Fish Hatchery Program

"Giving nature a hand"

Each spring, with special permits from the Ministry of Natural Resources, volunteers catch walleye in order to collect and fertilize eggs. The fertilized eggs will be placed in special incubation jars in the Fish Hatchery building. Some will be released back into the lakes as fry. Others will be reared to the fingerling stage over the summer in our dedicated rearing ponds. The fingerlings will then be released later in the summer, back into the watershed from which the eggs were collected. Each year volunteers collect up to 500,000 eggs from Lake Temagami and up to 1,000,000 from Cassells and Adjoining Lakes. This is a lot of work and we currently have about 40 volunteers who participate at various stages of the process. The pictures below show some of the highlights in the Fish Hatchery Program.

Volunteers use special nets to catch fish for egg collection.

Egg collection generally starts in late April or early May when the water temperature reaches 5 degrees Celsius.

Female walleye in a holding container.

Female fish are carefully "milked" of eggs (roe), and sperm (milt) is collected from males for fertilization. The fish are then released back into the lake.

closeup of hands holding fish and feather

The Fertilization Process

At the collection site, the roe and milt from the walleye are very carefully mixed in a bowl using a feather. Then the fertilized eggs are transported to the hatchery building. During the process, great care is taken to prevent harm to the fish or the eggs.

Incubating the Eggs

The fertilized eggs are transferred to special “bell jar” incubation jars in the hatchery building. Hatch rates in these incubators are much higher than hatch rates in the wild.

Starting to Hatch

After 14-21 days, eggs “eye-up” and begin to hatch and after a few more days they begin swimming. Then the water that is constantly circulated through the system transfers them into holding tanks in the hatchery room.

Newly Hatched Fry in the Holding Tanks

After hatching, about 80% of the walleye fry are transported to area lakes and released. This must be done within a few days of hatching, so it is a very busy time for our volunteers.

Walleye Rearing Ponds

About 20% of the fry are moved to rearing ponds where they grow to “fingerling” size (2 to 3 inches in length). Volunteers feed the ponds with a mash that promotes zooplankton for the young fish to live on. Separate ponds are maintained for each watershed.

Draining the Rearing Ponds

After the walleye reach the desired length, they are then removed from the ponds and stocked in area lakes. At the end of each hatchery season, the ponds are drained to allow for removal of any remaining fingerlings.

Any lakes stocked by the hatchery must be pre-approved by the MNRF and a minimum of 10% of the fry/fingerlings must be distributed to the donor site.

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