Concerns over alewives, salmon spawn debate
A lot of eyes are focused on this year’s salmon spawning run, and plenty of ears await word on just when it’s time for a trip to a favorite lakeshore river.
But it’s the mouths — or in many cases in this digital world today, the fingers — than are already running with rumors of Lake Michigan’s salmon fishery in jeopardy of failing.
That’s exactly what happened in Lake Huron more than a decade ago, when chinooks basically ate themselves out of alewives, then starved or migrated out of Huron into Michigan in search of their favorite forage.
For nearly as long, newspaper reporters in Michigan and Wisconsin have retold the tale, and wondered, in print, if the same thing could happen in Lake Michigan.
While the obituary is premature, there are enough red flags that even many former skeptics are concerned over the future of chinook salmon here.
The reason? Alewife numbers have been at very low levels for a number of years, and researchers are finding fewer year classes of them out there.
The late Paul Peeters, a longtime DNR fisheries biologist and avid salmon and trout angler from Sturgeon Bay, was among the first to sound the alarm.
More than a decade ago, Peeters warned that declining weight and fat content of chinooks was a sign that they weren’t getting enough to eat, and he recommended stocking cuts.
His calls for reduced stocking were eventually heeded by Wisconsin, but Michigan didn’t follow suit and instead, raised even more chinooks for a period before eventually cutting and finally, in 2013, took the largest share of a lakewide slashing of salmon stockings.
Today, some stubborn anglers still insist there are plenty of alewives, and the DNR simply needs to stock more salmon to revive the fishery.
They got a little ammo prior to this year after a very strong alewife year class in 2010 helped revive salmon sizes for a few years, and the 2012 class of alewives was also above average. However, researchers say the 2013 and 2014 alewife year classes were poor, and early reports are that 2015 is only slightly better.
Reduced forage has shown up in fish size. Only 27 chinooks over 20 pounds were registered in this year’s K/D Salmon Tournament, a drop of more than 80 percent from 2014.
More wild fish
A lakewide coded wire tag study on hatchery chinooks has shown that a longtime hunch was correct — naturally reproducing salmon were entering the lake at an unprecedented rate.
While most are coming from the Michigan side, some also migrated from the Ontario side of Lake Huron.
Even with about six of every 10 fish caught in recent years wild, biologists estimate the salmon population is down about 75 percent from 2012, a combination of reduced stocking and a drop in natural reproduction from low, warm water that year.
While that sounds like a bad thing, the fact that it’s coinciding with a dangerously low period of alewife numbers gives hope to the faithful who have seen salmon pronounced dead before.
The first time was the late 1980s, when alewives crashed from record salmon stocking in the mid-80s. Stocking cuts helped restore balance and improve fish health. There have been more cuts since then, including in the mid-00s when salmon size shrunk dramatically.
David Warner, a research biologist with the Great Lakes Science Center in Ann Arbor, Mich., said long, cold winters and cold springs in 2013 and 2014 didn’t do alewives any favors, and though it was warmer this year, the jury is still out on whether there were enough alewife produced to sustain even a reduced population of chinooks.
Unlike trout, which have been known to feed on round gobies on the bottom at times, salmon prefer foraging in open water on schools of alewife.
The number of young alewives was up slightly during August surveys, but Warner said there were far fewer adults, a sign that salmon and trout may be eating themselves out of large portions of year classes.
Researchers did find more young-of-the-year bloater (chubs) than they’d seen in more than 20 years. He wonders if anglers might be finding any in the bellies of salmon or trout. (They look similar to young alewives, but have an adipose fin).
It’s likely that most of the fish fanatics invading the Besadny fisheries facility Saturday won’t have a clue what’s going on in Lake Michigan. Yet an hour south, salmon and alewives will be a hot topic at a Lake Michigan Fisheries Forum meeting at Lakeshore Technical College.
In the end, all that any of us can do is wait to see how this all shakes out.
Learn more on the delicate predator/prey relationship at http://content.govdelivery.com/accounts/MIDNR/bulletins/11c4f0e
Kevin Naze is a freelance outdoors writer. Email him at [email protected].
This article originally appeared on Green Bay Press Gazette: Concerns over alewives, salmon spawn debate