Invasive Aquatic Species

Delaware, along with other states in the Mid-Atlantic Region, has been invaded by non-native aquatic species that pose a threat to native species, to ecological processes, and to the economy.

A composite graphic showing images of fish considered to be invasive species with the words Most Wanted above them.

An invasive species is a non-native species whose introduction causes or is likely to cause economic or environmental harm or harm to human health. Generally, successful aquatic invasive species are able to tolerate a wide range of environmental conditions. They exhibit rapid growth and maturity. They produce a large number of offspring. and have few natural predators.

Once established, invasive plant and animal species are costly and difficult to control and can be impossible to completely eradicate. Preventing the introduction and spread of these species is key to averting long-term ecosystem damage. The best approach is to have an informed public that can identify invasive species, report occurrences, and help the effort by not introducing or spreading them in the state.

How Do They Get Here?

There are many ways that invasive species are introduced into a new area:

  • Ship Ballast Water and Ship Hull Fouling
  • Intentional and Illegal Stocking
  • Educational/Religious Practices
  • Discarded Live Fishing Bait
  • Climate Change and Weather Related Events
  • “Hitchhiker” on Boats, Trailers, Boots, or Other Recreational Gear and Equipment
  • Attached to Animal Fur, Feathers or in Feces
  • Escape from Aquaculture Facilities and Live Food Markets

Known Invasives in Delaware Waters

What You Can Do

Report Invasive Species
302-735-2966 or 302-739-9914
(Weekdays, 8 a.m. to 4:30 p.m.)
Invasive Fish Tracker

Members of the public are key to preventing the invasion and spread of aquatic invasive species. You can help by reporting very unusual aquatic plant and animal species to the DNREC Division of Fish and Wildlife. Please include the date, a specific location, and a photo to confirm species identification.

You can report invasive aquatic species by telephone, via email, or online using Delaware’s Invasive Fish Tracker.

It is also important to keep an eye out for invasive terrestrial species. They should be reported to the Wildlife Section, at 302-739-9912.

More Information