By Julie Geiser
With spring comes the spawning season for many species of fish in Nebraska – it is also a busy time for the hatcheries in our state that hatch fish eggs and transplant them in our waterways.
I have always been curious about how the biologists catch the fish and collect the milt and eggs and how the entire process works from start to finish.
During the Northern pike spawn on Pelican Lake at the Valentine refuge, I got to find out first-hand how everything works – from the netting of the fish to the fertilizing of the eggs and the hatching of the eggs in their glass jar homes.
Although it was an early and cold morning, I was having a blast – heck I would be out in this kind of weather hunting or taking photos anyway.
Andy Glidden, Bryan Sweet and Dana Krueger and I got in the boat and headed out to check the trap nets that were set the night before. The trap nets were placed in the shallow areas of the lake to catch the pike that were headed to shallow water to begin spawning.
The ride across the lake required breaking through some of the remaining ice on the edges of Pelican Lake – by the time we hit the first net we were all slightly frosty.
It was at that moment that I was glad I had several layers of clothes and a float coat that Bryan loaned me. The float coat is essential for these guys – if you would happen to go overboard you float when wearing this coat and boy is it warm, it blocks out the wind and water when you are riding in a boat across a frigid lake.
To me this was a day of learning – I had no idea what these guys do to get the fish they need for spawning.
The fish caught in the trap nets are put in a tank in the boat – several different species of fish are in the nets. We had Northern Pike, largemouth bass and blue gill – some of these fish were huge.
After we filled the tank in the boat full of fish, we headed to shore to unload the pike into the hatchery truck- the other species of fish were released back into the lake.
While we checked the nets at Pelican Lake, another group of fishery guys were on Merritt Reservoir checking their nets.
About 1100 males and 500 female pike were in the 15 nets set out between Merritt and Pelican Lakes. I had never seen so many fish – Some of these females were monsters! I just hope I can catch one later this spring.
After we checked all our nets we headed to the Valentine hatchery where the males and females were separated and prepared for collecting milt and eggs.
The fish are given a mild anesthetic so that they are easy to handle and don’t harm themselves or those handling them – the anesthetic takes effect in about 4 to 6-minutes.
The eggs and milt are stripped from the fish by stroking the fish from under the pectoral fins towards the vent of the fish where the milt and eggs freely flow out.
The males are first; an aspirator is used to collect the milt from the males. The milt is combined with an extender or salt solution that extends the life of the milt when kept cool. When kept at 36% to 40% the milt will last about 10 days.
Eggs are carefully stripped from the females and are fertilized with the milt taken from the males.
The eggs are carefully measured so the eggs are all fertilized – approximately 65,000 eggs per 3 milliliters of milt is used.
The egg/milt mixture is stirred with soft turkey feathers, so the eggs don’t get damaged during the fertilization process. So why a turkey feather you might ask – I asked too. Many different stir sticks have been used; paint brushes, goose feathers, and others, but the turkey feather for whatever reason works the best. The eggs don’t stick to the turkey feather, and it doesn’t damage the fragile eggs in the fertilization process.
The fertilized Northern Pike eggs were then put into jars that are circulated by water – the circulating water keeps the eggs from sticking together. The eggs remain in the jars until they are ready to hatch.
The eggs were transported to the North Platte Hatchery where the will live in their jar homes until they hatch.
The pike will be stocked at 8 Nebraska lakes including a few close to North Platte; Hershey, Hayes Center, and Cottonmill Lake in Kearney.
This is one of the really cool things that happen at our Nebraska fish hatcheries – I for one have learned a lot just by hanging around the hatchery; the terminology, techniques and about the fish species that are hatched.
My hat goes off to all the fishery folks. They do a tremendous job and in all types of weather conditions.
Pike are not the only fish that are being stripped and fertilized; the North Platte Hatchery (which is in my neck of the woods) also collected sauger and walleye.
Up to now, the North Platte Hatchery has released 2.7 million fry walleye to Swanson Reservoir, 1.7 million fry to Enders Reservoir, and 1.3 million fry to Elwood Reservoir.
More walleye will be stocked at Elwood and Lake McConaughy as fingerlings this June.