Aquatic Invasive Species

Fishing Regulations New Jersey Freshwater Fishing

Invasive Alert—New Zealand Mud Snail Found in New Jersey Waters!


The invasive New Zealand Mud Snail has been officially documented in the Musconetcong River at several locations downstream of Rt. 78 between Warren and Hunterdon counties. This species is a threat to our freshwaters and may compete with and displace native invertebrates.

Despite its name, New Zealand Mud Snails can tolerate a wide variety of habitats, including reservoirs, estuaries, rivers and lakes. They are most prolific in waterbodies with a constant temperature and flow but are highly adaptable. Measuring just 4–5 mm in length, they are easy to overlook—yet a single female can result in a colony of 40 million snails in one year!

IMPORTANT: All anglers and boaters are urged to help protect New Jersey’s aquatic resources by inspecting equipment transported between waterways, including boats and trailers. Drain, clean and dry all equipment and clothing BEFORE visiting other waters!

Invasive Fish

Fish identification can be easy for species caught frequently, but tricky for species new to New Jersey waters. An untrained eye can mistake species that look similar.

Snakeheads are invasive and should be destroyed. They have been found in the lower Delaware River and some of its tributaries.

Bowfins, once believed to be native, are now considered to be an introduced species. Their impact, if any, on the state’s fisheries resources has yet to be determined.

American eels are a diadromous native species, using both fresh and marine waters during their lifecycle. These eels are found in nearly every waterbody in New Jersey. American brook lamprey are a harmless native species that serves as an indicator of clean substrate. The Asian swamp eel is an invasive species with documented presence in Silver Lake, a 10-acre waterbody located in Gibbsboro.

Although not a native species, channel catfish are stocked by Fish and Wildlife in select locations as a recreational and food species. The flathead catfish is considered an invasive species capable of causing ecological damage by out-competing other recreationally important species for food and habitat. Flatheads have been confirmed in the middle section of the Delaware River.

Water Chestnut

Pat Hamilton/NJDFW

Fan-shaped, strongly toothed leaves. Nut-like fruit with four sharp spines.

Keep on Reporting

The most effective way to succeed in containing aquatic invasive species is to report each encounter. Anglers are reminded that possession or release of flathead catfish, snakehead, Asian swamp eel, brook stickleback, oriental weatherfish, green sunfish and warmouth, bighead carp, silver carp and grass carp (diploid) is prohibited. Anglers must destroy these species if encountered and submit specimen(s) to the Bureau of Freshwater Fisheries at (908) 236-2118 for north Jersey and at (609) 259-6964 for south Jersey. For photo I.D. confirmation, write us at njfwfish@dep.nj.gov.