Rusty crayfish found in Lake Granby, invasive species could pose threat to Colorado River Basin

Rusty crayfish have been found in the Upper Colorado River Basin for the first time. That's according to Colorado Parks and Wildlife, which says the discovery in Grand County of the invasive species could potentially spell trouble for the Colorado River ecosystem.

The large crayfish were first found a month ago by a CPW team during a routine sampling in Lake Granby for nuisance species. That aquatic sampling was done near Sunset Point campground. Since then, more testing has been done that has recovered more rusty crayfish.

The CPW's Invasive Species Program says the freshwater crustaceans have previously been found in bodies of water west of the Continental Divide in Colorado, but this is the first time any lake feeding into the Colorado River has been known to have them.

"While finding any invasive species is detrimental to our state's aquatic ecosystems, finding rusty crayfish in Lake Granby, which feeds into the Colorado River, poses an even greater threat to the entire Colorado River Basin," said Robert Walters, the manager of the CPW program.

Rusty crayfish are normally found in the Ohio River Basin and it's believed they were illegally brought to Colorado by people who wanted to go fishing and use them as bait.

CPW is asking everyone to help stop the spread of the crustaceans. If you are going fishing, they remind you to never throw unused bait of any kind back in the water alive. Boaters and users of other watercraft are asked to always clean, drain and dry their gear if they are moving the watercraft from one body of water to another.

Rusty crayfish have also been found in the Yampa River and Catamount Reservoir. Other testing was done this month in nearby bodies of water and below the dam on the Colorado River but those samples didn't turn up any rusty crayfish.