Lake Sturgeon (Acipenser fulvescens)

(c) MN DNR, C. Iverson

Fish of the Mississippi River

Introduction

Lake sturgeon are the largest fish found in Minnesota, capable of reaching 6.6 feet in length and nearly 100 pounds. Found in Minnesota waterways year-round, this long-lived, slow-growing fish travels widely in loose aggregations. It uses sensitive barbels to locate insect larvae and other invertebrates, snails, leeches, small mussels, and small fish, which are suctioned off the river bottom by an extendable mouth.

Lake sturgeon were once very common in the Upper Mississippi River. But between 1894 and 1931, the commercial catch of lake sturgeon dropped from 249,000 pounds to 0. This ancient, gentle giant was brought low by commercial overharvest for meat, caviar, and skin. Dam construction, siltation, and pollution have reduced its access to spawning gravel beds and feeding areas. Yet today’s population is rebounding, thanks to restoration and reintroduction efforts of the Minnesota Department of Natural Resources, the U.S. Fish and Wildlife Service, and other federal agencies and local and tribal governments. Its recovery has been strong enough that Minnesota sport anglers with a special tag may keep one lake sturgeon per year.

Fascinating Facts

• Only 10-20% of adults within a lake sturgeon population are sexually active and spawn during a given season, which accounts for the slow recovery rate of its population.
• The commercial harvest of lake sturgeon in Minnesota was closed in the 1930s.
• The Ojibwa people called lake sturgeon "nah ma," meaning "King of Fishes." They pursued them for meat, skin, oil and waterproofing (from a fluid in the fish's bladder).

Identification

Key ID Features: Lake sturgeon have a flattened snout with a toothless mouth on the underside of the head. The body is covered in 5 rows of large, prominent bony plates (or scutes) instead of scales.

Present in Park: Yes, but rare.

Habitat: Quiet waters of large rivers and lakes. Recent surveys in the Mississippi River below Lock and Dam No. 3 (Red Wing) found most lake sturgeon in the tailwater zone of dams.

MN Status: Species of special concern

For Further Reading

• Dickson, Tom. 2008. The Great Minnesota Fish Book. University of Minnesota Press: Minneapolis: University of Minnesota Press. 154 pp.
• Minnesota Department of Natural Resources. “Rare Species Guide - Lake Sturgeon.” Last modified 2016. http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selectedElement=AFCAA01020