Minnesota DNR Fisheries Management — Egg Take

>>Carl Mills: The Pine River Walleye trap
has been in existence since 1922. [music ] It is just as busy today as it was back then. The trap is usually put in the first week
of April each year, but this varies depending on when the ice goes out. As water temperatures
reach 40 degrees, walleye swim up Pine River to spawn on the rocks. Our trap intercepts
them on their way up stream. It usually takes three days to complete the
trap. The trap is completely removed once we are
finished. The trap is located just upstream of where
the Pine River flows into upper White Fish Lake.
Here is a look downstream at White Fish Lake. You can see that it is still covered with
ice. It usually remains on the lake throughout the whole operation. Ducks and other waterfowl
stop to rest on their journey back to their summer homes.
The first thing we do each day is go through the fish we have been holding from previous
days. The male walleyes are in one holding pen or crib. Females are in another.
The females are checked to see if they are ready to release eggs, we call this ripe.
Females that aren’t ripe are called green. The process of removing eggs from fish is
called stripping.>>Lloyd Anderson: What we’ve got in here
are the females that haven’t been ripe yet and we go through the crib every day. If the
female is ripe we’re going to strip her, if she’s not then we’re going to put her
in the crib and see if she’s ready tomorrow. Sometimes when they come up it takes them
a couple of days to ripen up. It depends a lot on the water temperature; the warmer the
water, the quicker they ripen up. So we’re holding about 150 females in here
right now and we’re going to find out how many of them are ripe and ready to give their
eggs. Checking the females here to see if they’re
ripe; these fish have been in here since yesterday. We give a small squeeze on the stomach and
you can see if you look here, the eggs are starting to come out. So she’s ready to
go. We’re going to take her over to the table.
>>Carl: Ripe females are placed in this tank for stripping.
The males are placed in this tank. Females are taken from the tank and the eggs
are squeezed into a bowl. Each female will have one to two quarts of
eggs. Each quart contains about 120,000 eggs. We usually put the eggs from two females in
each bowl. Then the sperm from four to six males is added.
The eggs are stirred constantly to ensure sperm reaches each egg.
Once we are done with the fish, they are released.>>Lloyd: Now one of the things when the eggs
come out of the female they’re made to stick to the rocks, so they’re real sticky. If
you let them just sit in the bowl like that they are all going to get into a big ball
and when they get into a big ball the ones in the center are going to die. So what we
do to keep them from sticking so much is we add well-drillers clay, and this actually
takes the stickiness off of them Each individual egg has got to be able to float around and
have water going around them because the eggs are just like fish, they get their oxygen
out of the water.>>Carl: The bowls of fertilized eggs are taken
back to shore where they are washed and added to the tub.
Now that the clay has removed the stickiness, it is washed off so the eggs can breathe.
The next step is to empty the trap. These two wings that extend from shore to shore
funnel fish that are swimming upstream into our trap. The trap has been set all night
long. We will herd the fish to the end with this
tamarack pole. Fish are netted out and separated by sex. The largest fish we see are around 12 pounds. Any other fish species, such as white suckers,
northern pike, redhorse, or whitefish are released to continue their journey upstream.
We will typically handle around 3,000 walleyes per year.
Any ripe females are placed in the tank to be stripped. After we are done with the trap, we allow
the eggs to harden for a couple hours so they don’t break during transportation. Once hardened, they are transferred into milk
cans and taken to the hatchery. These are the same milk cans that were used back in
the 1920s. The number of eggs we take varies from year
to year, but we usually reach our quota within two weeks.

local_offerevent_note September 26, 2019

account_box Gilbert Heid


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