May 10, 2012
Mention fish stocking to most Michigan anglers and the first species that come to mind are the cold–water fish – salmon and trout. But the Department of Natural Resources also expends significant time and resources stocking warm–water species, most notably walleye.
This year, the DNR has hatched out 18 million walleye fry from eggs taken at the Muskegon River and the Upper Peninsula waters of Lake Michigan. Some 7 million of them have been directly planted into lakes and streams as fry - days-old fish that are extremely vulnerable to predators and environmental disturbances.
The other 11 million have been hatched out and are raised to fingerling size (more than an inch long) and are stocked later in the spring. The fingerlings have a better chance of survival than fry. The drawback: growing them to size takes an additional step. Walleye fry are transferred from hatcheries to ponds where they grow to fingerlings.
The cost of maintaining and running the state's walleye ponds would be prohibitive if it weren't for the many partnerships the DNR has forged with sporting and conservation clubs across the state.
Although the DNR maintains some ponds on state-managed property, others are owned by third parties or other units of government. The DNR supplies the fry and the feed; volunteer organizations provide the labor needed to maintain ponds and grow the fish.
Fisheries Division's acting Lake Michigan Basin coordinator Jay Wesley said the department has been in the walleye-pond business for more than 40 years.
"If anything has changed, we've reduced the number of ponds that we had 20 to 40 years ago," Wesley said. "We learned which our best ponds were and we've focused on them."
The DNR has undergone staff reductions and, at the same time, club partners have experienced lower recruitment of members. Each year presents a new challenge to adequately staffing and managing the ponds, so Fisheries Division carefully determines the appropriate waters to stock.
"We've stocked walleye into virtually every river and lake in the state," said Wesley. "We now know the ones where it works and we're continuing with them, and we have discontinued the ones where it didn't work - or where natural reproduction is now sustaining populations."
Wesley said the volunteer groups are the key to the program.
"If it weren't for the volunteers we wouldn't have the size program we have," he said. "In Southwest Michigan, there are at least four different walleye-rearing ponds we could not operate without these walleye clubs helping us out. That's consistent throughout the state."
In the Southern Lake Michigan watershed, which Wesley oversees, walleye ponds are active in Belmont, Muskegon, Gun Lake, Union Lake and Comstock Park, Wesley said. All but two are owned by the DNR, the others by other municipalities.
Jim Baker, the fisheries supervisor for the Saginaw Bay Watershed, said the DNR has five active ponds in the management unit he oversees. One (which the DNR owns) is in Kawkawlin; two are municipality ponds in Auburn; and the other two are owned by clubs – the Arenac County Walleye Club operates one in Au Gres, while Walleyes for Iosco County operates one in Tawas City.
Kenny Rubis, a retired municipal employee, is the main man at the Arenac County Walleye Club. He says the 324-member club spends well in excess of $1,000 annually to maintain ponds and raise walleye for stocking.
Work begins in the fall when volunteers apply herbicide to the 8-acre pond, then plant wheat.
"In spring, we fill the pond from a drainage ditch, pumping 9 million gallons of water into it," Rubis said. "So we have the cost of running the pumps.
"Then we feed the pond with 30 50-pound bags of soy meal mix (provided by the DNR) to get the plankton going for the walleyes to feed on. When the DNR delivers the fry, we feed the ponds once a week, with 20 bags of soy meal the first week and then 10 bags the rest of the season. It takes six to eight weeks to get the walleyes up to size."
The DNR monitors the young fish until they are stocking size, at which point they are no longer feeding on zooplankton and must be relocated to prevent cannibalization. The club gradually drains the pond until the fingerlings can be corralled.
"We pull the water down to about 18 inches," Rubis said. "It takes about a week. The fish are caught in a net at the tube and we dip net them into 5-gallon pails. The pails are all weighed – that tells about how many fish we have.
"If we put 800,000 fry in there, we'll usually get about 400,000 fingerlings," he said. "But last year things just didn't go right and we wound up with only 35,000. Not good."
Fish are trucked by the DNR to inland lakes where they're stocked.
When Rubis' club first became involved, the fish were stocked into Saginaw Bay. Now that Saginaw Bay's walleye population has recovered – and natural reproduction is taking care of the future – the fish go elsewhere. Last year they were sent to the Cheboygan area, Rubis said.
That's fine by the club, he said. "It's a good cause."
Although last year showed poor production in the Saginaw Bay area – including one complete pond failure – Baker is optimistic the ponds will be back on track this year.
"Last year we produced 1.25 million walleye fingerlings," Baker said. "We had a poor year – one of our ponds went totally bust on us and we don't know what happened. We have the potential to produce significantly more if we have a good year."
Baker admitted, however, to being nervous about this year because earlier-than-normal warm weather caused an early spawn. The DNR was able to harvest eggs and hatch fry a couple of weeks early, but the weather cooled down and Baker is concerned that the normal growth of zooplankton in the ponds may have been slowed by the cold weather.
"Walleye rearing is a lot like farming," Baker said. "You never really know what you've got until you start to harvest them. I never count my walleyes until they're on the truck."
Sometime around Memorial Day, the DNR will know how the spring walleye ponds produced in 2012. One thing's for sure, though. Thanks to the dedicated and knowledgeable volunteer partners who, year in and year out, help to make it happen, the DNR's walleye-rearing effort is far stronger than it could ever be on its own.
Learn more about DNR-managed fish hatcheries at www.michigan.gov/hatcheries.