June 2022 - 21

IT STARTS WITH WATER
Fish do best in a healthy environment,
and a hatchery is only as healthy as its water
source. Water can become contaminated by
fish waste, diseased fish and outside influences
like grass, predators, water contamination,
organic build-up and more. It's important that
a water supply is tested regularly. Several Game
and Fish hatcheries have highly-meticulous
systems that use filtration and UV treatments
to reduce threats found in the water.
Goose Egg Spring supplies water to Speas
Hatchery and was covered in 2009 to fully
protect the water source.
" It would grow watercress, moss and algae,
and you could find frogs, fish and salamanders
in it, " Alsager said. " Protecting the hatchery
begins with its water source, and there's no
doubt we would have had a problem if we
had not covered it. "
Ground water sources often are saturated
with nitrogen, and too much can harm or
kill fish. One way Wyoming's hatcheries
combat this problem is through using vacuum
degassers.
" Water is pumped into these degassers and
is broken down into small droplets, which
increases the surface area. This allows for
nitrogen to be pulled off the water, " Alsager
said.
This process also removes oxygen, so lowhead
oxygenators are used to re-oxygenate the
water to the level fish need. The process allows
them to reuse the water.
Thousands of fish in a hatchery produce
a lot of waste, but dual drain circulars, drum
filters and other equipment effectively remove
the waste from the system. After the final use,
water is plumbed into a settling pond or tank,
which aids in the removal of suspended solids
before the water is discharged back into the
natural environment. Even this discharge of
waste water is done with the threat of diseases
and invasive species in mind.
" We want to prevent any animal from
getting into the effluent ponds and making
their way into a hatchery, " Campbell said.
" We typically elevate the effluent discharge
pipes 10 inches to a foot off the ground to
ensure there is no water-to-water contact with
outside water sources. "
Of course, what comes out of a fish is
dependent on what goes into it. To ensure
optimal health, Game and Fish gives highquality
food to its fish. That food is often in
The water from Goose Egg Spring at Dan Speas Fish Hatchery near Casper is saturated with nitrogen gas that causes
gas bubble disease in trout. To reduce the amount of nitrogen gas, the water that flows through the facility is pumped
through vacuum degassing towers. These towers strip excess gasses from the water. After flowing through the
degassing towers, nitrogen levels are reduced from 124 percent to less than 100 percent saturation. The water is then
re-oxygenated before being supplied to the eggs and fish. (Photo by Robin Kepple/WGFD)
baked pellets of various sizes. Alsager said
medicated feed can be used to treat infections
when certain diseases are detected in fish.
Any time fish are moved - from hatchery
to hatchery or stocked for anglers to catch -
there can be a risk of introducing or spreading
diseases and invasive species. Equipment used
in fish transfers, such as trucks, nets, buckets
and even employees' boots could become
infected.
" When we stock fish, if any equipment
comes in contact with water or mud, it gets
properly disinfected, " Alsager said. " If our
truck comes in contact with water, we disinfect
the truck - even the tires - to prevent
spreading diseases, " Alsager said.
Wyoming Wildlife | 21

June 2022

Table of Contents for the Digital Edition of June 2022