Overview
Tracing its origins back at least 150 million years, the lake sturgeon is one of the largest freshwater fish in North America. The largest and oldest lake sturgeon grow to about 7 feet in length, weigh 200-300 pounds, and live to 150 years of age. Typically, adult lake sturgeon are about 4-6 feet long, weigh 30-80 pounds, and live to be 50-100 years old. The lake sturgeon is a prehistoric species with a shark-like tail and bony plate-armored covering. Lake sturgeon are widely distributed across the eastern and central United States and Canada. Contrary to its name, lake sturgeon can thrive in both lakes and rivers. Similar to salmon, lake sturgeon will often migrate back to the same river area where they were born in order to spawn. Lake sturgeon don’t reproduce until they are10 to 30 years old and spawn intermittently.
During the late 1800s and early 1900s, commercial harvest severely reduced the abundance of lake sturgeon while the construction of dams reduced the amount and accessibility of spawning and nursery habitat. By the late 1900s, lake sturgeon harvest was, and remains, heavily regulated and monitored, effectively removing the threat of overharvest. While the threat dams pose to the species remains across the range, reducing access to spawning and nursery habitat, there have been significant efforts to restore lake sturgeon including dam removals, fish passages, regulated release of water from dams, habitat restoration, and stocking programs. Stocking efforts have returned lake sturgeon to areas where they were formerly extirpated, such as the Genesee River (New York), St. Louis River (Minnesota and Wisconsin), Red River of the North (Minnesota and North Dakota), Tennessee and Cumberland Rivers (Alabama, Kentucky, Mississippi, North Carolina, Tennessee), Middle Mississippi River (Missouri), and Coosa River (Alabama and Georgia), as well as bolstering many existing populations across the range of the species.
Scientific Name
Identification Numbers
Characteristics
Habitat
Lake sturgeon are benthic fish that occupy the bottom habitats of large freshwater lake and river ecosystems. As their name implies, lake sturgeon spend the majority of their lives in lake and coastal systems, but when they are ready to reproduce, they migrate into large rivers to lay their eggs in rocky, swift flowing parts of the river. The larval sturgeon that hatch stay in the river for a year before migrating out to lakes where they will remain until they reach maturity and migrate back to the rivers they were born for reproduction.
In rivers, spawning lake sturgeon often lay their eggs on habitat characterized by rocky substrates, like gravel, cobble and boulders with interstitial spaces (the area between rocks) to protect the eggs, water velocity between 0.5 – 1 meters per second, water depths ranging from 0.3 – 8 m, and water temperatures between 11-15 degrees Celsius (Harkness and Dymond 1961, Threader et al. 1998, Bruch and Binkowski 2002, LaHaye et al. 2003, Peterson et al. 2007, Chiotti et al. 2008). After the eggs incubate and the larval sturgeon hatch, they drift down river and settle into nursery habitat with different habitat characteristics than the spawning habitat.
Larval lake sturgeon are often found in riverine habitats with fine sediments like sand, silt and small gravel, slightly slower water velocities between 0.1 – 0.7 m/s, and water depths typically between 0.2 and 6 m (Kempinger 1996, Threader et al. 1998, Auer and Baker 2002, Holtgren and Auer, 2004, Benson et al. 2005, Dittman and Zollweg 2006, Friday 2006).
Food
Lake sturgeon have four sensory whiskers, called barbels, in front of their mouth that help them locate food. They don't have teeth but instead, use their large, protrusible (extendable) mouth to suck up food from the bottoms of lakes and rivers. As omnivores, lake sturgeon have a broad diet which typically consists of macroinvertebrates like snails, crayfish, mussels and aquatic insects but may also include small fish and eggs.
Geography
Lake sturgeon are found throughout the St. Lawrence, Hudson Bay, Great Lakes, Mississippi River, and Coosa River watersheds - a broad distribution range encompassing five Canadian provinces and 24 states (Baril et al. 2018). In Canada, the species is found within the Hudson Bay and Great Lakes watersheds in rivers and lakes in Alberta, Saskatchewan, Manitoba, Ontario, and Quebec. In the United States, lake sturgeon occur in the Great Lakes and their tributaries, the Mississippi River Basin, as well as an isolated population in the Mobile River Basin in Alabama and Georgia. These watersheds in rivers and lakes cross 24 states: Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New York, North Carolina, North Dakota, Ohio, Pennsylvania, South Dakota, Tennessee, Vermont, Virginia, West Virginia, and Wisconsin.
Timeline
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