Fight for Survival

By Craig Gemming | November 2, 2004
From Missouri Conservationist: Nov 2004
THIS CONTENT IS ARCHIVED
Body

Imagine yourself fishing for catfish on the Missouri or Mississippi river. Feeling a sharp tug on the end of your line, you set the hook and start battling what you think is a big catfish.

After several minutes, you pull a fish up from the murky depths and discover it looks like a creature from a Hollywood monster movie. It has a shark-like body, a long, bony snout and is armored with rows of sharp, bony plates. You've caught a sturgeon.

Sturgeon are an ancient family of fish. They evolved during the time of the dinosaurs. Missouri has three species of sturgeon: pallid sturgeon, lake sturgeon and shovelnose sturgeon. Pallid sturgeon and lake sturgeon are endangered species. Shovelnose sturgeon, the most common of the three, has recently become a species of concern. Habitat loss and past, unregulated commercial fishing are the primary reasons for their decline.

About Sturgeon

Sturgeon are found in the Missouri and Mississippi rivers. These bottom-dwelling fish prefer strong current and live in areas having a hard bottom. At certain times of the year, they can be found along sand and gravel bars or in deep, scoured areas of the river. Sturgeon have long, flat snouts, large pectoral fins and long, streamlined bodies that help them move about and hold position in strong current.

A sturgeon's diet consists mostly of larval aquatic insects, crayfish, snails, small clams and small fish. As lake and pallid sturgeon grow, they depend more on small fish for food. However, sturgeon sometimes scavenge dead animal matter and are often caught by catfish anglers using worms or cut bait (pieces of fish).

Lake sturgeon can live up to 150 years, grow up to 8 feet long and weigh up to 300 pounds.

Pallid sturgeon can live more than 40 years, reach 6 feet long and weigh up to 65 pounds.

Shovelnose sturgeon, the smallest of the three species, can live more than 20 years but rarely measure more than 30 inches long or weigh more than 5 pounds.

Like most other long-lived species, sturgeon take a long time to mature sexually. It takes 15-20 years (25-40 lbs.) before a lake sturgeon can spawn for the first time; 7-12 years (6-12 lbs.) for a pallid sturgeon; and 5-7 years (2-3 lbs.) for shovelnose sturgeon. Also, unlike most other fish species, sturgeon don't spawn every year. A female lake or pallid sturgeon only spawns once every 3-5 years, and a female shovelnose sturgeon spawns once every 2-3 years. Their slow rate of maturation and infrequent spawning make sturgeon extremely susceptible to overharvest.

Sturgeon Identification

All three species of sturgeon found in Missouri look somewhat alike. It's especially difficult to tell the difference between pallid sturgeon and shovelnose sturgeon. Lake sturgeon and pallid sturgeon are endangered and protected by law. These two species must be returned to the water unharmed immediately after being caught. Therefore, it is very important for anglers to learn how to quickly identify each species.

Lake sturgeon, often called rubbernose sturgeon, have a shorter, rounder snout than the other sturgeon, which have shovelshaped snouts. Lake sturgeon also have smooth barbels; pallid and shovelnose sturgeon have fringed or serrated barbels. These barbels, located at the front of the mouth, help the fish locate food and find their way along the bottom of the river. Young lake sturgeon are mottled light-brown, but adults are solid dark brown or slate colored.

Shovelnose or Pallid?

Biologists use four main characteristics to tell pallid sturgeon and shovelnose sturgeon apart.

  1. The shovelnose sturgeon has a shorter snout and head than the pallid sturgeon.
  2. Shovelnose barbels form a straight line across their bases. Pallid sturgeon barbels form a crescent-shaped line at their bases.
  3. Shovelnose barbels are attached equally distant between the mouth and tip of the snout. Pallid sturgeon barbels are attached closer to the mouth than to the tip of the snout.
  4. The belly of a shovelnose sturgeon is covered with thin, scale-like plates. Pallid sturgeon have skin-like, scaleless bellies.

In addition, the two inner barbels on a shovelnose sturgeon are about as thick and nearly as long as the two outer barbels. Those barbels on a pallid sturgeon are usually thinner and much shorter than the outer barbels.

Also, adult shovelnose have light brown to buff sides and back and a white belly. Young pallid sturgeon are about the same color, but as they mature, their sides and back turn grayish white.

Threats to Survival

Of the 24 species of sturgeon worldwide, 16 are classified as endangered. Four are classified as threatened, and four are classified as vulnerable. As mentioned, Missouri's lake and pallid sturgeon are endangered. Habitat loss and unregulated commercial fishing in the past are the primary reasons for their decline. However, other factors, including habitat alterations by humans to the Missouri and Mississippi rivers, pollution and the introduction of exotic species, have contributed to the decline of these species.

Sturgeon are excellent barometers of big river environmental conditions because of their wide distribution, migratory nature and diverse habitat requirements. For most of their existence, sturgeon thrived in the diverse habitat that was once found in the Missouri and Mississippi rivers. Historically, our big rivers were wide and shallow, consisting of braided channels, sand bars, gravel bars, sand shoals and numerous wetlands.

Shallow areas with gentle current served as nursery and seasonal habitat for most fish species, including sturgeon. However, development of the big rivers for flood control and commercial navigation has adversely altered much of the 3,350 miles of river habitat in the sturgeons' range.

In the last 65 years, 28 percent of the Missouri and Mississippi rivers have been impounded by dams, creating unsuitable, lake-like habitat. More than 50 percent of each river's length now consists of deep, uniform, fast flowing, restructured channels, and 95 percent of the wetlands have been eliminated.

Commercial fishing and overharvest also have had a big impact on sturgeon. During the late 1800s, lake sturgeon were so common that people indiscriminately killed them to prevent them from damaging fishing nets. Rendering plants processed them for fertilizer, and steamboats burned their oily flesh for fuel. People also developed a taste for their flesh and eggs. By the mid 1900s, both lake and pallid sturgeon were already considered rare. Their numbers have continued to decline.

Of our three species, the shovelnose sturgeon is the only species that can be legally harvested. It managed to escape serious exploitation until recently, when interest in shovelnose caviar increased.

From 1998 to 2001, the shovelnose sturgeon harvest on the Mississippi River by commercial fishermen increased more than tenfold. This dramatic increase concerns biologists.

The demand for shovelnose sturgeon continues to increase despite health advisories issued by the Missouri Department of Health & Senior Services that warn of high contaminant levels in the fish and their eggs.

Road to Recovery

During the early 1990s, the Conservation Department developed "action plans" to help the recovery of lake and pallid sturgeon. Goals of the plans are to reestablish self-sustaining populations so they can be delisted as endangered species and ultimately provide limited sport fisheries. These plans stress the restoration of both species through habitat improvement, artificial propagation, protection, research, management and education. The Department has been implementing all aspects of these plans over the last several years.

Restoring and improving habitat are key to the recovery of our endangered sturgeon. We continue to work with the Corps of Engineers by designing and installing projects that will increase the diversity of habitat available to all native river fish, including our endangered sturgeon.

We are also working with the Corps of Engineers and many other state and federal agencies to achieve a balanced approach to river management that will benefit all interests and still provide for more abundant fish and wildlife.

Since 1984, the Department's Blind Pony Fish Hatchery has raised and stocked more than 13,000 pallid sturgeon and 150,000 lake sturgeon into the Missouri and Mississippi rivers.

The Department also has recently started a long-range, statewide sturgeon monitoring project to track population trends of all our species. Since the mid 1990s, fisheries biologists across the state have been sampling and gathering information on sturgeon from both the Missouri and Mississippi rivers. Biologists are tagging sturgeon to collect more information on population size, growth, movement and harvest.

Properly managing our sturgeon populations is also important to their recovery. Pallid and lake sturgeon are illegal to harvest and have been protected by law for many years. We have also intensified our efforts to better regulate harvest of shovelnose sturgeon. Commercial harvest regulations for shovelnose sturgeon have become more restrictive over the past few years. Even so, population trends have continued to decline. As a result, the Conservation Department may consider even more restrictive regulations in the future.

Sturgeon Survival

Rebuilding sturgeon populations will require a concentrated effort to solve many problems affecting these big river fish. Restoring habitat and balancing the management of our big rivers is an important first step. If all big river stakeholders work together to find and implement solutions for the sturgeons' recovery, then Missouri's aquatic dinosaurs will win their fight for survival.

LAKE STURGEON

Lake sturgeon have the shortest, roundest snout of the three species. The barbels near their mouth are smooth, rather than fringed or serrated.

PALLID STURGEON

The belly of a pallid sturgeon is smooth and scaleless. Theirs is the longest snout of the three species, and a line across the barbels would be curved.

SHOVELNOSE STURGEON

The bases of a shovelnose's barbels are in a straight line. The belly of a shovelnose sturgeon is covered with thin, scale-like plates.

REPORTING YOUR CATCH

Anglers catching a tagged lake, pallid or shovelnose sturgeon are encouraged to report the following information:

  1. Species caught
  2. Date caught
  3. Where caught (river mile/nearest town)
  4. Tag number, length, and weight.

This information will help us achieve our goal of restoring our sturgeon populations.

To report a tagged sturgeon, call toll free 866/762-3338. For more information about sturgeon identification, contact the Missouri Department of Conservation, Resource Science Center, 1110 S. College Ave., Columbia, MO, 65201, (573) 882-9880 or Central Region Office, 1907 Hillcrest Dr., Columbia, MO, 65201, (573) 884-6861.

This Issue's Staff

Editor - Tom Cwynar
Managing Editor - Bryan Hendricks
Art Director - Ara Clark
Artist - Dave Besenger
Artist - Mark Raithel
Photographer - Jim Rathert
Photographer - Cliff White
Staff Writer - Jim Low
Staff Writer - Joan McKee
Circulation - Laura Scheuler