Fact
Sheet: SHORTNOSE STURGEON
Scientific Name: Acipenser brevirostrum
Habitat:
Main channel of large rivers, and estuaries; may be found in all
water depths in rivers.
Weight: Adults average about 8 pounds.
Length: Adults, 36-38 inches.
Life
Expectancy: Ages from 50 to
75 years have been reported (Southern populations less than 20 years).
Food: Primarily invertebrates, insects, crustaceans, mollusks, and
snails.
Status: Federally and state endangered
Identification:
Sturgeon are primitive-looking fishes, with a heterocercal tail (the upper lobe
is much longer than the lower lobe) and a body covered with 5 rows of large bony
plates. These heavy, cylindrical fish have an elongated, bony snout, with a
tube-like mouth located on the underside of the head. The mouth protrudes
several inches when the fish is feeding. Shortnose sturgeon range in color from
grayish-olive to brownish above, shading to white on the belly.
Shortnose
sturgeon can be distinguished from Atlantic sturgeon by the relative width of
their mouths.
Shortnose
sturgeon (below) could be called "bigmouth" sturgeon; their
mouth widths (inside the lips) are greater than 60 percent of the distance
between the eyes.
Atlantic sturgeon (below) have small mouths that measure 50 percent or less of the distance measured between the eyes.
**Image courtesy of CITES Identification Guide - Sturgeon and Paddlefish, Canada Ministry of Environment, 2001
Range:
Shortnose sturgeon are restricted to the east coast of North America, from the
St. John River in New Brunswick, Canada, to the Indian River in Florida. In
Georgia, shortnose sturgeon are known to inhabit the Savannah, Ogeechee,
Canoochee, Altamaha, and St. Mary’s Rivers.
Reproduction:
The shortnose sturgeon's life history is complex. Much of its spawning
behavior and early life stages are still not fully understood. The shortnose
sturgeon is semi-anadromous, migrating from salt water (brackish) to spawn in
freshwater.
Shortnose
sturgeon have very specific spawning requirements. Spawning always occurs in
fresh water, and will generally occur within
a 1- to 3-week period in late winter and early spring, depending upon water
temperatures. If environmental conditions are not acceptable, shortnose sturgeon
will not spawn, resorbing their eggs and milt (sperm). Females only spawn every
3 to 5 years while males spawn every year to every other year. Age of sexual
maturity varies between sexes and between southern and northern populations.
Males reach maturity in approximately 3 years in southern rivers to 12 years in
northern rivers, while females range from 5 to 12 years, respectively).
Females lay between
40,000-200,000 eggs that hatch in approximately 13 days. Newly-hatched fry are
poor swimmers and drift with the currents along the bottom. As they grow and
mature, the fish move downriver into the most brackish parts of the lower
Ogeechee River.
Reason for
Decline: Shortnose
sturgeon populations in North America have declined due to overfishing, loss of
habitat, limited access to spawning areas (dams) and water pollution.
History in
Georgia: The number of
shortnose sturgeon present in Georgia waters prior to the 1990s is unknown. It
is likely that shortnose sturgeon caught in the shad and Atlantic sturgeon
fisheries were kept or sold, but not recorded.
Interesting
Facts:
Bottom feeders, shortnose sturgeon eat a variety of organisms. Using
their barbels to locate food and their extendable mouths to then vacuum it up,
they eat sludge worms, aquatic insect larvae, plants, snails, shrimp, and
crayfish.
Sturgeon are
among the oldest living species of fish. They have retained many primitive
characteristics, suggesting what fish may have looked like during the age of the
dinosaurs. The almost two dozen species of sturgeon can only be found in the
Northern Hemisphere. Seven of these species occur in North America.
Sturgeon are
occasionally seen jumping clear out of the water (breaching). It is unknown why
sturgeon breach, although it has been suggested that they may be attempting to
rid themselves of parasites.
Among fishes,
sturgeon are very slow-growing and long-lived. Once they reach adult size,
sturgeon have no natural enemies except humans. The largest recorded shortnose
sturgeon, a female weighing over 90 pounds, was captured in the St. John River
in Canada.
Protective
Legislation: Federal
- Endangered Species Act of 1973.
What You
Can Do: As a citizen of
Georgia, the best thing you can do is to:
Be
an advocate for clean water and be a conserver of the freshwater you use
everyday.
Encourage
municipalities to adopt the best technologies in the treatment and discharge
of sewage and in the placement and operation of landfills.
Encourage
the establishment of vegetative buffers along streams and river corridors
and stress the importance of not developing in the flood plain of our rivers
and streams.
Get
involved in Georgia’s Adopt-A-Stream program
Join a citizen’s river “watchcare” group like the Canoochee Riverkeepers, Inc.
If
you know of someone who catches a sturgeon with a rod and reel or with a
gillnet, have them return it to the water alive and unharmed.
Become familiar with various fish species by consulting identification keys and pictures before going fishing. Return all live sturgeon to the water after capture. All dead specimens should be reported to the Georgia Department of Natural Resources, Coastal Resources Division (CRD). It is illegal to keep any shortnose sturgeon taken in Georgia waters. If you catch or observe a sturgeon, please report it to the CRD office in Brunswick (912-264-7218). Documented reports of sturgeon smaller than 18 inches are extremely rare, and all sightings of these small sturgeon are especially sought by the CRD.