81 Northern Snakehead AKA 'Frankenfish' Found In Conowingo Dam

An invasive animal nicknamed "Frankenfish" is rapidly increasing in Maryland waters. The northern snakehead has increased exponentially at the Conowingo Dam, which could be a harbinger of its expansion.

At the Conowingo Dam fish lifts, 81 northern snakeheads were caught this year, officials reported Thursday, June 13. In the past two years, authorities said only one northern snakehead was found there.

The northern snakehead has sharp teeth and looks like a snake with fins that may grow to be up to 3 feet long. It can lay tens of thousands of eggs multiple times each year and survive for days out of water.

It is considered invasive because it has no known predators and voraciously preys upon other fish, according to the Maryland Department of Natural Resources.

The northern snakehead is an "ambush predator that lies on the bottom, waiting for prey," according to a task force designed to study and manage the fish. Wherever it goes, the northern snakehead tends to displace other types of fish, experts say.

In the state of Maryland, those who catch northern snakeheads are encouraged to kill them. To reduce the population of snakeheads, anglers can catch any number of snakeheads year-round and are asked to report these catches to fishingreports.dnr@maryland.gov or 410-260-8300 so that state officials can track the population. In Virginia, Maryland and D.C., there are reward tags on snakeheads to encourage those who catch them in the Potomac River to call and report the information to researchers.

The fish were first found in Maryland in Crofton in 2002, where a family released them into a pond, according to National Geographic, which reported officials poisoned them, but it was too late.

In 2004 the invasive fish was found in the Potomac River and has spread to other tributaries of the Chesapeake Bay, officials say.

After the lone snakehead was observed passing upstream in 2017 in the Susquehanna near the Conowingo Dam, the dam's owner — Exelon — partnered with the Susquehanna River Anadromous Fish Restoration Cooperative to reduce the spread of the fish. It joined fishery representatives from New York, Maryland and Pennsylvania as well as the U.S. Fish & Wildlife Service, National Marine Fisheries Service and the Susquehanna River Basin Commission that are working to manage the snakehead population.

Concerns have mounted with the discovery of 81 snakeheads in the fish lifts at the Conowingo Dam, which are designed to provide safe passage for fish across the dam. While they were killed after they were discovered in the fish lift, Maryland Department of Natural Resources officials said that the increase in snakeheads could mean the invasive species is rapidly expanding to the north in the Susquehanna River.