Mention Black Lake (Cheboygan and Presque Isle counties) to many Michigan anglers and the first thing that pops into their heads is lake sturgeon.
There's a good reason for that, Black Lake has a highly publicized spear fishery through the ice that draws both anglers and observers. But in terms of angling effort, Black Lake is really a walleye/northern pike/muskellunge lake, says Michigan Department of Natural Resources fisheries biologist Tim Cwalinski. And that's been a focal point for management.
"Black Lake's walleye fishery has historically been supported by wild recruitment," Cwalinski said. "It hadn't really been significantly stocked for a hundred years. If you caught a walleye out of there, it was a wild fish.
"With wild fish you get population fluctuations," he continued. "You get good year-classes and you get poor year-classes, but usually good year-classes are strong enough to carry the population through the weaker ones."
But about a decade ago the DNR started hearing from walleye anglers they were concerned about the fishery.
"The general tenor was all the same," he said. "Anglers said they were catching a few larger walleye but weren't catching any sub-legal fish (less than 15 inches). We did a population estimate survey in 2005 and the bottom line was we caught right around 1,000 walleye and only five of them were less than 15 inches.
"So what we saw was identical to what anglers were telling us ? the angler reports were similar to what we saw in the survey. In the 2005 survey the population was one walleye per acre and it was an adult. This is a sign of an unstable population."
Fisheries biologists think the lake's colonization by zebra mussels had something to do with it. Black Lake (so named because the tannic acid stained the water dark) cleared up considerably in recent decades as demonstrated by water clarity and nutrient monitoring overseen by the Tip of the Mitt Watershed Council.
"Walleye don't seem to do as well in clear lakes as they do in darker lakes," Cwalinski said. "When walleye fry hatch, they need a lot of zooplankton (and the right size and types of zooplankton) for early growth and survival. We hypothesized that zebra mussels really impacted that lower food chain. If that plankton's not there, we're going to have bottlenecks with wild walleye recruitment. It wasn't an issue with adults spawning; it was most likely linked to survival of wild fry following the absorption of their yolk sac."
Cwalinski said the DNR devised a plan to stock up to 200,000 spring walleye fingerlings in the lake annually for three out of five years, then sit back and see what happened.
"Spring fingerling walleye are past the plankton-eating stage when they're stocked," Cwalinski said. "These two inch fish are eating other species such as perch and sucker fry that are smaller than they are. We stocked three years in a row. And the lake association was stocking, too, with fall fingerlings. This was a plan we worked on cooperatively with the Black Lake Association and lake anglers, to accomplish these dual stocking efforts. We thought that maybe if we could re-build a large spawning stock based on 3-4 year classes, that eventually these adults could inundate the Black Lake system with eggs and jump start wild recruitment again. Natural food for walleye fry might still be limiting of course, but flooding the system with enough wild fry might ensure survival of enough fish to build future wild year classes."
DNR Fisheries Division conducted subsequent fall juvenile assessments from 2010 to 2012 that showed good survival of the state stocked fingerling walleye. Cwalinski said all the young walleye they examined in two of the three years (five- to seven-inch fish) had been marked with oxytetracycline which showed they were DNR hatchery fish.
"Wild fish recruitment is still failing, but survival of our spring-fingerling walleye is good. And anglers are now saying we're catching encouraging numbers of sublegal fish again."
That doesn't mean, however, that Black Lake will necessarily be dependent on stocked walleye forever.
"Now there's a bunch of 1-, 2- and 3-year-old fish in the lake," Cwalinski said. "As those fish become 4-, 5-, 6-, and 7-years-old, hopefully, there will be enough of them that they'll produce so many fry that it'll increase natural recruitment. If not, we are prepared to supplement Black Lake in the future periodically with stocked fish, as long as statewide production remains good."
"We just didn't have enough adults to produce a good year-class," he continued. "It's not a mystery. But factors such as low zooplankton levels are out of the DNR's control and could be a lingering problem into the future. We just don't know yet."
Cwalinski said anglers are catching big pike and they've got 10-inch walleye in their stomachs. This suggests young walleye are abundant in the lake right now, good news for future walleye anglers.
"Black has always been the best pike lake up here in the Inland Waterway region. There's good vegetation, more than in a lot of other lakes, and there's always a possibility for a 40-inch northern. Legal-size pike in the 24- to 32-inch range are not uncommon."
Smallmouth bass fishing has always been good and Cwalinski thinks it'll only improve with the water clarity. As for perch, the growth rate has been slow for many years. A burgeoning walleye population might thin those out and lead to better perch fishing because of better growth rates.
And Black Lake remains the premier muskellunge fishery in the northeastern Lower Peninsula, Cwalinski said. It supports a popular spear fishery through the ice and rod-and-reel fisheries in the lake and in the lower Black River during the open-water season.
Black Lake remains an important lake to DNR fisheries managers. We have developed a strong cooperative relationship with the lake association and a wide array of anglers on the lake, and hope to foster this relationship further into the future. Angler reports are essential for future management, especially since the DNR won't be able to survey the fish populations annually. The Burt, Mullett and Black lakes corridor are key angling and recreation-driven locations in the northern Lower Peninsula. Each lake has its angling promise and potential. Rebuilding the Black Lake walleye population is one goal in this promise.