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FISH BUSTERS' BULLETIN
October 2006
By Alan Huff, Bob Wattendorf and Ted Hoehn
Fish and Wildlife Conservation Commission
Surgin’ Sturgeon
To a fisheries biologist, every fish species has
a unique appeal, but the sturgeon’s prehistoric nature can be
fascinating to anybody. The Gulf sturgeon is a subspecies of
Atlantic sturgeon, which along with the shortnose sturgeon, are
native to Florida.
This season, Gulf sturgeons have again made
headlines for their millions-of-years-old antics of jumping out
of the water. During the spring and summer of 2006, at least
eight boaters were injured by incidental collisions with these
amazing high flyers that can leap 6 feet out of the water. As a
result, the Florida Fish and Wildlife Conservation Commission
(FWC) posted signs, cautioning boaters to go slow in areas where
Gulf sturgeon are known to congregate and jump.
Gulf sturgeon have been federally listed as a
threatened species since 1991 and protected by Florida law since
1984. These protections were needed to counter the effects of
habitat loss caused by river damming and commercial
overharvesting. Development, surface mining and declining water
quality continue to threaten the Gulf sturgeon today.
Alan Huff, an FWC research biologist, conducted
some of the pioneering research on Gulf sturgeons. He said they
can live more than 40 years, weigh 200 pounds and approach 8
feet in length. Sturgeons can’t be mistaken for any other family
of fish due to their five rows of armor-like scutes (large, bony
scales). Like sharks, their internal skeleton is made of
cartilage. They have whisker-like barbels, extendable
under-slung sucking mouths and shark-like tails.
Females spawn at about 7 years old, males at 5.
A 200-pound female can produce 40 pounds of eggs (more than a
million) per year, and sturgeon eggs are the raw material for
highly valued caviar. However, females may skip reproduction for
a year or more. When all is aligned in early spring – proper
river water temperature, flows and levels – female sturgeons
eject eggs to be fertilized by males to sustain the population.
FWC freshwater fisheries biologist Jerry
Krummrich was accompanied recently by “National Geographic”
photographer Stefan Lovgren, FWC Law Enforcement Officer Rodney
Boone and FWC public information coordinator Karen Parker on a
trip to photograph jumping sturgeons. The 200-mile Suwannee
River contains the largest concentration of Gulf sturgeons, but
they reproduce in other rivers around the Gulf of Mexico to the
Mississippi River. They spend nearly eight months in the rivers
where they were spawned, scarcely feeding or not at all.
When Thanksgiving rolls around and Gulf water
temperatures cool, some very hungry sturgeons move off shore to
go on a feeding and growth binge. They consume worms, small
crustaceans, mollusks and other invertebrates as they cruise
along the Gulf of Mexico’s bottom. They use their barbels to
sense concentrations of food and extend their suction-hose-like
mouths to suck up enough food to survive their next foray into
Florida’s Gulf Coast rivers the following spring, when they
again pretty-much stop eating.
For a recent article and an upcoming “National
Geographic” television show, Lovgren asked numerous experts why
sturgeons jump. Among the speculative answers he and others have
received are:
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For joy
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For social interactions and to communicate
with other sturgeon
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To knock off pesky parasites
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To flush muck out of their mouths and gills
after bottom feeding
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To avoid perceived predators (although what,
other than gators and manatees, might be big enough to
startle them is unclear)
In the Apalachicola River, since the mid 1950s,
the Jim Woodruff Lock and Dam and diminished water flows from
Georgia have cut off one of the major reproductive grounds for
this threatened species. Populations appear to be increasing in
the Suwannee and Choctawhatchee rivers. The Apalachicola River
population appears to have a more cyclical increase and decrease
in year-classes, perhaps related to the dam’s water-release
schedule and water flow rates.
Sturgeon fossils date back to the dinosaur era.
After the continents split into their current configurations
many millions of years ago, sturgeon species were confined to
the northern hemisphere, and Atlantic and Gulf sturgeon
populations evolved into subspecies.
Sturgeon flesh and eggs provided an important
source of food and commerce for thousands of years. Today, human
interactions with Gulf sturgeon are restricted to observation
and research. Harvest is prohibited.
If you find a dead sturgeon, please report it to
1-800-367-4461 (or e-mail TagReturn@MyFWC.com), especially if
there is a tag on it, so scientists can learn more about this
species’ life habits and distribution. To report collisions with
jumping sturgeon, call 1-888-404-FWCC (3922). Hopefully,
conservation stewardship will enable us to coexist with Gulf
sturgeons for a long time to come, and maybe we’ll really learn
why they jump.
This column includes information from FWC
research,
FishBase.org,
news.nationalgeographic.com,
fws.gov/endangered and
pgap.uchicago.edu. See
MyFWC.com/fishing/updates for more Fish Buster columns.
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