Sawfish in Florida are spinning and dying
The population of the smalltooth sawfish, a rare and endangered species that can be found around Southwest Florida and the Keys, has been declining for decades. And now they’re spinning and whirling in death spirals, and no one knows why.
The Florida Fish and Wildlife Conservation Commission (FWC) has been tracking reports of “abnormal fish behavior” in the Keys. Sawfish and other marine creatures have been spotted spinning and whirling, and 28 sawfish deaths have been documented, according to a March 27 FWC statement.
“Based on fish necropsy data to date, there are no signs of a communicable pathogen, and specimens were negative for bacterial infection,” the statement says.
National Oceanic and Atmospheric Administration (NOAA) Fisheries announced that with its partners it will be launching an emergency response this week in an attempt to rescue and rehabilitate smalltooth sawfish affected by whatever this is to help prevent more losses.
“It’s important to note that active rescue and rehabilitation are not always effective in saving stranded animals,” said Adam Brame, NOAA Fisheries’ sawfish recovery coordinator. “However, it can still give us critical information to learn about the nature of the distress.”
There are five species of sawfish in the world, and one of them – the smalltooth sawfish – is the only one found in Florida. Sawfishes belong to the family Pristidae, derived from a Greek term meaning “saw.”
Sawfish look and swim like somewhat flattened sharks, but they’re really a type of ray since they have gill slits and mouths on the bottom of their bodies. They’re known for the “saw,” a long, flat, rostrum with 21 to 30 unpaired teeth on each side.
Smaller sawfish that live close to shore near river mouths or tidal creeks range from 3 to 6 feet long, although larger deepwater sawfish can get up to 16 feet long and weigh an estimated 800-1,000 pounds. Juvenile sawfish tend to live in brackish water within a mile of land.
They have been protected from harvest in Florida since 1992, according to the FWC, and in 2003 they became the first marine animal to be added to the endangered species list under the Endangered Species Act. Coastal development and accidental capture diminished the population, NOAA said.
Scientists do not know why the sawfish are spinning. When fish swim in circles and even turn upside down, it’s called whirling.
“Some fishing guides started seeing these whirling fish around Big Pine Key,” Mike Parsons, a Florida Gulf Coast University professor and ciguatera expert, said in February.
No disease or bacterial infection has been found. The waters have been tested for dissolved oxygen, salinity and temperature, with no luck so far. No red tide toxins have been found in the water as well.
The Florida Department of Environmental Protection is testing more water samples and the FWC has sent 52 fish and 12 smalltooth sawfish to the University of South Alabama for analyses.