Walleye Egg Take Process

Oneida Fish Hatchery - Walleye Egg-take

Each year, DEC's 12 fish hatcheries produce large numbers of a variety of fish species for stocking into waters across New York State. Raising these fish is a big task that involves many crucial steps.

The Oneida Fish Hatchery specializes in raising walleye. In the early spring, hatchery personnel begin the process by setting trap nets to collect adult walleye in Oneida Lake. Oneida Lake (on Scriba Creek) provides all of the walleye for New York's stocking program. The following is a brief overview of the process followed to produce sufficient numbers of healthy walleye for stocking.

Tending Nets

Walleye typically spawn from late March to early April, right after ice-out. Each day, approximately 9 to 12 live trap nets are set perpendicular to the shore to catch adults. The nets are checked daily and any caught fish are transported back to the hatchery in large tubs of water.

Sorting Fish

Once the fish arrive at the hatchery they are sorted according to sex into raceways. Ripe female walleye (i.e. ready to release eggs) and males are separated from non-ripe walleye.

Egg Take

Next, eggs and milt (sperm) are removed from the adult walleye at stripping stations. Each station consists of a crew of five people. Two crew members supply the mature fish to two other crew members who then squeeze the female and male walleyes, causing the eggs and milt to flow out of the fish into a single large bowl. The remaining crew member stirs the "mixture" and adds water to prevent the eggs from sticking together, which ensures fertilization. For each bowl there is a 1:2 ratio of fish used- 15 females for every 30 males.

Egg Hardening

Hatchery personnel collect four bowls of the egg/milt mixture which they add to a tub containing a tannic acid solution. The tannic acid removes the adhesiveness from the fertilized eggs. An iodine solution is added to eliminate any bacteria or viruses. The tub is stirred for three minutes, rinsed three times, refilled with water and then left to sit for an hour. During this time, the eggs absorb water and become firm (hardens).

Jar Incubation

After hardening is completed, the fertilized eggs are placed in jars that serve as incubators. Here, water is run over them at a rate of one gallon per minute. This keeps the eggs aerated. Each jar holds about three quarts of eggs, or 450,000 eggs per jar. With 720 jars filled over the 7-10 day collection period, that makes 324 million walleye eggs!

Incubation and Hatching

The eggs remain in the jars for three weeks. During this time period workers tend to the eggs, including sifting to eliminate clumping and preventing suffocation, removing any dead eggs that float to the top, and administering Formalin daily to eliminate fungus. Once the eggs hatch, the walleye fry swim to the top and then out into the hatchery raceway where they have two possible fates:

1. To be stocked as fry
2. To be grown in earthen ponds (pond-reared) at South Otselic and Chautauqua Fish Hatcheries until they reach 2 inches long and are stocked

Stocking

Each year DEC produces approximately 300,000 pond-reared and 200,000,000 walleye fry to stock into 50 or more waters across the state. Thanks to DEC's Walleye Stocking Program, quality walleye fishing can be found in most DEC Regions. For more information on top walleye waters close to you, contact your local DEC office.