RANGELEY — The Rangeley Lakes Heritage Trust is continuing its investigations into the invasive rusty crayfish this summer.

The focus will be on determining how far they have traveled along the shoreline.

“Unlike other organisms in the lake, crayfish must literally crawl to expand their populations,” said Amanda Laliberte, Headwaters Lake Protection Program manager for the Heritage Trust.

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 in the Rangeley Lakes Region. This project is part of an ongoing effort to gain a clear picture of crayfish populations across the state and to determine how far the invasive rusty crayfish has spread in Maine.

The first season staff and volunteers collected crayfish in every body of water in the region to see if rusty crayfish were present, Laliberte said. 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.

The rusty crayfish is an invasive species most likely introduced 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.

The Rangeley Lakes Heritage Trust maintains traditional public access and uses of its land for recreation, education and scientific study. It also offers a summer youth program, maintains a water quality program, and offers remote and traditional camping through its social enterprise, Cupsuptic Lake Park & Campground.

To learn more about Rangeley Lakes Heritage Trust or how to get involved, visit www.rlht.org.