LITTLE ROCK – The coldwater crayfish is a rare species found only in parts of the Arkansas and Missouri Ozarks. It inhabits big, spring-fed streams – namely the Eleven Point, Strawberry, Spring and South Fork Spring rivers. Several years ago, ringed crayfish from the North Fork White River basin, turned up in the South Fork.
University of Arkansas professor Dan Magoulick and his students have been studying this invasion where the coldwater crayfish has been displaced from much of the South Fork. The current theory is that ringed crayfish are more tolerant of low, summer water conditions, allowing them to out-compete the coldwater crayfish.
This ringed crayfish invasion is an example of a short-range introduction. A study published by the Missouri Department of Conservation found that short-range introductions of crayfish are more common than previously thought. Since several of Arkansas’s nearly 60 crayfish species are found in only a small portion of the state, this highlights the need to avoid moving crayfish around from one place to another.
The story of the coldwater crayfish is not all bad. Recent cooperative surveys by the University of Arkansas, Missouri Department of Conservation and Arkansas Game and Fish Commission have sought to better understand where coldwater crayfish are found and their population.
While they are mostly gone from the South Fork, coldwater crayfish populations are in fairly good shape in the Eleven Point and Spring rivers. They were only found in low numbers in a limited portion of the Strawberry River.