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Phone: 231-584-2461 E-mail: JordanRiver@fws.gov |
Lake Trout
The Jordan River National Fish Hatchery receives shipments of lake trout eggs from the middle of November through early January. These eggs have already developed to the stage where the eye of the developing fish is visible. They come from the Saratoga NFH (Saratoga, Wyoming), Sullivan’s Creek NFH (Brimley, Michigan), and Iron River NFH (Iron River, Wisconsin).
We now raise as many as four different strains of lake trout each year: Lewis Lake, Seneca Lake, Superior-Apostle Islands and Superior-Traverse Island. A grand total of 5,225,720 eggs were received in 2005.
These eggs were spawned in the fall of 2004 and the resulting fish will be released in the spring of 2006, at which time they should be approximately six to seven inches in length.
After arriving at the hatchery, the eggs are disinfected and then placed in incubation jars in the tanks and indoor raceways. They remain in the jars until the fry hatch. By the end of February the lake trout will be feeding. This marks the beginning of the busiest time of the year for the hatchery. Two year classes of lake trout are now being intensively cultured.
Additionally, all of the one year old lake trout from the Jordan River NFH are marked during the winter prior to their release into the Great Lakes. They are either fin clipped to identify them as hatchery-produced, which entails removing one or more fins, or they are tagged with coded wire. Fish to be released in the spring of 2006 will have their left pectoral fin clipped. The coded wire tagging process involves removing the adipose fin and injecting a coded wire tag (CWT) in the snout of the fish. The marking and tagging is necessary to differentiate hatchery reared year classes stocked into the Great Lakes. The mark and tag data is used in evaluation of the Great Lakes Lake Trout Restoration Program. Survival rates, strain performance, migration and distribution patterns are some of the things measured by researchers using this data. All the clipped or tagged fish will be released offshore in Lake Michigan and Lake Huron during April, May and June.
