RLHT Continues Invasive Crayfish Investigations

Rangeley, ME – Over the course of the last two seasons RLHT has assisted Dr. Karen Wilson of University of Southern Maine with mapping the spread of the rusty crayfish (Ornectes rusticus) in the Rangeley Lakes Region. This project is part of an ongoing effort to gain a clear picture of crayfish populations across our state and to determine how far the invasive rusty crayfish has spread in Maine.

“The first season the waters were tested, so to speak,” said Amanda Laliberte, Headwaters Lake Protection Program Manager for RLHT. “Staff and volunteers collected crayfish in every body of water in our region to see if rusty crayfish were present. The results were varied and very little was definitive.”

Throughout the 2017 season, RLHT staff collected specimens at specific locations determined by the previous year’s data. Streams and rivers leading into water bodies were the focus. This spring the results were in. Positive identification for rusty crayfish were found on Quimby Pond and another area with an infestation was found on Rangeley Lake.

This season investigations will focus on determining how far invasive crayfish have travelled along the shoreline. “Unlike other organisms in the lake, crayfish must literally crawl to expand their populations,” said Laliberte.

The rusty crayfish is an invasive species most likely introduced to our waters via bait buckets. It can be identified by its large size, a rust-colored spot on each side of its carapace and, most distinctively, an oval-shaped gap in the claw when it is closed. It is aggressive, and not only competes with native aquatic species for resources, but preys on them as well.

As always, the greatest resource in helping fight the spread of invasive species is you. We ask that you make sure any plants you introduce to your garden are not invasive and that you check your boat and gear for invasive hitchhikers before you launch.