Along the Atlantic coast, from Canada to Florida, a prehistoric creature still exists. The Atlantic sturgeon (Acipenser oxirinchus) is a primitive fish that has been around since dinosaurs roamed the Earth, approximately 150 million years ago.
A sturgeon may live up to 60 years, weigh up to 800 pounds and reach lengths of up to 15 feet. Other identifying characteristics are a soft, toothless mouth located on the underside of a long, hard snout, and four sensory barbels projecting from the mouth. The head is covered with bony plates. Five rows of bony shields, or scutes, cover the body. The dorsal and anal fins are located far back on the body and the upper lobe of the tail is much longer than the lower.
During the late 1800s and early 1900s, Atlantic sturgeon was an important commercial fishery in the Chesapeake Bay, as well as other bays and rivers along the Atlantic Coast. Today's population has declined by more than 90 percent. Major causes of the decline include overfishing, the damming of rivers, and degradation or loss of habitat.
An anadromous fish, the Atlantic sturgeon spends most of its life in brackish or salt water, but migrates into coastal rivers to spawn. Atlantic sturgeon mature very slowly. Sexually mature males are at least 11 to 12 years old and weigh up to 100 pounds while females are 18 to 20 years old and weigh more than 100 pounds. Males migrate into fresh water during March and April, one month ahead of females. They do not school together but meander alone. Females lay 1 million to 2.5 million eggs in flowing water up to 60 feet deep. Both males and females may remain in the river until late fall before migrating back to the Atlantic. After hatching, the young may remain in their natal areas up to 5 years before beginning their journey to the ocean.
Sturgeon use their snouts and barbels to root around in bottom sediments, vacuuming up organisms with their soft mouths. Their diet consists of mollusks, worms, gastropods, isopods, shrimp and small fish, as well as large amounts of mud and debris.
Other than sharks and humans, sturgeon have few predators. Today, the majority of sturgeon are taken as incidental catch in other fisheries before they reach maturity. Biological characteristics of the Atlantic sturgeon, such as slow growth, advanced age at maturity, and long periods between spawning, make the fish particularly vulnerable to human-induced impacts and changes to its habitat.
Harvesting Atlantic sturgeon was an important industry from colonial times to the turn of the century. During the 1700s, sturgeon meat, eggs and oil were exported to Europe. The most valuable part of the fish was its eggs, or roe. Prepared as caviar, this delicacy was in high demand in Europe. The delicate meat, comparable to pork or swordfish, was smoked and eaten. Even sturgeon air bladders were valuable. They were used to make isinglass (a clear gelatin), jellies, clarifying agents for beverages, plasters, waterproofing agents, adhesives and lubricants. By 1850, sturgeon meat and roe became popular in this country as well. By the late 1800s, annual landings as high as 7 million pounds were reported.
Traditionally, Atlantic sturgeon fishermen worked the Hudson, Susquehanna, Delaware, Potomac, York, James, St. Mary's and St. John's rivers with large drifting gill nets, some 1,500 feet long and 21 feet deep with a mesh of 13 inches. By the 1920s, the annual harvests fell to as little as 22,000 pounds.
Today, sturgeon are still caught with gill nets, haul seines, pound nets, fish slides, and weirs. Fishing seasons generally occur during spring spawning migrations and some fall migrations. Fishing occurs in the Hudson River and along the Atlantic Coast with size limits and/or pound quotas. Harvests are only a fraction - less than 10 percent - of their peak a century ago.
The restoration and management of Atlantic sturgeon is under way. Because so little is understood about the migration patterns of Atlantic sturgeon, the U.S. Fish and Wildlife Service, in partnerships with several states, has initiated a program to tag wild sturgeon along the Atlantic Coast and the Gulf of Mexico. Serial numbers printed on the tags can be reported to the service when a tagged fish is caught. Participants then receive a reward. In this way, citizens help to provide data on distribution, mortality, age, growth and coastal migration patterns of the fish.
Other efforts include producing hatchery-reared fish for further study and for possible release into the wild, and raising the minimum size limit on the Atlantic sturgeon fishery. Virginia has closed its Atlantic sturgeon fishery entirely. In the Chesapeake Bay, no Atlantic sturgeon greater than 7 feet has been caught since 1970.
It will take more than the reduction of fishing pressure and the stocking of fish to bring the Atlantic sturgeon back. With increased development and deforestation, the input of forest litter (decaying organic matter found on the forest floor) into streams and rivers has been reduced. Eggs need to attach to forest litter to keep from being swept downstream.
Water quality is critical to the survival of adults and juveniles. Excessive amounts of nutrients in waterways can create sudden blooms of phytoplankton. After the phytoplankton die, decomposition uses up large amounts of oxygen. This can lead to dangerously low dissolved oxygen levels along the bottom where sturgeon feed.
Like all anadromous fish, Atlantic sturgeon must have access to their spawning grounds. By removing blockages or altering the design of dams to accommodate fish passage, sturgeon can reach the upstream areas so critical to their reproduction.
With citizens working in cooperation with local and federal agencies to lower fishing mortality, reduce pollution, provide fish passage and possibly enhance stocks through hatchery production, the Atlantic sturgeon may once again become a vital and familiar part of the Chesapeake Bay heritage.
For more information about Atlantic sturgeon and restoration activities, contact:
U.S. Fish and Wildlife Service
Maryland Fisheries Resource Office
177 Admiral Cochrane Drive
Annapolis, MD 21401