Aquatic Invasive Animals

 aquatic invasive animals clams

Although aquatic invasive animals are often harder to find than large invasive plant populations, invasive animals can have devastating effects on freshwater ecosystems. Most invasive animals are small and larvae or adults can be transported in bilge water, bait buckets or attached to boats. Others are used as live bait, and extras are discarded into the water. Some were even intentionally stocked. Regardless of the means of introduction, the spread of invasive animals constitutes a serious threat facing our rivers and lakes.



  • cause local extinctions of native species through competition or predation
  • degrade or destroy habitat that supports native fish and wildlife
  • significantly alter aquatic food webs
  • degrade water quality


  • reduce numbers of sport fish, either by destroying suitable habitat, competing for food or by eating them
  • shellfish foul boats and motors


  • damage to infrastructure
  • substantial costs to manage once introduced

Which aquatic invasive animals are in RI?

Species Not Yet Present in Rhode Island

Common Name/
Fact Sheet
Species Name Nearby Infestations
zebra mussel Dreissena polymorpha MA, CT, VT, NY
Click for Map
quagga mussel Dreissena bugensis NY
rusty crayfish Oronectes rusticus MA, CT, VT, NH, ME, NY
Chinese mitten crab (freshwater!) Eriocheir sinensis NY (Long Island Sound/lower Hudson River)
Spiny water flea Bythotrephes cederstroemi NY

Report new identifications of invasive animals to (401) 537- 4217

Stop the Spread of Invasive clams

Stop the Spread!

  • Inspect and clean. Examine your boat and trailer before and after any use. Carefully remove any mud, plant or animal material before transporting your boat, recreational equipment, fishing gear or equipment.
  • Allow time to dry. Clean and dry anything that came in contact with the water (boat, trailers, recreational equipment, clothing, dogs, etc.)
  • Isolate and drain. Empty water from boat wells and motors far away from lakes and rivers.
  • Discard into trash. Dispose any unused bait into proper garbage receptacles; do not empty bait buckets into the water.
  • Prevent releases. Avoid disposing plants, fish or animals from aquariums or water gardens into local water bodies.