Jumping Sturgeon

As the mist swirls from the tannin stained Okefenokee Swamp water, prehistoric behemoths lurk below waiting to “maim”, “strike”, “clobber”, and “attack."  Lacking teeth, they utilize their sheer size and sharp bone-like protrusions against us humans.  Weighing up to 220 pounds and reaching lengths of eight feet, the stealth attackers have struck people in boats traveling at 40 miles per hour.  Boaters beware, Gulf sturgeon are out to get you!

Tim Ross

Collisions between wildlife and vehicles are a common occurrence, just take a look at the side of the road on your way home this evening.  But how many times has a fish jumped up and hit you while driving in a boat? 

Recent headlines exclaim Maim!, Strike!, Clobber!, and Attack!, inferring the highly threatened fish are the aggressors and that the fish are fighting back.  The words grab attention (just look at the title of this article), but do not accurately characterize these docile animals.  When removed from the water for research, the sturgeon often lie motionless in the boat, as if being out of water calms them (check out the picture below).  One is not able to witness their true power until returning them to the water.

The author conducting research with a Gulf sturgeon from the Suwannee River, Florida.

Gulf sturgeon are anadromous fish that overwinter on the shallow shelf in the Gulf of Mexico, then migrate into rivers to spawn, ranging from the Florida panhandle to Mississippi.  Within the rivers, it is not uncommon to see more than 20 sturgeon jumping up to six feet out of the water over the course of the day, often with a re-entry worthy of a 10.0 from the judges of a belly flop contest.  Unlike the invasive Asian carp in the Mississippi drainage that jump as a response to boat motor noise, the Gulf sturgeon seem to jump randomly.

The Suwannee River is at the far East of the Gulf Sturgeon's current range (USFWS)

Why sturgeon jump out of the water is one of those age old questions that falls under the same category as the question of "Why do men have nipples?"  In the end, sometimes we scientists have to throw in the towel and accept that we don't know why or take an educated guess.  People speculate sturgeon jump for communication, others postulate it is to shed parasites or attract a mate, whereas a part of me wants to believe it may just be because it is fun.

Sharp scales called "scutes" line the body of Gulf sturgeon (Associated Press)

The Suwannee River, a slowly meandering undammed river originating on the border of Florida and Georgia in the Okefenokee Swamp, flows into the Gulf of Mexico along Florida’s Big Bend and boasts the largest population of Gulf sturgeon, estimated at over 10,000 individuals.  The last commercial fishing operations on the Suwannee for the caviar producing Gulf sturgeon were halted in the mid 1980s, and it was listed as Threatened under the Endangered Species Act in 1991 (the Atlantic sturgeon, the Gulf's closest relative and fellow jumper, was just listed as Endangered last week).  With an increasing population of large jumping fish, and an increasing number of boaters traveling at high speed, a higher frequency of collision was only inevitable.  Each year, an average of 9 injury-causing collisions are reported.

A close call with a Gulf sturgeon (University of Florida IFAS)

Unfortunately for the fish and people, these collisions can cause serious harm.  In 2007, a woman riding a jet ski lost four fingers, almost lost her tongue, and suffered severe skull fractures during a collision with a sturgeon on the Suwannee.  Others have suffered broken legs and concussions, and in one instance a person drowned when thrown from their boat.  As for the fish, they are often returned to the water, most likely having incurred blunt force injuries, but their ultimate fate is unknown.

(Florida Fish and Wildlife Conservation Commission)

The Florida Fish and Wildlife Conservation Commission has produced signs and campaigns to make people aware of the danger, but collision numbers continue to rise.  Similar to manatee zones, it may be necessary to create areas of reduced speed during peak sturgeon jumping (May - August) to help protect not only boaters, but also the threatened fish from serious injury and death. Leave a comment below describing how you have spread awareness on angler and boater dangers.  Tell us about any resolutions that you or others have proposed or enacted to prevent those dangers as well.  

-Patrick Cooney

Further Reading: 

Why do sturgeons jump?  Insights from acoustic investigations of the Gulf sturgeon in the Suwannee River, Florida, USA 

Living With Gulf Sturgeon: Map of confirmed strikes, Awareness Materials, Press, and FAQ