Today’s MI Environment story is from the State of the Great Lakes report.
Overfishing. Habitat loss. invasive species. changes in water temperature. All of these problems – and more – make fisheries management in the Great Lakes a challenge for a group of fish called coregonines, which includes whitefish and cisco, also known as sea herring. The Great Lakes Fishery Commission’s lake committees work collaboratively to conduct research and find solutions.
Midwater trawl depth monitoring and hydroacoustic targets during a survey in Saginaw Bay, Lake Huron. (Photo courtesy of DNR.)
The Lake Superior Technical Committee and its member agencies conducted research to determine factors important to Cisco’s hiring dynamics. Cisco is an important commercial species in Lake Superior, but recruitment has been low and inconsistent in recent years. Agencies are studying acoustic telemetry of whitefish around the Buffalo Reef complex, an important sea whitefish spawning habitat threatened by invading stamp sands.
The Lake-Wide Assessment Plan (LWAP) is a collaborative effort by the Lake Michigan Resource Agencies to improve data collection consistency for both Lake Whitefish and Cisco. For example, standardized seine surveys are conducted by agencies each year to index the abundance and growth of juvenile cisco and sea whitefish. Several shorter-term targeted research efforts have been initiated in recent years. In recent years, several studies of coastal zooplankton populations, larval emergence, growth and feeding patterns have been funded to contrast the two species. Controlled laboratory studies are also being conducted to further investigate the differences between the two species in foraging behavior, preferences, and susceptibility to predation. Unique to lake whitefish, river surveys were conducted to assess whether river spawning populations exist in Michigan. This will stimulate discussions on how best to integrate river populations into management plans.
The Lake Huron Technical Committee is beginning to review and implement its whitefish research priorities. It has begun a decades-long reintroduction experiment and evaluation by Cisco. Up to one million juveniles are kept annually near outer Saginaw Bay using the northern Lake Huron populations as source populations. These stocks are evaluated through assessments of existing fish communities, targeted sampling and surveys of recreational and commercial fishermen.
While the western Lake Erie habitat did not support year-round Coregonids at the time, its tributaries, including the Detroit River, historically hosted some of the largest populations of Coregonines in the Great Lakes in the 1920s. There are remnant populations of sea whitefish and the system still provides important spawning habitat for sea whitefish. Significant efforts have been made to restore reef spawning habitat that has been lost to development over the past century. This renewed interest in a group of important native fish is expected to pay dividends this decade with the revival of these remarkable fish. These efforts, which benefit Michigan’s fish populations, would not be possible without the efforts of many partners and funding from the US Fish and Wildlife Service’s Sportfish Restoration and State Wildlife Grants, along with funding from the US Environmental Protection Agency’s Great Lakes Restoration Initiative. These conservation dollars are supplemented by monies from the Michigan Game and Fish Protection Fund, which is supported by fishing and hunting licenses