Attention Maryland fishers: If you harvest a northern snakehead from state waters, you might be eligible for a gift card worth up to $200.

State and federal wildlife managers are placing yellow or blue tags on up to 500 northern snakeheads in Maryland waters. It’s part of an effort to gauge population growth for the species, which both the Maryland Department of Natural Resources and U.S. Fish and Wildlife Service have seen spreading through the upper Chesapeake Bay.

“By measuring the amount of northern snakehead harvested, the agencies will learn if population bench marks are being reached and help control the spread of the species,” DNR said in a statement.

“Harvesting snakeheads helps reduce predation pressure on the state’s natural resources, and the fish is also considered a flavorful and nutritious food source.”

Each tagged northern snakehead caught and harvested until 2024 could be eligible for a gift card worth between $10 and $200, depending on its tag, DNR said.

If you’ve harvested a tagged snakehead, report it to USFWS by calling 800-448-8322. You’ll be asked to report its tag number and submit a photo of your harvest in order to qualify for the reward.

Fishers are reminded that federal law forbids the transport of live northern snakeheads in Maryland and surrounding states. Anyone fishing in state waters age 16 or older must have a valid license.