Officials in Florida reported a significant rise in the mortality rate of smalltooth sawfish, an already critically endangered species. Over the past seven days, six of these rare creatures were found dead along the Florida coast, marking a stark increase in fatalities amid an ongoing and perplexing die-off that has puzzled scientists for months.
Smalltooth sawfish, characterized by their shark-like appearance and distinctive chainsaw-like mouth, are members of the elasmobranch group, which includes rays, skates, and sharks. Normally, the loss of about five mature adults per year is recorded, primarily due to accidental entanglement in fisheries. However, this year has seen an alarming surge, with 38 sawfish fatalities reported by the Florida Fish and Wildlife Conservation Commission.
The exact cause of this unprecedented spike in sawfish deaths remains a mystery. Compounding concerns, reports from divers and anglers have described other marine species exhibiting unusual behavior, including spinning in circles instead of swimming. Some sawfish have also been observed spinning before succumbing to death.
The phenomenon of spinning fish was first noted in fall 2023, coinciding with the uptick in sawfish mortalities observed since January 2024. While the connection between these events remains speculative, experts from the Florida Fish and Wildlife Conservation Commission and the Mote Marine Laboratory are actively investigating possible links.
On April 5, a distressed sawfish was discovered in Cudjoe Bay, Florida Keys, prompting biologists to transport it to a temporary tank at the Mote facility for observation and stabilization. Subsequently, the sawfish was relocated to a more permanent Mote quarantine facility for rehabilitation.
The unusual behavior of marine life extends beyond sawfish, with reports of over 200 incidents involving more than 30 species exhibiting abnormal swimming patterns. While concentrated primarily in the Florida Keys, similar occurrences have been reported as far north as the Miami area.
The smalltooth sawfish, granted federal protection under the Endangered Species Act in 2003, was once widespread in the Gulf of Mexico and along the East Coast but is now predominantly found off the coast of Florida due to dwindling numbers.
As scientists grapple with the mystery of these distressing events, theories abound regarding potential causes. While tests for toxins have yielded mostly negative results, an increase in gambierdiscus algae, known to produce neurotoxins harmful to fish and humans, has been observed. The proliferation of gambierdiscus, favored by warmer ocean temperatures linked to climate change, poses a potential threat to marine ecosystems.
For Gregg Furstenwerth, a veteran diver in the Florida Keys, the situation evokes feelings of unease and urgency. Witnessing marine life behaving erratically has left him deeply concerned about the future of the ecosystem.
"With no definitive answers yet, the uncertainty surrounding this crisis is unsettling," Furstenwerth remarked. "If left unchecked, it could spell disaster for our marine environment as we know it."
