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My name is Hayley Glassic.
I'm a Masters Student in the [INAUDIBLE] Lake Ecology Lab
at Utah State University in the Department of Watershed
Sciences.
And I research fish and aquatic ecology.
The goal of my research is to determine
if drought-driven lake level declines have impacted habitat
for two species within Bear Lake, one
being the Bear Lake sculpin, which is a small forage fish,
and the other being the Bear Lake strain
of the Bonneville cutthroat trout, which
is one of the large trophy sport fish of the lake.
The Bonneville cutthroat trout in the Bear Lake population
is one of the main sources for the brood stock
or the eggs and milt that are used
to make many of the other populations
throughout the state itself.
Because the fish is unique and recognizes its own strain,
it's also a species of concern for the State of Utah.
Years when the lake levels are high,
the trout are able to spawn in the tributaries.
So the tributaries are completely connected
to the lake itself.
There is enough flow in the tributaries
so that the Bonneville cutthroat are cued to move up the stream.
And then they're able to make it back safely
into the lake itself.
Bear Lake, right now, is close to full capacity.
It hasn't been this high in the past 20 years.
In low water years, the lake can become completely disconnected
from the tributaries themselves.
And this is a problem for the Bonneville cutthroat trout
because they may not be able to access the tributary at all
during their spawning season.
If they are able to access it, they
are often imperiled because of predation by large birds,
such as the American white pelican.
And if they actually make it up into the tributary,
it could be possible that their eggs or larvae are
unable to make it back into the lake
to complete their life cycle.
So today we were in the spawning trap
on Swan Creek, which is one of the main spawning
tributaries of Bear Lake.
What we're doing is we're capturing the Bear Lake
Bonneville cutthroat trout as they're moving
to their spawning grounds.
When the fish first come into the trap,
the Utah Division of Wildlife Resources biologist
first weighs and measures each fish and determines its sex.
Then we anesthetize the fish to keep them safe
as we handle them.
Then the fish is given to another UDWR biologist which
takes its eggs or milt to create fertilized
eggs for the hatcheries.
Then it finally comes to me, where
I weigh and measure the fish once again
to make sure I have accurate data as well.
And then I insert a tag into the fish.
Passive integrative transponder tags or PIT tags
are used in order to recapture fish.
And it's very similar to what you actually put in a dog
or cat at the vet's office.
So once you go to the vet, they can scan the tag.
And each tag has an individual number
that is identifiable to that specific animal
or, in this case, the specific fish.
Because we're using these specific tags,
we can get measurements such as growth and weight over time
as we recapture them.
And largely, we can create models
in order to estimate how much survival is happening
within the population and how healthy the population is
as a whole.
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The Bear Lake sculpin are endemic to Bear Lake,
which means that they are only found within this lake itself.
They are also a species of concern within the state
because of that.
And they are an important forage fish
for many of the sport fishes of Bear Lake,
such as the non-native lake trout as well as
the native Bear Lake Bonneville cutthroat trout.
When lake levels are high within Bear Lake,
the Bear Lake sculpin are able to spawn on cobble habitat
on the Eastern shore.
This fluctuates over time, but when the lake levels are high,
they're able to use the maximum amount so
that their nests aren't too densely
populated over that Eastern shore
and that they have enough oxygen to hatch properly.
When lake levels are low, much of the cobble habitat
that the Bear Lake sculpin needs to spawn becomes exposed.
During this time, they may not have as many spots
to place their nests.
And it is also possible that if they
are able to spawn, that the eggs are not viable to hatch,
because they don't have enough resources to hide
from predators afterwards.
In order to sample the Bear Lake sculpin,
we go out on a large research vessel
and use a trawl net, which is a net that gets
pulled behind the boat on the bottom of the lake itself.
It is weighted on one side and float top on the other.
We drag the net behind the boat.
And as it is moving behind the boat,
it captures the Bear Lake sculpin
who are not large enough or fast enough
to actually escape the net itself.
After collecting the fish in the net,
we bring them up onto the deck.
We then take length measurements,
and we sample them and anesthetize them
in order to take measurements back
at the lab as well as diets.
We trawl at night because the fish are
generally more active at night.
We have gone out during the day and haven't
been as successful as at night.
And it's also very nice and relaxing to be out on the lake
during the nighttime as opposed to during the day.
Because we are working so closely with the Utah Division
of Wildlife Resources, I have a 40-year historical data set
which I've been using to couple with the lake elevations as
well as my habitat map.
By using that 40-year historical data set,
I can model what the fish were exposed to historically
and what responses we saw in the Bear Lake sculpin population,
and then, additionally, collect data myself
in order to augment the UDWR's historical data set.
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