By Howard Meyerson
Michigan’s trout fishing season opened April 26 on more than 1,400 rivers and streams. Add nearly 200 others open year-round, and by any account, there is a lot of water to explore.
Personally, I am ready. It’s been a long winter. I just need some cooperative weather. It’s hard to beat being out on rivers at this time of year.
But, what of this year with its crazy, cold weather, deep snows and spring flooding? Will the fishing be good? That’s a question state fish managers are waiting to answer.
Several biologists have mentioned the possibility that some trout populations may suffer a setback. Just which, how many, or how severely, is only speculation right now. Late summer surveys will shed light on the question.
But, past studies by Michigan DNR researchers have shown that trout fry, the newly hatched trout, are highly vulnerable to the conditions seen this winter and spring.
STUDIES SHOW HIGH STREAM FLOWS CAN WASH OUT YOUNG TROUT
“There is still a lot of snow in northern Michigan. If the snow melts rapidly and causes flooding, I would expect to see a weak year class produced in 2014,” DNR fish biologist, Brian Gunderman wrote me saying in early April when I contacted him. He is the former chairman of the state’s Coldwater Resources Steering Committee, a group convened by the DNR to hash out trout and salmon issues and regulations.
Gunderman referred to a 1994 DNR study conducted on the South Branch of the Au
Sable River. The research found no connection between winter severity and brown trout recruitment – meaning cold didn’t affect brown trout reproduction on that river. High stream flows, however, did.
“High stream flows during fry emergence (mid-March to mid-May for brown trout; mid-January to early May for brook trout) can reduce survival of young trout,” Gunderman wrote.
That is what some are thinking may occur on northern Lower Peninsula and Upper Peninsula waters this year, areas where the snowpack has been deep and melt was delayed.
“This year it’s been exceptionally cold. Marquette set a record for consecutive days below freezing,” explained Troy Zorn, fisheries researcher at the DNR’s Marquette Fisheries Research Station and new coldwater committee chairman. “The snowfall was average, but we didn’t have much melting, so the accumulation was high and we have fairly high flow conditions this spring. Those flows are hard on trout fry survival.”
What happens, he explained, is tiny trout fry have little reserve, or strength, to fight raging spring currents. And so, they may be flushed downstream and die. Extreme flows also can scour out spawning redds, eliminating eggs that would otherwise hatch.
Zorn and others will be looking to see how trout, salmon and steelhead were affected.
“Fry hatch and feed at a time of year when the fish are their weakest and flows tend to be high. That costs them more energy. If they can’t maintain it, and compensate for that flow, they lose energy and wash out,” Zorn said.
The verdict is likely to be a season coming.
NEW ONLINE TROUT STREAM DASHBOARD PLANNED
Meanwhile, Zorn and others have been working to develop a new online tool for trout anglers that will go public soon. Call it a Trout Stream Dashboard. The DNR site will have more than 40 Michigan “index” trout streams listed.
Anglers will able to look up a river and see what is trending. Are 2-year-olds abundant? Are trout populations rising or falling? The dashboard incorporates data collected during summer surveys. The work is funded by the Great Lakes Fishery Trust.
“Anglers will be able to look at individual streams and see growth and/or survival trends,” Zorn said. “It’ll have things like total brook trout abundance-per-mile, and the number of Age 0, or Age 1 trout, or brook trout over 12-inches.”
To be listed, each stream had to have natural reproduction – only wild fish. Each also had to produce a minimum of 50 trout during the survey. Zorn said the index rivers are representative of other streams in an area. Some are Michigan Blue Ribbon Trout Streams and others are not, but the fishing may be good.
Stream surveys to date show Lower Peninsula rivers have more trout than Upper Peninsula rivers. The winters down south are comparatively milder. They’re not quite as hard on trout populations. At least, that is the theory.
“Lower Peninsula rivers are pretty chock full of fish compared to those up here where the density of brook trout is quite low,” Zorn said. “My theory, especially on Lake Superior tributaries is, they get so much snow and run off, and persistently high flows, that it probably limits brook trout reproduction.”
If you’ve been holding tight, counting flies and spinners, waiting for the thaw, that is something to keep in mind when you go hunting for good trout streams this season.
This column appears on MLive Outdoors