Chinook stocking feedback sought
How many more salmon and trout would it take to improve catch rates and appease anglers? How many fish can the lake support and remain “healthy?” How many are too many that would deplete the forage base and risk collapse of the fishery? And is the Lake Michigan lake trout rehabilitation plan all but dead?
These are the leading questions facing fisheries managers around Lake Michigan as agencies review their salmon and trout stocking programs for coming years.
In Wisconsin, Department of Natural Resources officials held meetings in early September and offered two proposals for adjusting the agency's stocking strategy for 2020 and beyond.
Both included increases in chinook salmon, the species favored by many charter captains and other anglers but also with the most significant impact on the lake's vulnerable forage base.
Both also suppressed the level of brown trout, the fish with the greatest benefit to shore and small boat anglers, well below the standard set in previous decades.
And both included further cuts to lake trout.
The options were laid out in meetings Sept. 3 in Green Bay and Sept. 4 in Milwaukee.
The gatherings represented the most recent step in what has become a challenging balancing act for the Lake Michigan fishery managers.
The Lake Michigan salmon and trout fishery is a matter of large importance economically, as it (combined with Lake Superior) generates $185.4 million dollars in economic activity per year, according to state figures.
And it looms large culturally, too, since it's been a part of life in harbors on Wisconsin's east coast for generations.
With the exception of chinook in Michigan streams and lake trout in some areas, the modern salmon and trout fishery is largely one of put-and-take and is supported by sales of fishing licenses and Great Lakes salmon and trout stamps.
Since the lake trout, the lake's native top predator, was decimated in the early to mid 20th century by invasive sea lampreys and other non-native fish such as the alewife flooded in, Lake Michigan has been significantly altered.
Beginning in the 1960s, fisheries managers were able to make the best of a bad situation by stocking non-native salmon and trout that gobbled up the alewives and created a thriving sport fishery.
However, the last three decades have been marked by the invasion of zebra and quagga mussels, filter-feeders that have ravaged the base of the food chain.
As a result, most forage fish have struggled to reproduce. Scientists have documented general declines of prey fish, highlighted by an all-time low of alewife of 0.02 kilograms/hectare in 2017, according to an annual assessment by the U.S. Geological Survey.
Fisheries managers responded over time with stocking cuts, including a 33% chinook stocking cut in Wisconsin waters of Lake Michigan in 2013 and 50% or greater cuts in brown trout and lake trout in 2017.
The changes likely contributed to a slight rebound noted in the forage base last year as well as substantially bigger sizes in predator fish caught by anglers and returning to weirs.
The DNR reported the average weight of 3-year-old female chinook salmon captured lake-wide in 2018 was 20.6 pounds, highest on record dating to 1986.
And the standard weight of 35-inch chinook last year was 17.5 pounds, above average over the last three decades.
The biomass of alewife increased to 0.54 kilograms/hectare in 2018, up from 0.02 in 2017. And the total prey fish biomass was 6.22 kg/ha in 2018 compared to 3.77 in 2017.
The 2019 forage base data are not yet in, but the size of fish caught by anglers this year was among the heaviest in most anglers' memories, indicative of good food availability.
But catch rates have been below average, even by experience charter captains.
The lake-wide catch of chinook salmon by charter boats fell to 52,512 fish in 2018, the fourth consecutive decline, and is now just 25% of the harvest seen in 2012 and 50% of the average catch since 1990.
The combination of heavier fish but lower catches had most attendees at the Sept. 4 meeting in Milwaukee asking for increased stocking rates, almost exclusively of chinook.
About 50 anglers and charter captains attended the gathering at the UWM School of Freshwater Sciences.
Brad Eggold, DNR Lake Michigan fisheries supervisor, said the plan for 2020 was largely set, since all species but chinook were already in the hatchery pipeline.
Notably, the agency already has planned for an increase in chinook stocking in 2020, from 810,000 this year to 1 million next year.
All other species were held level in the 2020 plan: coho salmon at 400,000, brown trout at 376,000, steelhead at 350,000, lake trout at 300,000, and rainbow trout (Arlee strain) at 100,000.
For 2021, Eggold laid out two scenarios, both with additional increases in chinook but one which also would also bolster other species.
In the first, chinook would be increased to 1.11 million and all other species would be held at the 2020 level except lake trout, which would be slashed to 45,000.
The second would feature a more modest increase in chinook stocking to 1.04 million and bump up coho to 500,000, browns to 450,000 and steelhead to 410,000. It would also cut lake trout to 45,000 and Arlee rainbows to 50,000.
The two proposals were only suggestions, Eggold told the crowd.
Most of the comments were in favor of even larger increases.
Dan Welsch, who runs Dumper Dan's Sportfishing Charters in Sheboygan, said his boats this year landed 13 chinook that weighed 30 pounds or more, a record high in his 30-plus years of charter experience.
That was the good, Welsch said. On the other side of the coin, he had a number of charter boats get skunked over Labor Day weekend.
“August and September are terrible now,” Welsch said. “We have lower returns of kings to our shores and harbors because we're stocking less, and all the fish in the lake have been caught.”
Jason Woda, owner of Reel Sensation Charters in Milwaukee, suggested larger increases to chinook stocking than the DNR had outlined, beginning this year.
And Jim Buss, a sport angler who lives in Cudahy, said he thought the chinook stocking should go up to 1.2 million immediately.
The prevailing sentiment at the meeting was decidedly pro-chinook. Only a few comments were made in favor of brown trout or other species.
And no one voiced support for the decades-old Lake Michigan lake trout rehabilitation program led by the U.S. Fish and Wildlife Service. The native top predator has shown signs of natural reproduction in parts of the lake. But without continued stocking, it's unknown if the recovery will continue.
Those motivated to come to the Milwaukee meeting made it clear: Most of them prefer chinook to lake trout, and they would like to see higher stocking rates of the salmon.
“It comes down to risk management,” Eggold said. “The higher you go with stocking the riskier it gets.”
The equation includes one substantial wild card, natural reproduction of chinook in Michigan rivers. Last year, about 65% of chinook caught in Lake Michigan were naturally reproduced.
If chinook reproduction were to spike, it would put additional predation pressure on the forage base. Fisheries managers are trying to prevent a collapse of the fishery as occurred in 2005 in Lake Huron.
Eggold said the agency will include public input as it crafts its plan for the next chapter of the salmon and trout fishery.
The DNR expects to make its final 2020-23 stocking decisions over the next two months.
To provide input through Sept. 30, send the DNR comments by email at dnrlakemichiganplan@wisconsin.gov or mail at Brad Eggold, 600 E. Greenfield Ave., Milwaukee, WI 53204.