Walleye program in jeopardy at lake
The state Department of Game, Fish and Parks might stop its efforts to stock Lake Mitchell with walleye.
Todd St. Sauver, Sioux Falls-based regional fisheries manager for the GF&P, said recently that walleye stocking in Lake Mitchell may be suspended, based on research that shows past attempts have been ineffective.
He explained annual GF&P-conducted research shows the population of walleyes in the lake has generally remained even and has actually been below target levels over the past 10 years.
"It doesn't matter if we've been stocking or if we haven't," he said. "The populations basically stay the same."
Since 2006, Lake Mitchell has received a total of about 275,500 fingerling or large fingerling walleye -- which range from 1 to 10 inches -- in a process called stocking, which entails raising fish in a hatchery and releasing them in a body of water. The purpose is to add fish to build the population.
Dave Allen, a Mitchell resident and avid fisherman on the city's namesake lake, said he would be "extremely upset" if the stocking program gets suspended.
"That's the reason we have fish out there," Allen said. "If you don't keep stocking the lake, you won't have anything. It's completely stupid. If they're not going to grow the lake, you might as well pull the plug and drain it."
A 2012 GF&P report examining the lake over the past decade details an objective of establishing and maintaining a walleye population with a net catch per unit effort of at least five. A catch per unit effort typically is the amount of fish that are caught in a net in the lake for one day, but only once in the past 10 years has that number been higher than four.
Aside from netting, GF&P also has conducted fall electrofishing tests each year since 2008.
"We put electricity into the water and that temporarily stuns the fish, so we can net them after coming to the surface," St. Sauver said. "We collect them for data and then they eventually return to the lake."
St. Sauver explained electrofishing success is measured in catch per hour of juvenile walleyes, but he said the years GF&P has stocked the lake have not matched the successful years of the sampling method.
Lake Mitchell was not stocked with walleye in 2008 and had an electrofishing catch per hour of eight. In 2009, there were 67,500 fingerlings stocked with the catch per hour of 37. In 2010 and 2011, no stocking was conducted and the catch per hour was 50 and 25.
Perhaps most surprising was in 2012, when 67,340 fingerling were stocked and the catch per hour was one.
"Stocking is not a foolproof method," St. Sauver said. "Any stocking has the potential to fail. There are so many variables that impact fish survival at a young age."
In September, electrofishing catch per hour data was the highest it has ever been at 121 after the GF&P stocked 67,660 fingerlings in late June.
St. Sauver is unsure what causes the fluctuation in walleye population in the lake, saying various factors play a role.
"We don't know the answer why we don't have as good walleye populations in Lake Mitchell as we do in Lake Thompson or the Missouri River," St. Sauver said. "It has to be something related to the habitat in Lake Mitchell. There's some limiting factor that prevents it from having a walleye population similar to what people see in other bodies of water. It's important for us as managers to recognize that."
Ultimately, St. Sauver is the official who decides whether the lakes in the southeastern part of the state receive stocking. He talks with local anglers and also decides if the funding, which comes from fishing licenses, is having the desired effect.
If GF&P decides to stop stocking, Lake Mitchell will become reliant on natural reproduction for its walleye population.
"Stocking just because people want us to stock isn't a good enough reason," he said. "We need to be responsible with their money."
Ryan Rasmus, of the Blue Dog State Fish Hatchery in Waubay -- the hatchery from which Lake Mitchell received its most recent batch of walleye -- said the cost to purchase fingerling walleye is $59 per 1,000 fish. To put it another way, St. Sauver said, it took the purchase of about 126 resident annual fishing licenses at $28 each to cover the cost of the 2013 stocking of 67,720 fingerling walleye in Lake Mitchell.
Allen brought up the idea of having a local fundraiser to purchase fish to be stocked into Lake Mitchell. He's looked into the costs of privately purchasing fish for stocking purposes and said it is expensive.
"I would like the lake to get an order of fish every year," he said. "It's a no-brainer."