Okay, whenever you're ready.
Whoops.
Sorry.
I'm gonna wreck your stuff.
Watch your head and your feet.
Well I'm looking through this little
tiny square, right?
There we go.
So often we'll get schools
of them kind of at the
pond apron here, so I
was hoping that would be the case so
you could get some footage, but
because it's sunny out they might be
further out towards the edges.
What do we have here?
So these are walleye
ponds. This is kind of a traditional
way of raising walleye for stocking
purposes, certainly in
Wisconsin and the rest of the
Midwest.
So the vast majority walleye raised
in aquaculture are done in ponds
just like this.
Raising walleye in ponds like this
is kind of challenging because
you're subject to the weather
conditions and a lot of
predators outdoors that you can't
really control for.
So we kind of stock our fish in
there shortly after hatch and
more or less hope for the best
well-following best practices.
We fertilize our ponds so that
we get a good algae growth and
zooplankton hatch for those fish
to consume.
Then eventually we'll be trucking in
minnows to feed them as they get
to the size where they can start
consuming larger fish.
And then by October they should be
roughly nine inches and
ready to stock out into the lakes.
So when did they start feeding on
other fish?
Very shortly, so as
soon as they can fit another fish in
their mouth ultimately is when
they'll start feeding on other fish.
We order different sizes
of minnows so we start with what's
called the tuffy size fathead minnow
and then they'll
be on that for a couple of weeks and
then they can get full-sized fathead
Minnows and we're ultimately
feeding them fathead and it was all
the way up until October when
they're ready to be stocked out.
For how many...
We started with 50,000
fish in each of these ponds.
So these are the fish, when we were
up here, we saw...
Some of the fish saw
some eggs come out.
Yep.
So those hatched and then they
split.
Yeah so these the
same fish that are inside are
the brothers and sisters of the fish
out here so they all hatch from the
same group and we just split
them out into these different ponds
and into the systems inside so
we'll have what are ultimately the
samefish that we're stocking both
from outdoor ponds, and
our indoor systems, and we'll see
which ones ultimately do the best
once they're stocked out in the lake
and which ones we get the better
return from. This is
definitely more expensive.
At the moment, yes, because minnow
costs have gotten really expensive,
this way of raising them is
now quite a bit more expensive than
raising them indoors, but
that can change as
minnow cost change.
The other thing is you don't know
the survival that you're going to
get out of these fish outdoors
because they're exposed to predation
and weather conditions.
So we have a bit of control over
that inside.
And we can ensure that we're gonna
have a better survival,
which makes that a little bit of a
cheaper option.
Would these fish be tougher though?
That's what we're gonna hopefully
figure out.
They might be better at catching
prey.
They might better suited to lake
conditions because they've been
raised in a pond.
It's hard to say.
So the sampling that we do in
the next couple of years will really
tell us the story on if
our indoor fish perform just as well
as these pond fish.
And we'll hopefully see it this
fall, but how do you tell the
difference?
Yeah, so we're going to
be clipping different fins for
our indoor fish and our outdoor
fish.
That way, when we do our surveys
and we pull those fish out, we can
tell if it came from indoors,
from outdoors, or if it's a wild
fish that hasn't been clipped.
So we'll look at the relative
returns of those different fin clips
in our population when we're
sampling.
And that'll be through bike nets,
sletcher shocking.
Yeah, there's going to be a variety
of sampling.
Electroshocking, we have creel
surveys where anglers will tell us
which fins they catch if they're
aware of it, and also
our population assessments that
GLIFWC is going to run next
year.
Do you ever have any idea how you
say you sometimes you can see them,
but
Yeah, sometimes you'll be able to
see them, but you really don't have
any idea what your survival
is at any given time.
What we do do, though, is we
monitor water quality really
closely. We're looking at dissolved
oxygen constantly.
We're look at the phytoplankton
population.
We're are looking at the relative
phosphorus and nitrogen
concentrations, and we're
trying to keep them in the most
optimal parameters for these
fish to do well.
And if we do all of that right and
we get lucky with the weather and
get lucky with predators then we'll
get a good amount of fish out of
here. If any of those things go
wrong it can change that
equation quite a bit and we might
not get very many fish out and that
happens sometimes.
So it's just a bit more of a gamble
with these outdoor systems.
It keeps it fun of course,
but it's a bit more challenging for
sure.
What are the most common predators
out here?
Yeah, there's you have a fence you
have some
Yep so you'll notice we have our
fence and we have that flashing that
goes all the way around and that
hopefully prevents any frogs
and turtles and
you know anything else from getting
in.
In practice stuff still gets in
certainly.
So those can be predators.
Birds are far and away the biggest
predators that we have to worry
about.
We'll get mergansers flying in here,
we get kingfisher every now and
then.
There'll be herons that like to
hang out in the shallows can
probably do. A big number on
the population in these ponds,
so part of it is
trying to be out here enough to try
to scare those birds away as well,
but you can't be here all the time
so they're going to find a way.
We'll actually occasionally get
otter, raccoons,
all kinds of fun stuff that can
come in here and take out your fish.
How many ponds do you have here?
So we have four ponds here
and we're currently running three of
them.
In theory, how many fry were put
up?
We started with 50,000
fly right after hatch in
each of these ponds.
So it's really interesting though,
even though these- 150,000.
150,00 in total, yep.
And roughly 80,000 inside.
So a little bit of a different
number.
But it'll be interesting, even
though all these pond are right next
to each other and we're doing more
or less the same thing to each of
this, without fail we'll
get quite a bit of different
survival among these pons.
So that's why.
It's good to have replication when
we're doing studies, right?
So, but yeah, 150 fish in
total in these ponds, at least at
the start, roughly 80,000
total indoors, and
hopefully we'll get the numbers that
the Lake Association and Red Cliff
are looking for for stocking and
enough numbers to get those returns
for our study.
So Red Cliff has ponds as well,
right?
Yep, Red Cliff has three ponds.
They look a little bit different
because they're lined with
a HDPE liner.
And that's one of the studies that
I'm hoping to get funding
to look at is, in the
state of Wisconsin, the
Wisconsin DNR has noticed that a lot
of the walleye raised in ponds
will have really skewed sex
ratios towards female
sex ratios in those ponds, and
we're not really sure why.
It could be due to temperature
differences.
Those lined ponds are darker, so the
water temperatures might be warmer
at critical periods.
But it also could be, due
to something leaching from those
HDPE pond liners, that could
have endocrine disrupting potential.
So I've put in a grant to look at
that, take water samples,
and look at if there's any endocrin
disruptors that are at biologically
relevant concentrations that could
be causing those skewed sex ratios.
Essentially killing the males,
not changing the males into females.
No, certainly not killing the
males, but leaching
compounds that mimic
estrogen and can bind to
the estrogen receptor and
can therefore cause
maturation and development to go
a little bit differently for the
males.
Increased the telogenin expression,
which is an egg yolk protein that
males aren't supposed to express.
And you'll see males,
otherwise male fish,
producing ovaries and
having testes that have ovary,
ovarian cysts inside of them and
stuff. So it's really interesting
when that happens.
So we'll be able to look at these
fish and kind of see if that is
happening with those plastic lined
ponds.
Because interestingly we don't see
the same skewed sex ratios in our
clay lined ponds that don't have a
plastic liner.
So, are they technically
hermaphroditic then, or what is the,
how do we describe that?
Yeah, so fish are really
interesting in sex determination and
maturation.
So we're still figuring out a lot
about the processes involved
in sex determination for
walleye. It's looking like they're
not XY sex
determining, but a lot more
research has to be done to figure
out the exact mechanism for sex
determination.
There's a lot of organisms that have
temperature-dependent
maturation and sex determination.
And it's possible that walleye fall
into that category.
So that's why we're also looking at
the temperature aspect with those
lying ponds that might be a little
bit warmer.
That could be the mechanism and not
endocrine disruptors for those
skewed sex ratios.
So you can, can you sex the fish
when you're stocking them when
they're that size?
It's difficult, it's probably about
as early as you can sexless fish,
but we'll take some samples
and look at the histology
and be able to tell if they have
testes or ovaries at that
point.
So in the lab, you can do that right
now? Yep.
You wouldn't be able to take one and
visually look at it.
Spring when you're harvesting eggs
you have to express them to try and
figure out male and female.
Yeah, yep.
And when they're nine inches, it's
almost impossible.
There is a
sexual dimorphism where
males will be quite a bit smaller
than females on average, but that's
not a reliable enough metric that
you can take a cohort and
just measure them and say this
smaller population is likely all
male, so.
Otherwise
How does it look?
So our ponds, we had
a really overcast week last
week. And that can be a
challenge, because even if we have
optimal nitrogen and phosphorus
ratios in the
ponds if we don't have sun,
we're not getting that algal bloom
that we want.
And we don't have as good of a
zooplankton bloom.
So these are much clearer than we
would like. We want them to be more
turbid. The walleye like that and
the things with a lot of meat like
that.
So they're clearer than we would
like. You don't want to be able to
see the bottom generally.
But we have a nice sunny day so
hopefully that'll kick things off
and we'll see some some algal
blooms and really good zooplankton
hatch.
All the stuff over here, that's
good. That's what we need.
Yeah, yeah, ultimately.
Granted, we want the smaller
algae, like the small little
green algae, so
not the large kind of filamentous
algae on the top.
I think we're just going to get some
b-roll out here and then we'll
join you back in.
Plastic, man.
Makes you want another punch of your
being a touch of plastic again.
Does their thing not working affect
our schedule at all?
Oh, no.
As long as they start today in time,
they'll see some video recording.
Sure. We don't even desperately need
them.
Yeah, just drop one down the grave,
but it'll be there
tomorrow.