "Officials believe fish may have gotten into the lower Schuylkill River and Delaware River in Pennsylvania and see no practical means to eradicate them.”

Over the land and through the water

A big part of the reason for that "alarming" spread is the unique nature of the fish itself. Northern snakeheads can breathe out of water and survive on land for long periods of time. This allows them to cross land barriers between watersheds and discover new habitats.

"This means they can travel between bodies of water, rapidly expanding their range," a spokesperson for Chester County Parks and Preservation said. "Voracious eaters, they aggressively compete with native fish species for food and habitat."

They also can thrive in low-oxygenated environments, such as tiny, muddy ponds, making them resistant to environmental changes and well suited to various climates and environments across Pennsylvania.

While snakeheads of all changes are able to breathe out of water, they only move across land, in the fashion of a snake, when they are juveniles, biologists say.

Size, shape, diet, details

Snakeheads are long, torpedo-shaped fish that grow to very large sizes: up to 33 inches long, and around 20 pounds, according to the Pennsylvania Game Commission. Their diet is indiscriminate, and they feed on a variety of other freshwater fish, amphibians, some crustaceans, and small mammals they encounter in the water or during their forays on land.

They've even been known to devour birds.

And due to their overall strength and the size of their teeth, they can eat prey up to about a third of their own substantial body size.

The snakehead bears a strong similarity to two stalwart natives of Pennsylvania waters: the bowfin and the burbot.

All three are long, angular, typically brown or auburn-colored, "torpedo-shaped" fish. Bowfin can be distinguished by the lack of scales on their head, while snakeheads have a mosaic of interlocked scales that resembles the skin of a snake.

Burbots, meanwhile, have a barbel on their chin and two dorsal fins, characteristics shared by neither the bowfin or the snakehead.

"Eat it to beat it"

Given this tremendous adaptability and general strength, native fish species and Pennsylvania's aquatic environments would seem to have little chance. But humans can be a part of the solution.

Snakeheads are supposedly quite tasty, with several cooks and experts comparing their flaky meat to flounder and catfish. Because of the nature and texture of the snakehead, they work well with marinades and hold on to new flavors.

And restaurants have taken notice.

"In this case, there is an opportunity to eat it to help beat it," the Department of Interior says.

Several eateries around the region impacted by the snakehead are developing special dishes and menus to help promote its consumption and protect local watersheds.

In Washington D.C., Thip Khao, has a special invasive species menu which often includes snakeheads caught in the nearby Potomac River. True Chesapeake Oyster Co. in Hampden, Maryland also features snakeheads reeled in from the Chesapeake Bay.

It's not yet clear if any Pennsylvania restaurants have taken the bait.

What to do if you catch a northern snakehead

Pennsylvania law prohibits both the possession and sale of live snakeheads, and fishermen who catch snakeheads are urged contact the game commission to report the location and date.

Importantly, the snakehead should be immediately killed.

To report a northern snakehead in Pennsylvania, contact the Pennsylvania Game Commission at 814-359-5163 or complete this form.