Fishery biologists from the Services LaCrosse and Ashland Fishery Resources offices, and Genoa National Fish Hatchery, Wisconsin, will trawl to collect as many as 1,000 round gobies in Calumet Harbor and the Calumet River.
Biologists plan to use the gobies in tests to determine the sensitivity of this species to several fish toxicants, which may be used to enhance efforts to curb the advance of the goby. Biologists say there is an urgent need to control the movement of the non-native goby from Lake Michigan into the Mississippi River via the Illinois Waterway.
"Round gobies have already spread around the Great Lakes, and are threatening to move into major river systems, much like the zebra mussel did," said Pam Thiel, Project Leader with the Services LaCrosse Fishery Resources office in Wisconsin. "This effort is part of a multi-faceted program to try to stop these fish from getting into the Mississippi River system. Once theyve made it that far, we may not be able to stop further spread."
Thiel said gobies collected on Tuesday will be taken to the Upper Mississippi Science Center, operated by the U.S. Geological Survey in LaCrosse, Wisconsin. There, studies will be conducted to determine the sensitivity of the goby to several fish toxicants.
The toxicant study is undertaken by the Service in a joint effort to establish an electrical barrier that would prevent gobies and other non-indigenous fish from moving from the Great Lakes to other ecosystems. The feasibility of the electrical barrier is being studied at the U.S. Geological Surveys Great Lakes Science Center in Ann Arbor, Michigan. Fish toxicants may be used in evaluating the effectiveness of an electrical barrier if one is placed in the Chicago Waterway. Use of toxicants would help biologists control the movement of gobies through the barriers.
Round gobies first appeared in North American waters in 1990 in the St. Clair River between Lake Huron and Lake Erie. A native of the Black and Caspian seas, gobies probably were transported in ballast water of ocean going ships, which eventually discharged their ballast in the Great Lakes. Gobies have since spread from the St. Clair and Detroit rivers and have been found in waters from Lake Superior near Duluth, Minnesota, to Clevelands Grand River on Lake Erie. Gobies were first spotted in the Chicago area in 1993 in the Grand Calumet River.
Gobies pose several serious threats to native fish species, Thiel said. They are aggressive, often out competing native fish for food, living space, and spawning areas. Voracious feeders, gobies eat the eggs and young of native fish, and have already begun to affect indigenous Great Lakes species such as the mottled sculpin. If allowed to spread into the Mississippi River system, they will cause declines in native fish such as darters, sturgeon, logperch, and some species of minnows.
Round gobies are bottom-dwelling fish that grow to about 10 inches in length. They survive well in degraded water quality and can feed in low light or complete darkness, giving them an edge over native species. In addition to their impacts on aquatic communities, gobies often frustrate anglers by stealing bait meant for more desirable sport fish.
The U.S. Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 93-million-acre National Wildlife Refuge System which encompasses more than 530 national wildlife refuges, thousands of small wetlands and other special management areas. It also operates 66 national fish hatcheries, 64 fishery resource offices and 78 ecological services field stations. The agency enforces Federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign governments with their conservation efforts. It also oversees the Federal Aid program that distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies. For further information about the programs and activities of the U.S. Fish and Wildlife Service in the Great Lakes-Big Rivers Region, please visit our home page at: http://midwest.fws.gov
