Spiny waterfleas (Bythotrephes longimanus) are aquatic zooplankton (small animals) from Europe and Asia that have invaded the Great Lakes ecosystem, as well as some inland water bodies. Infestations of spiny waterfleas negatively impact native fish populations, aquatic habitats, and sports fishing. There is no successful method of control.
Description
Adults range from ¼ to ⅝ inch long and they have a single long tail with 1-3 sets of small spines along its length.
Distribution and Habitat
Spiny waterfleas live in fresh water habitats and prefer cold temperatures, but can tolerate both brackish and warm water. They have spread throughout the Great Lakes and have been found in more than ten counties in New York State. Lake Erie, Lake Ontario, Lake George, Saratoga Lake, Lake Champlain and a number of smaller water bodies are infested.
Environmental Impact
Spiny waterfleas eat smaller, native zooplankton that are important food for both small crustaceans and native fish such as perch. In some lakes, they have eliminated native zooplankton from the food chain, causing serious declines in native fish populations. In the Great Lakes, spiny waterfleas have been associated with the decline of alewife.
Spiny waterfleas also interfere with fishing, as their spines catch on fishing line, resulting in clogged fishing rod eyelets and damaged reel systems, preventing fish from being reeled in.
Spread
Spiny waterfleas were introduced to the Great Lakes through the ballast water of cruise ships, tankers and cargo carriers. Spiny waterfleas spread by attaching to fishing lines, downriggers, anchor ropes, and fishing nets and hitch a ride to other waterbodies. They can also be transported in bilge water, bait buckets, live wells, and the bottoms of canoes and kayaks.
How You Can Help
There is no known control method for the spiny waterflea once it is introduced, so preventing the spread of this invasive is critical.
- Clean, drain, and dry your watercraft and equipment thoroughly before visiting other waterbodies.
- Inspect and remove debris and mud from boats, trailers, and equipment.
- Dispose of all debris and bait in trash cans or at disposal stations.
- Drain all water-holding compartments including live wells, bait wells, and bilge areas. If possible, visit a decontamination station and disinfect compartments with hot water (140°F) for at least 30 seconds.
- Dry boats, trailers, and all equipment before use in another water body. A minimum of 5-7 days of drying time in dry, warm conditions is recommended.
- Soak fishing gear and equipment in hot water (140 degrees F) for two minutes.
- Use certified bait that is non-invasive and disease free.
- Learn how to identify spiny waterfleas and report any encounters.
- If you think you have found a spiny waterflea:
- Email the photos, noting where it was caught (coordinates preferred), to [email protected], OR
- Submit a report through iMapInvasives, OR
- Contact your local Partnership for Regional Invasive Species Management (PRISM).