Background on Lake Sturgeon
Lake sturgeon, or Acipenser fulvescens, are a unique fish species in Michigan. These fish primarily inhabit large river and lake systems in the Mississippi River, Hudson Bay and Great Lakes basins. They are an important biological component of the Great Lakes fish community. Lake sturgeon are listed as a threatened species in Michigan and either threatened or endangered by 19 of the 20 states within its original range in the U.S.
Lake sturgeon are the only sturgeon species common to the Great Lakes basin and are the largest freshwater fish indigenous (native) to that system. Lake sturgeon can be considered a nearshore, warmwater species preferring water temperatures and depths of the mid-50 to low-70 degrees Fahrenheit and 15 to 30 feet, respectively. (It should be noted that sturgeon in Lake Michigan often prefer depths between 60 and 90 feet.) Lake sturgeon are benthivores, which means they feed on small invertebrates such as insect larvae, crayfish, snails, clams and leeches they find along the bottom of lakes and rivers.
Habitat selection by lake sturgeon varies widely throughout their range and environment they inhabit. Some adult lake sturgeon have been found to remain in a small territory during the summer months, while others have been observed long distances from their original capture site one year later. Adult sturgeon are known to intermix in the Great Lakes during non-spawning periods, but habitually return to spawn in the streams where they were born, often migrating long distances up rivers in the spring. After hatching, some young lake sturgeon have been observed to remain in their natal rivers for the first summer of their lives.
Life History Characteristics of Lake Sturgeon:
- Lake sturgeon can grow to weights of up to 200 pounds and lengths of seven feet, with females being longer and heavier than males.
- Sexual maturity in females is reached between 21 and 33 years, most often from 24 to 25 years.
- Sexual maturity in males is reached between eight to 12 years, but may take up to 22 years.
- Sturgeon spawning occurs on clean gravel shoals and stream rapids from April until June in preferred water temperatures of 55 to 64 degrees Fahrenheit.
- Female lake sturgeon can deposit 4,000 to 7,000 eggs per pound of fish.
- Sturgeon growth rates are quite variable throughout its range and depend on temperature, food availability and water quality.
- The typical lifespan of lake sturgeon is 55 years for males and 70 to 100 years for females.
This information comes courtesy of the DNR, U.S. Fish & Wildlife Service, Michigan Sea Grant and Sturgeon For Tomorrow.