By Amelia Havanec
LANSING — Every fall, thousands of chinook and coho salmon return to northern Michigan rivers to spawn, counted at state collection sites in Manistee County and Traverse City.
But this year’s fishing season has its own set of challenges — a balancing act between weather and food supply has gone off-kilter — with fewer salmon as a consequence.
Chinook salmon. Image: Michigan Sea Grant
“From what we’re seeing, it’s looking like a pretty low year,” said Edward Eisch, the Michigan Department of Natural Resources (DNR) acting fish production manager.
Salmon fishing has been part of a 50-year saga since Pacific salmon were introduced to Lake Michigan in the mid-1960s.
To alleviate the environmental impacts of exotic and invasive fish in the Great Lakes, fisheries increased the number of Pacific salmon that would feed on rainbow smelt and alewives, according to Randy Claramunt, a DNR fisheries research biologist based in Charlevoix.
But as the numbers of smelt and alewives decreased over time, so eventually did the salmon.
“Since the mid-1980s the stocking of Pacific salmon across the Great Lakes have declined substantially and many lakes either reduced or eliminated the programs,” Claramunt said. “A lot of people have questioned the sustainability of the program in the future.”
But not many people would suspect that Great Lakes introduced salmon may fare better this year than those swimming in native waters across the country.
For example, this year’s drought in the West, combined with record hot weather, contributed to low river flows and warming waters, often too hot to support salmon and trout. The result is stressed-out fish more susceptible to diseases, according to a report by the U.S. Geological Survey.
“When you look at environmental factors like water temperature and water levels here, they play into salmon management like they do out on the West Coast, but they also play a different role,” said Claramunt. “For example, a very warm year we will see a good production of prey fish but then we’ll see less natural reproduction of salmon.”
The opposite scenario also has its consequences: In cooler and wetter years, prey fish numbers decline but natural selective traits of salmon improve because more salmon are fighting for the same prey.
It’s looking like a pretty cool fall ahead.
“We just completed the highest two-year water gain in recorded history,” says Drew Gronewold, a hydrologist for the National Oceanic and Atmospheric Administration based in Ann Arbor, Michigan. “What drove that surge is mostly related to a combination of really cold air and water temperatures, reduced evaporation, and periods of higher precipitation.”
January 2013 lake levels in Lake Huron and Lake Michigan set an all time record low.
“We saw the drop in natural reproduction in 2013,” Claramunt said. “People on average catch 2-year-old fish. So we knew this was going to be a bad year in fishing. But this creates opportunities to rebuild” balancing numbers between Great Lakes salmon and prey.
DNR fisheries research division manager Gary Whelan said, “Of course we’ve had to take measures on forage based issues for salmon in the Great Lakes also, which means reducing our overall stocking to make sure there’s sufficient forage for the number of salmon that are already out there.”
It’s too early to predict just how many salmon will be hitting the rivers this season. But a delay in migration, coupled with a dwindling food supply of alewife in Lake Michigan and Lake Huron, could indicate that there’s going to be a drop in numbers.
“As far as this year’s runs go, I can tell you that everything is late,” Eisch said “I attribute that to the consistently fair weather patterns that we’ve been experiencing.
“Generally speaking with Pacific salmon, they run best when you have low pressure fronts that come through and it’s cold and blowing hard out of the north,” he said. “That’s when they want to run the rivers, and we’ve just not had that yet this month.”
Commercial and sport fishing on the Great Lakes is a $7 billion business, according to the Michigan United Conservation Clubs. Salmon continually ranks as one of the most valued species in the region, along with lake trout, whitefish, perch and walleye.