Today’s MI Environment story is taken from the State of the Great Lakes Report.
Overfishing. Habitat loss. Invasive species. Water temperature changes. All of these issues – and many more – make fisheries management a challenge in the Great Lakes for a group of fish called whitefish, which includes lake whitefish and cisco, also known as lake cisco. Collaborative work is underway through the Lakes Committees of the Great Lakes Fishery Commission to conduct research and find solutions.
Lake Huron. (Photo courtesy of MNR.)” src=”https://www.michigan.gov/egle/-/media/Project/Websites/egle/Images/OGL/2021-SOGL/Saginaw-Bay-Hydroacoustics-and-Trawling-3-9-2021.jpeg?rev=e8bb057d3fd0406aa8bcaf2cdc492b96&hash=E7302D1EF57F0688EB7A5E4B43B0C92B” style=”width: 50%; height: auto;”/>
Midwater trawl depth monitoring and hydroacoustic targets during a survey in Saginaw Bay, Lake Huron. (Photo courtesy of MNR.)
The Lake Superior Technical Committee and its member agencies have undertaken research to determine important factors in cisco recruitment dynamics. The cisco is an important commercial species in Lake Superior, but recruitment has been low and inconsistent in recent years. The agencies are engaged in lake whitefish acoustic telemetry work around the Buffalo Reef complex, an important lake whitefish spawning habitat threatened by encroaching stamp sands.
The Lakewide Assessment Plan (LWAP) is a collaborative effort among Lake Michigan resource agencies to improve consistency in data collection for lake whitefish and cisco. For example, standardized seine net surveys are conducted annually by agencies to index the abundance and growth of ciscos and lake whitefish of the year. Several more short-term targeted research efforts have been launched in recent years. Multiple surveys of nearshore zooplankton populations, larval emergence, growth, and feeding patterns have been funded in recent years with interest in the contrast of the two species. Controlled laboratory studies are also being conducted to further explore variation between the two species in foraging behaviors, preferences, and vulnerability to predation. Unique to lake whitefish, in-river surveys have been conducted to assess if there are any river spawning populations in Michigan. This will inform discussions on how best to incorporate riverine populations into management plans.
The Lake Huron Technical Committee is working to review and implement its lake whitefish research priorities. He embarked on a decade-long cisco reintroduction experiment and evaluation. Up to one million cisco fry are stocked each year in the vicinity of outer Saginaw Bay using northern Lake Huron populations as source populations. These stocks are assessed through assessments of existing fish communities, targeted sampling, and surveys of recreational and commercial fishers.
Although the habitat of western Lake Erie does not currently support whitefish year-round, its tributaries, including the Detroit River, have historically supported some of the largest populations of Great Lakes whitefish until recently. in the 1920s. Remnant populations of lake whitefish still exist, and the system still provides important spawning habitat for lake whitefish. Substantial 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 key native fish should pay off this decade with the revival of these remarkable fish. These efforts that benefit Michigan’s fish populations would not be possible without the efforts of many partners and funding through the US Fish and Wildlife Service’s Sportfish Restoration and State Wildlife Grants, as well as funds from the Great Lakes Restoration Initiative of the US Environmental Protection Agency. These conservation dollars are matched by funds from Michigan’s Game and Fish Protection Fund which is supported by fishing and hunting lic