OutdoorMN News - Lake Sarah egg take finished for 2018, genetic experiment continues

[Rick]

Research continues into southern Minnesota’s premiere walleye fishery

For decades, Murray County’s Lake Sarah has been southern Minnesota’s premiere walleye fishery, but it could also hold the key to how Department of Natural Resources fisheries crews stock walleyes for decades to come in southwest Minnesota. 

DNR stocking programs are an important piece to the state’s overall fisheries management. It’s how DNR fisheries staff augment existing populations or help establish fisheries that didn’t previously exist. Fisheries crews introduce fingerlings, which are yearling fish that are just a few inches long, or newly-hatched fry to lakes throughout the state.

While many other lakes require stocking programs to enhance the fish population, Lake Sarah’s walleye fishery hasn’t needed outside help in more than a quarter-century. As anglers enjoyed reeling in walleye over the years, DNR scientists began investigating why this fishery supported itself while many others needed stocking to supplement the walleye population.

In the last decade, DNA testing revealed a unique strain of walleye genetics that were unique to Lake Sarah. Those genes can be traced back to the Waterville hatchery, which stocked Lake Sarah with walleyes from the Cannon River watershed and other southern Minnesota sources back in the late 1980s and early 1990s.

“We’re using this lake to hopefully create other fisheries just like Lake Sarah,” said Ryan Doorenbos, DNR Windom area fisheries supervisor. “This could be the key to self-sustaining walleye fisheries throughout the southern part of the state.”

That’s significant, according to assistant regional fisheries manager Brian Schultz, because a self-sustaining walleye population is preferable, especially in a region that was once thought to have scarce habitat suitable for natural walleye reproduction.

“Our stocking programs are important,” said Schultz. “But, natural reproduction is always preferred whenever possible, so if we have fewer lakes that require stocking, it’s an added benefit of cost savings each year.”

This year’s take on Lake Sarah yielded 136 quarts of walleye eggs during the first week of May. Those eggs were sent to the DNR fisheries hatchery in Waterville. While some of the walleye fry hatched there will be headed back to Lake Sarah, most of them will be used to augment the walleye populations in other southern Minnesota lakes, with the hope of creating a naturally reproducing walleye fishery elsewhere.

Fisheries crews take genetic samples of each walleye parent used in the Lake Sarah egg take. Those genetic samples will be compared to future generations of walleye brood in stocked lakes elsewhere, and will ultimately reveal whether the unique walleye strain is successful outside of Lake Sarah. While this is the fourth year DNR staff have used Lake Sarah walleye, anglers shouldn’t expect immediate results in another lake.

“It may be several more years, or even a decade before a significant walleye population is found elsewhere,” Schultz said. “A walleye is able to reproduce at three to four years old in the southern part of the state, so this is a project that will take some time.”

It’s still unknown exactly what’s behind Lake Sarah’s success, but the hope is that research will eventually reveal whether it’s a unique aspect to Lake Sarah’s aquatic habitat or simply a hardy trait hidden in the walleye strain’s genes. Either scenario will help DNR fisheries crews in their quest to create better walleye fisheries throughout the state’s southern region, which will also produce better opportunities for anglers, too.

For more about DNR’s work in the Windom area, visit the Windom area fisheries page.

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