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On the Job
CSI (Carp Scene Investigation) Five things to know about hunting aquatic invasive species.
TIFFANY HICKOX: “If I wasn’t monitoring the fish, it could potentially ruin the rest of the Great Lakes and rivers.”
By Sarah Colburn | Photograph by Roee Dori
ZEBRA MUSSEL ASIAN CARP Origin: First brought to the United States from China in the 1970s by Arkansas fish farmers to improve water quality by removing algae from fish production ponds. They escaped from the fish farms and began to appear in the southern Mississippi River in the 1980s. They have been moving north at a rate of about 50 miles per year and have been found in the St. Croix River. Impact: Bighead and silver carp are filter feeders, straining tiny animals and plants (plankton) out of the water. They directly compete with native filter feeders such as mussels and fish, which can potentially disrupt the entire food web in a water body. Leaping fish can also be hazardous to boaters. 18 Initiative Quarterly Magazine
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Origin: Native to Eastern Europe, they were brought to North America as larvae in ballast water of ships that traveled from fresh-water Eurasian ports to the Great Lakes. By 1991, the mussels had made their way into the Mississippi River via the Illinois River. Impact: Zebra mussels encrust native mussels, and ultimately smother them, which has caused significant declines in native mussels on the Mississippi River. They strain the same plankton from the water that young native game fish and native mussels depend on for food. This past summer, researches found 1000 zebra mussels per square foot covering the bottom of Lake Mille Lacs—73 times more than the previous summer. Zebra mussels have also been found in the St. Croix river below Stillwater. SOURCE: WISCONSIN DEPARTMENT OF NATURAL RESOURCES