June 2022 - 23

" Before fish are stocked, we hand sort and
run the fish across a white plastic board. We
remove any plant fragments, tadpoles, snails
or non-target fish, " Campbell said.
It's a time consuming but vital process to
ensure the state's waters remain free of invasive
species.
Predators such as raccoons, kingfishers and
herons also pose a threat to fish in a hatchery.
" Ideally, we would have all of our fish in
buildings to protect them from predators, "
Campbell said. " But completely enclosed
buildings are expensive. Currently, only
a few of our facilities are set up this way,
while several have three-sided buildings and
others utilize bird netting over top of outside
rearing units. "
Humans are the final level of disease
and aquatic invasive species prevention at
a hatchery. Anyone who enters a hatchery
building must follow the facility's biosecurity
procedures, including using disinfectant foot
baths and hand-sanitizer stations at the doors.
" They may have just been fishing before
coming to the hatchery, or possibly wading
in a river that might be positive with
some type of pathogen that we don't want
introduced to the hatchery, " Alsager said.
Eggs are externally disinfected with iodine to minimize the possibility of infection by bacteria, fungi or parasites.
(Photo by Chris Martin/WGFD)
" So we ask them to use boot wash and hand
sanitizer stations before entering. " Education
is also important, and signs installed around
a hatchery alert visitors of the risks of
pathogens and invasive species.
The mere presence of people is stressful
for fish reared in a hatchery tank because
they have nowhere to hide from excited
onlookers. Campbell said some hatcheries
need to limit access to a certain area of
the facility to give sensitive or sick fish
protection from this stressor.
Preventing diseases and invasive species
from entering a fish hatchery is a round-theclock
job, and Wyoming's hatchery managers
hold a constant vigil to protect their charges.
Trading Wyoming's hatchery-raised trout for warm-water species such as walleye gives anglers a diversity of species
to pursue. But bringing fish into Wyoming from other states comes with the risk of introducing unwanted species.
Fisheries biologists sort through the fish and remove anything that doesn't belong. This involves gently moving the
entire load of fish across a white board one bucket at a time. The white background makes it easy to spot unwanted
organisms. These fingerling walleye came from Garrison Dam National Fish Hatchery in North Dakota a few years ago.
(Photo by Robin Kepple/WGFD)
" We're always alert to what's going on, " Alsager
said. " We are planners and strategists, and we
try to stay ahead of the next 'what-if.' But if
something does happen, we have a plan on
how to move forward. "
- Robin Kepple is the Wyoming Game and Fish Department's
education and information specialist for the
Laramie Region and is a regular contributor to Wyoming
Wildlife.
Wyoming Wildlife | 23

June 2022

Table of Contents for the Digital Edition of June 2022