Franklin Countys First News

Rangeley Lakes Heritage Trust seeks to stop invasive crayfish

Public enemy number 1!

Public enemy number one!

RANGELEY - This summer, a hidden threat may scuttle beneath the surface of local lakes or ponds. Orconectes rusticus, the rusty crayfish, is an invasive aquatic species that has hitchhiked from its native waters to Maine via the bait buckets of careless anglers. Though it may seem like just another bottom feeder, don’t be fooled: this underwater marauder is one bad crawdad.

The rusty crayfish is known to be aggressive, not only preying on native species of crayfish, but also forcing local species out of the best burrow areas and leaving them more vulnerable to predation. Because they will eat most anything to be found in their environment, including small invertebrate species, aquatic plants, and fish, their presence in great numbers can greatly reduce the diversity and abundance of life normally found in waterbodies. This can cause a ripple effect, negatively impacting the fish and bird populations that share the water environment; what’s worse, once the rusty crayfish has established itself in a lake or pond, no environmentally sound way has yet been found to reduce their numbers.

The Rangeley Lakes Heritage Trust is working to track and slow the spread of the rusty crayfish across our state. The model for this undertaking is a program developed by Dr. Karen Wilson at the University of Southern Maine, and RLHT is working in partnership with the Maine Volunteer Lake Monitoring Program to assess results. Over the summer months and with the assistance of volunteers, the organization is setting crayfish traps in the shallows of multiple waterbodies around Rangeley and Oquossoc and sending a male specimen of each species found to Wilson for identification. RLHT hopes to determine how far the rusty crayfish has spread in the region and create a better overall understanding of what species make up the crayfish population.

So what can be done to help protect the beautiful waters of Maine from the prying claws of the rusty crayfish? Most importantly, people can help slow its spread (and the spread of other invasive species) by taking care not to bring animals, plants, or water from one body of water to another. By cleaning any stray vegetation from propellers, empty live wells, remembering not to bring in non-native bait when fishing, or even just encouraging others to do the same, this type of prevention goes a long way towards ensuring local lakes and ponds remain the envy of New England.

The Rangeley Lakes Heritage Trust would like to thank both Wilson and the Maine Volunteer Lake Monitoring Program for their information and assistance. The organization would also like to sincerely thank volunteers Ellie and Willis White and Barbara Zamierowski- without their help, projects like this would not be possible.

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5 Responses »

  1. Is the Rusty good eating ?

  2. they all eat good.. suck head and eat tail... little meat in the claws but when you have dozens it doesn't matter.

  3. Suck head? Doesn't sound too good!

  4. Other than eating, how would one get rid of these little pests? Also how would one tell the difference between the invasive and native crayfish? I suspect relatives hand dug spring fed pond may have them.

  5. Hi Curious,

    One of the easiest ways to differentiate native and invasive crayfish is by their claws. The Rusty Crayfish will have a oval gap between their claws, while native species will not. Their claws are often smoother, without the "knots" found on our native species claws and tipped with black markings. Another distinguishing mark is a pair of dark, rust-colored spots that appear and the base of their carapace on each side.

    Unfortunately, there is no known way to eradicate a population once it has been established.