Scientists Track the Gulf Sturgeon Stampede

Gulf sturgeon being weighed on shore, you can clearly see the rows of protective scutes.October 20, 2011: Fall weather brings cooler temperatures to the rivers and streams that surround the Gulf Coast, sending a signal to sturgeon that it’s time to move on. This month, Gulf sturgeon begin their annual migration from coastal rivers to the ocean. That means NOAA scientists are close behind, working from Louisiana to Florida to capture and tag the fish before they reach the open Gulf of Mexico. 

Gulf sturgeon spend the warmer months in coastal rivers, the Pearl, Pascagoula, Blackwater, Escambia, Choctawhatchee, Yellow, Apalachicola , and Suwannee where they do not eat.  Instead they use their energy to lay eggs on the silt-free rock and rubble of the river bottom. As water temperatures cool in the fall, the sturgeon leave these spawning grounds and head for the brackish and marine waters of the Gulf of Mexico and its estuaries. They spend these cooler months using their uniquely adapted mouth to sift through the mud and muck and feed on crabs, worms, and other small marine life.

NOAA scientist inserting an acoustic tag during a training session before the studyIn 2010, NOAA Fisheries—in partnership with the US Fish and Wildlife Service, US Geological Survey, Delaware State University and the University of Mississippi –initiated a five-year study of Gulf sturgeon across their range between Louisiana and Florida to collect data and better understand population
changes, their movement between rivers, and their average death rates.  Last year, a total of 328 Gulf sturgeon were captured, and 174 new fish were implanted with acoustic transmitters. Some fish were recaptures, and other fish were tagged only with a passive integrated transponder tag, otherwise known as “PIT.”  The PIT tags  emit a radio frequency from the fish that help permanently identify it for study.  

Now in the study’s second year, scientists will surgically implant 100 more acoustic transmitters with a five-year battery life into Gulf sturgeon.  These transmitters send out signals detected by remote receivers to track fish as they swim from river to sea and back again. Scientists will use the data to better
The barbels and special mouth on this sturgeon help it find food buried on the bottomunderstand the migrations of Gulf sturgeon and develop more effective
protection measures for the species. 

Gulf sturgeon are federally listed as threatened under the Endangered Species Act. They can live up to 60 years, and they have remained relatively unchanged since they first appeared in fossil records 200 million years ago.

The sturgeon’s skeleton is mostly made of cartilage, similar to sharks.  Also akin to sharks, the top lobe of a sturgeon’s tail is longer than the lower lobe, which is called a heterocercal tail.

For more information on efforts to recover Gulf sturgeon and other species, and how you can help, please visit http://go.usa.gov/0qu and for more on Gulf sturgeon, visit http://go.usa.gov/8Ap. You can also contact Jonathan Shannon at jonathan.shannon@noaa.gov.