Lake Superior herring numbers raise concerns
DULUTH, Minn. — Minnesota fisheries managers are concerned about the future of Lake Superior’s herring.
At a time when demand for the fish has increased, biologists worry not enough young herring are surviving, Minnesota Public Radio News reported.
Commercial fishermen who ply the waters off Minnesota’s North Shore have caught a lot fewer cisco, or lake herring, in recent years.
In 2011 and 2012, Minnesota commercial fisherman harvested more than 350,000 pounds of cisco each year. But in the last two years, that’s dropped below 250,000 pounds.
“I think there’s general agreement at least on the western arm of Superior that the population is not in a healthy state,” said Minnesota Department of Natural Resources fisheries chief Don Pereira.
Cisco are vital to both whitefish and lake trout, which eat herring or herring eggs to survive, Pereira said.
The fragile cisco population has led Minnesota fisheries managers to impose conservative limits on fishermen. But in Wisconsin, there hasn’t been any cisco limit.
The past decade has seen a surge in demand for cisco, especially the eggs, which are sold as cisco caviar.
In Wisconsin waters, mainly around the Apostle Islands, the annual cisco harvest has tripled since the early 2000s, to 1.5 million pounds in 2015.
After pressure from Minnesota and others, Wisconsin for the first time put a limit on its cisco harvest this fall. But that limit — 1.5 million pounds — is the same as what was harvested the previous year.
“We do not want to limit our commercial fishermen if there doesn’t appear to be a scientific need to do so,” said Terry Margenau, fisheries supervisor for Lake Superior for the Wisconsin DNR. “Having said that, this rule is designed to be reassessed every three years … to make sure we’re still where we want to be.”
Biologists around Lake Superior have recommended limiting the cisco harvest to between 10 percent and 15 percent of the estimated total biomass of cisco.
Wisconsin set its quota at about 7.5 percent, leaving an additional 7.5 percent to the Red Cliff and Bad River Bands of Lake Superior Chippewa, which have commercial fishing rights on Lake Superior. Minnesota sets its harvest more conservatively.
Cory Goldsworthy, the Lake Superior area fisheries supervisor for the Minnesota DNR, said the department sets its limits every year at an estimated 10 percent of the total biomass of cisco.
The Great Lakes Fishery Commission, which coordinates management among states, tribes and Canadian provinces, will evaluate whether Wisconsin’s plan is sustainable.