By - Linda Gallagher

EXOTIC CRAYFISH A CULINARY DELICACY

If the fishing on your local lake or stream has slowed due to the warm temperatures and warm waters of the "dog days" of summer, consider trying another sport rapidly growing
in popularity with northern Michigan anglers-crayfishing.
Native to the Ohio River basin ecosystem, the large, bad-tempered crustaceans known in scientific circles as Orconectes rusticus, or rusty crayfish, is an exotic species in
Michigan accidentally introduced into the Great Lakes several decades ago.  Since then the species has spread aggressively.  In fact, said DNR Fisheries Biologist Dave Borgeson, from his office in Gaylord, "They’re
probably in most lakes and rivers of northern Michigan, introduced inadvertently by uninformed anglers who transported them to use as bait."

The shellfish have also brought Michigan a variety of ecological problems.  According to a 1995 study by the Minnesota Sea Grant program, the more aggressive rusty displaces other native species of crayfish, and destroys aquatic plant beds, vital to fish and freshwater invertebrates or food, shelter, and nesting areas.  Still unknown is what impact the rusties may have on spawning fish and eggs, although according to Minnesota researchers, the large crayfish, which grow up to 5 inches in length, have been observed attacking bluegills attempting to protect eggs on their spawning beds, and were observed actively feeding on lake trout eggs spawned on Lake Michigan reefs in November.  Also unknown is what effect the shellfish, which have voracious appetites, may have on invertebrates such as mayflies, midges and stoneflies, which in turn may affect food
supplies of many species of fish.

Identified by their large claws and distinctive rusty-colored patches on each side of the carapace, or mid-point of the body, rusty crayfish appear grayish-green in color most of the time, but acquire a bluish tint during the mating seasons.  Mature at a length of one and three-eighths inches, rusties grow quickly and have a lifespan of three to four years.  Capable of breeding during much of that time, the very prolific rusty crayfish, which has few natural enemies, mate anytime conditions are prime from early spring through early fall. After the mating act, the female will store the male’s sperm in her body until her eggs are ready to be fertilized, typically in late spring.  "It is important to note," said Jeff Gunderson, a Minnesota Sea Grant researcher, "that it is not necessary to have both a male and a female rusty to begin a new infestation in new water. Theoretically, it only takes one female carrying viable sperm to begin a whole new population."

In northern Wisconsin, the presence of rusties has reportedly become such an issue that some swimmers in heavily infested waters have stopped swimming because of the fear of being pinched by rusties mistaking human appendages for food.  With no research studies or surveys of the effects of the creature on Michigan’s aquatic ecosystems, state environmental experts are at a loss as to what can be done to control the growth of rusty crayfish populations.  But there is one thing we can do-we can eat them.

Although it is illegal in Michigan to commercially sell or transport rusty crayfish, anyone with a Michigan fishing license can catch rusty crayfish either on hook and line or in a
trap, something that Jeff Cullen, a resident of Central Lake, has done a lot of this summer on Intermediate Lake in Antrim County.   “Crayfish are one of the most sought after species of shellfish in the world, and are highly edible,” said Cullen.  “They’re a lot of fun to trap or catch, too, not to mention how they taste in a good jambalaya or etoufee.”  Using a simple minnow trap baited with chunks of ham or chicken placed in 2-5 feet of water, Cullen often catches dozens of the shellfish every night, when the rusties feed.  “There’s nothing to it, my grandkids love to help me, and I think there’s rusties in all of the lakes and streams around here,” he said.  “They’re very easily caught on hook and line, too, but we get more for the pot with the trap,” he grinned.

Rusty crayfish can be pursued anytime from early spring through late fall, Cullen says.  “But for me, it’s mostly something to have fun doing in the summer. I know there’s no way to slow down the effects they’re having on our waters, but I consider my crayfishing a form of management, just like hunting and fishing.”  If you find the fishing a bit slow the next time you head for your favorite lake or river, think about crayfishing instead. Chances are good that you and your family will soon be enjoying your own cajun culinary delicacy-northern Michigan style.