A mysterious occurrence has been observed in the waters off the Florida Keys, where dozens of fish species, including the endangered sawfish, have been seen spinning and whirling for months. Despite this unusual behavior, there doesn't seem to be any threat to humans, according to the head of a marine laboratory and aquarium.
Michael Crosby, president and CEO of Mote Marine Laboratory, stated that no abnormal water quality parameters have been detected by environmental health agencies monitoring the area. He mentioned, "This seems to be some kind of an agent that is in the water that is negatively impacting just the fish species."
Mote Marine Laboratory is working in collaboration with the National Oceanic and Atmospheric Administration to assist in the emergency response to this phenomenon.
Crosby mentioned that his team has collected tissue samples from distressed sawfish in the hopes of aiding scientists in determining the cause of this spinning behavior.
Although the terms spinning and whirling are commonly used to describe the abnormal behavior, Crosby noted that each affected fish is displaying slightly different behavior patterns.
Fishing in the area remains open, but the Florida Fish and Wildlife Conservation Commission cautions against harvesting distressed or dead animals. It is also advised to avoid swimming in areas where dead fish are present.
What could be causing the spinning and deaths?
Authorities are still investigating the cause of the unusual behavior, with speculations ranging from toxins to parasites.
"It almost seems as if it is a neurological response to some kind of agent," mentioned Crosby. "The scientific community has not yet identified a definitive cause."
No evidence of a contagious pathogen has been found, and tests for bacterial infections have come back negative, as stated by the Fish and Wildlife Conservation Commission. Scientists have ruled out factors like dissolved oxygen, salinity, pH, or temperature as the reason behind the unusual behavior and deaths. Water samples have also tested negative for Red Tide toxins.
Various aquariums and laboratories collaborating with NOAA will be responsible for housing and rehabilitating sawfish, including Mote Marine Laboratory.
Once rescued, the sawfish will undergo observation in quarantine facilities, with the ultimate aim of releasing them back into their natural habitat after rehabilitation.
Which fish species are being impacted?
According to NOAA, at least 109 sawfish have been affected, with 28 documented deaths so far.
"We suspect that total mortalities are greater, since sawfish are negatively buoyant and thus unlikely to float after death," Adam Brame, NOAA Fisheries' sawfish recovery coordinator, said. "Given the limited population size of smalltooth sawfish, the mortality of at least two dozen sawfish could have an impact on the recovery of this species."
Sawfish, which can be found in shallow, coastal waters, are an endangered type of ray — a fish type that has no bones, according to NOAA. Instead, sawfish skeletons are made of cartilage.
Sawfish can grow to be 16 feet long and weigh several hundred pounds. The affected sawfish have been between 7 and 14 feet in length, according to NOAA.
Florida officials say other types of rays and fish with bones are also being impacted by the strange spinning. Some of the affected species are: Atlantic stingray, bonnethead shark, goliath grouper, gray snapper, gray triggerfish, lemon shark, nurse shark and scaled sardine.
