June 2023 • Nebraskaland 51
Research is showing that walleye stocked as fi ngerlings might have higher survival rates than fry in
Lake McConaughy. ERIC FOWLER, NEBRASKALAND
have the best chance of survival.
In 2017 and 2018, immediately after
walleye were stocked, UNK researchers
and Game and Parks biologists
collected predator fi sh in areas where
walleyes were stocked, as well as
elsewhere in the lake, to determine
what species were present where. The
stomachs of those fi sh were pumped to
determine what they had been eating,
and then they were released back into
the lake. Researchers found every
predator in the lake was feeding on
young-of-the-year walleyes, and those
fi sh were most abundant in the middle
and lower reaches of the reservoir.
For the second part of the study,
researchers focused on what
young walleye primarily eat: small,
aquatic microorganisms, known
as zooplankton. They sampled 48
locations along the north and south
shore of McConaughy when walleye
were stocked in 2018 and found
zooplankton size and availability
varied by month and location. This is
signifi cant because previous studies
have shown fry will select smaller
species of zooplankton and fi ngerlings
will select larger ones.
A third piece of the research
focused on water clarity, another
important factor to walleye fry and
fi ngerling survival based on previous
research. Juvenile walleyes prefer
depths between 3 and 9 feet where
water tends to be more turbid. In
these conditions, they can see better
than other fi sh because of their eye
structure, and the turbidity can serve
as a cover, protecting them from other
sight-feeding predators. In 2018,
researchers measured water clarity at
locations throughout the lake when
walleye were stocked. Researchers
