Over 1 million fingerlings to come from Lake Mills

Correspondent

Lake Mills, Wis. Many lakes in Wisconsin rely on stocking to
keep fishing rods bent, so anglers will be pleased to know the Lake
Mills Fish Hatchery is doing its part, especially for walleyes. The
hatchery will stock about 1.1 million walleye fingerlings this
year.

That’s almost three times the walleyes the hatchery produced
just four years ago.

Since 1988, DNR hatchery supervisor Robert Fahey has managed
some 30 ponds, rearing tanks, and hatching jars on the station’s 75
acres, located about 30 miles east of Madison.

“If you could sum up the process of fish production, I would say
that balance,’ would be one of the key words to use,” he said.
“Everything is timing, and give and take.”

As far as balance goes, Lake Mills has been hitting it right on
the head in recent years, thanks in part to an inorganic fertilizer
program. Before 1998, with organic fertilizer, Lake Mills produced
about 400,000 walleye fingerlings during an average production
year. In 1998, they switched to inorganic fertilizer on a portion
of the ponds and the number went up to 700,000. Today, with the
same budget and workers, they are pushing out 1.1 million walleye
fingerlings per year.

“The fertilizer is used to help produce a particular type of
green algae. The green algae, in turn, is the primary food source
for microscopic organisms called zooplankton. The zooplankton are
an important food source in the pond that the walleyes will feed
on,” Fahey said.

“The inorganic fertilization program is just a more scientific
way of producing the food that the zooplankton and walleyes need.
The ponds are sampled and analyzed once per week, so we know what
we have to do to the pond to make it productive faster than when we
used organic materials. The Ohio DNR started the procedure, and we
just tweaked it a bit to meet our specific needs.

“There’s a lot of networking involved in the fish hatchery
process,” he said. “Statewide and nationwide, ideas are exchanged
to help make the procedure better and more economical.”

Timing is critical. It takes almost two weeks of care from when
walleye eggs are gathered and fertilized, to hatching. Walleye eggs
are gathered from Lake Delavan. When the fry reach 11/2 to 2
inches, almost two months are already invested in the fish. The
process of removing the walleyes from the ponds and putting them in
lakes takes just 21/2 weeks.

“You want the fish to be as large and hearty as possible before
they are put in a lake,” Fahey said. “But if our ponds become too
full, then that becomes counterproductive because there isn’t
enough food to go around for all the fish.”

Besides the 1.1 million walleyes raised for 2001, the Lake Mills
site also will produce 22,000 northern pike, 600 muskies and
414,000 coho salmon.

“We’re maxed out for every species we raise,” Fahey said. “If we
have a surplus in Lake Mills, we may send some fish up north if
they had a rough year. The whole propagation program throughout the
state is like a huge web.

“It’s not a competition between hatcheries. We produce what we
need to make Wisconsin’s fishing better.”