Helping replenish “living dinosaurs” in the Wisconsin River
Since 1997, we have been part of an effort to increase the survival rate of lake sturgeon
in the Wisconsin River.
Lake sturgeon is an ancient, mammoth fish species sometimes referred to as “living fossils” or the “living dinosaurs” of the fish world. They typically grow to be three to five feet in length and can reach up to 80 pounds.
The fish spawn every four to six years throughout their 50- to 100-year lifespan. Due to their slow reproductive cycle, lake sturgeon are vulnerable to overfishing, pollution and habitat degradation.
As a result, their numbers have been greatly reduced over the past century. The lake sturgeon has been designated as a “species of concern” in Wisconsin.
Every year in April or May, when the river’s water temperature reaches the ideal spawning temperature, our employees at the Kilbourn Dam near Wisconsin Dells, Wis. help position 900-gallon water tanks on the dam platform.
Wisconsin Department of Natural Resources (WDNR) personnel place up to three dozen sturgeon in the tanks, where they remain for three days. Eggs are taken from the females and sperm from the males. Both are combined in the same tank for fertilization.
Once the 100,000 to 300,000 eggs are fertilized, the sturgeon are placed back in the Wisconsin River. Some are tagged to track their future movement and progress.
The WDNR takes the eggs to the State Fish Hatchery in Wild Rose, Wis. The eggs hatch in around eight days. In September, the young sturgeon are released into the Wisconsin River with the hope that they will reproduce in about 25 years.Watch a WDNR video
on the egg collection process.