A study to see if artificial structure placed in rearing ponds improves growth rates and hardiness of muskies is being conducted at the Wild Rose Fish Hatchery. Pieces of “structure” made from scrap vinyl was bought for the Wild Rose rearing ponds by the Winnebagoland Musky Club, a matching grant from the Hugh C. Becker Foundation in Minnesota, and a donation from the family of the late Mike Primising, a former fish biologist in Waushara County.
Steve Fajfer, DNR hatchery supervisor at Wild Rose, said the idea for the study came about after renovations were made at the hatchery. The local soil is sandy and water drains quickly through it. New rearing ponds at Wild Rose had to be lined with plastic to hold water. The liners also made the ponds easier to clean, but the ponds resembled large swimming pools with a sterile, unnatural look.
“It’s great for efficiency of water and fertilization and harvest,” Fajfer said. “We can disinfect it. It’s a really great situation. But when we started putting muskies in the ponds we noticed that they seemed to be uncomfortable. Muskies like to have structure nearby. If you saw a bit of grass floating on the surface, muskies would gather around it. Then you would see muskies gathered around each other simply because it was something to sit next to.”
Fajfer reasoned that in a natural setting, muskies would have weeds, rocks, trees, or other cover to which to relate.
“We wondered if having some type of structures in the pond would be beneficial to muskie survival and growth,” he said.
Fajfer said a major concern about adding structure to the ponds was biosecurity. In the past, old Christmas trees or something similar would have been placed the ponds. These things eventually would decay and contribute to fungus and bacterial growth that is unacceptable in the small environment of a rearing pond. Read on….