Precision Required For Walleye Spawning Collection
A fishing enthusiast, CBS4’s Paul Day tagged along in early April with the volunteers and wildlife employees who are behind Colorado’s annual walleye spawning effort. Watch his report in the video clip below.
DENVER (CBS4) – Clark Baker is down on his knees scooping and sorting fish of all sizes.
“I been doing this for 40 years so I make it look easier than it actually is,” he says.
Nearby, Ed Schlottach is using a goose feather to stir a bowl full of newly fertilized fish eggs.
“OK, it takes me 90 seconds to do this because that’s all the sperm stays active and alive,” he explains.
Schlottach and Baker are part of dedicated band of volunteers who help maintain Colorado’s walleye fishery.
“It’s very successful,” says Jeff Spohn, an aquatic biologist with the Colorado Division of Wildlife.
Using a floating barge, boats and nets supplied by CDOW, volunteers collect eggs and semen from spawning walleye.
Walleye do spawn naturally on their own, but it’s not nearly enough. To fully support the state’s fishery, 100 million eggs must be gathered. So this spawn collection effort has become an annual spring tradition at reservoirs like Chatfield.
“We set a whole string of nets along this dam,” explains Spohn.
They’re gill nets but the walleye rarely die because water temperatures in the mid-forties keep the fish from struggling much once they’re snagged.
Riding out to check the nets, volunteers carefully unsnag the fish and put them in holding tanks. The tanks are brought to the barge where walleye are sorted by sex.
Spohn says a pregnant, three pound female is capable of yielding 60,000 eggs. But she has to be “ripe” and the job of checking falls to Baker.
“You can just kind of tell (by looking) that they’re ready,” he says.
Removing the eggs is done by gently stroking the bloated belly in the direction of a vent, located just in front of the tail.
The males are gently squeezed to capture semen. Once combined another ingredient is stirred in: bentonite.
The liquefied clay is an anti-adhesive. It’s necessary because walleye eggs are naturally sticky, but in a hatchery that can be devastating.
“You don’t want them sticking together, that can lead to fungus and wipe out everything,” explains Kurt Davies, another aquatic biologist with CDOW.
It’s why Schlottach is on the business end of a goose feather, stirring the bentonite, semen and eggs.
“We separate them so they don’t clog up and they don’t suffocate,” he adds.
Besides Chatfield, walleye eggs are also collected at Cherry Creek and Pueblo reservoirs. The entire batch is delivered to state hatcheries where — in just a couple weeks — baby walleye are born.
The hatch rate is a remarkable 80 percent.
Small fish are quickly returned to the reservoirs and released from plastic bags.
“About a quarter inch in size,” explains Spohn.
The lucky ones grow to adult size and the spawning process is repeated all over again.
Walleyes provide good sport and delicious table fare for anglers like Schlottach and Baker.
But on collection day, don’t expect to see a fish fry.
After getting a fin clipped, all the walleye worked are released alive.