ST. PETERSBURG, Fla. — A perplexing ailment causing prehistoric smalltooth sawfish, which are endangered, to spin uncontrollably and often perish in Florida’s waters has reemerged, with over 50 fatalities reported last year, wildlife authorities announced on Wednesday.
After a nine-month pause, there have been 22 incidents of the peculiar spinning behavior observed in sawfish around the Florida Keys since December, according to the state’s Fish and Wildlife Conservation Commission. Six deaths have been recorded in this recent outbreak.
The root of this issue, which resulted in at least 54 sawfish deaths last year, remains uncertain. The agency disclosed that assessments for parasites, bacteria, viruses, and over 250 chemicals, in addition to investigations into issues like toxic red tide, failed to reveal any conclusive causes.
“Scientists discovered some subtle changes in the brain tissue of affected fish, but further research is required,” the agency mentioned in a release.
Sawfish, related to rays, skates, and sharks, are notable for their long, flat snout lined with teeth. Having existed for millions of years, sawfish can live for decades and reach considerable sizes, sometimes up to 17 feet (about 5 meters). They were once plentiful along the southeastern U.S. coastline but are now primarily found off southwestern Florida and the Keys island chain due to shrinking habitats.
Since December 2023, over 500 incidents of spinning sawfish and other species have been recorded.
In response to the initial fatalities, state legislators allocated $2 million to investigate the sawfish deaths around Biscayne Bay near Miami, Florida Bay, and the Florida Keys. Part of these funds assists local fishing guides in water sampling and related tasks, as reported by the FWC. Additionally, there is a hotline for reporting spinning or disoriented fish.
One hypothesis suggests that an extensive heat wave last year, largely linked to climate change which also caused coral bleaching, may have altered the ocean’s algae, particularly near the seafloor where sawfish frequently reside. Sawfish, like rays, have their gills underneath, often drawing in water from the bottom.
“Scientists have identified several algal toxins in fish tissues, and these are currently being studied as possible causes,” said the FWC.
The smalltooth sawfish was placed on the U.S. endangered species list in 2003. In Florida, intentionally capturing, harming, or disturbing sawfish is prohibited.
In recent years, Florida’s waters also witnessed significant manatee fatalities as pollution decimated their seagrass diet. State and federal entities resorted to feeding tons of lettuce to manatees that congregated during winter near a power plant for two years, leading to a partial recovery, with 565 deaths reported in 2024 compared to a record 1,100 in 2021.
