The National Oceanic and Atmospheric Administration (NOAA) is launching what the agency described as an emergency response effort in south Florida after emerging reports of smalltooth sawfish spinning, whirling and displaying other abnormal behaviors.
In a statement released last Wednesday, NOAA said that in addition to the abnormal behaviors, there have been reports of fish deaths in the lower Florida Keys, including more than 28 smalltooth sawfish as of 24 March.
The cause of the abnormal behaviors and fish deaths is not known, according to the Florida fish and wildlife conservation commission (FWC). Ongoing emergency response efforts not only involve coordinating the recovery of smalltooth sawfish carcasses for necropsies, which are animal autopsies, they also encompass collecting and analyzing water samples.
Necropsy results have so far indicated zero signs of a communicable pathogen, the FWC said, adding that the specimens tested negative for bacterial infections. Dissolved oxygen, salinity, pH and temperature also are not suspected to be the causes of the abnormal behavior and deaths.
“If the opportunity presents itself, this would be the first attempt ever to rescue and rehabilitate smalltooth sawfish from the wild,” the NOAA Fisheries’ sawfish recovery coordinator, Adam Brame, said. Brame added: “We’re hopeful for positive outcomes from these rescue attempts, and grateful to our partners for their support as we work to protect this endangered species.
“It’s important to note that active rescue and rehabilitation are not always effective in saving stranded animals. However, it can still give us critical information to learn about the nature of the distress.”
One of five species of sawfish, the smalltooth sawfish lives in tropical seas and estuaries – or semi-enclosed areas where rivers meet the sea – of the Atlantic Ocean, the NOAA says on its website.
Residing mostly in shallow, coastal waters, the smalltooth sawfish are shark-like in appearance but are actually rays with their gills and mouths on the underside of their bodies. They also have a long, flat snout edged with teeth, which resembles a saw, an appearance that gives them their name. Smalltooth sawfish mostly eat fish but may also eat invertebrates.
Populations of the smalltooth sawfish declined significantly during the second half of the 20th century due to habitat loss from coastal development and accidental capture in fisheries, according to the NOAA. As a result, the species was the first marine fish to receive federal protection as endangered.
Speaking about the recent deaths in south Florida, Brame said: “We suspect that total mortalities are greater since sawfish are negatively buoyant and thus unlikely to float after death.”
He continued: “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.”
As part of its emergency response efforts, the NOAA plans to rescue smalltooth sawfish and observe them at quarantine facilities. The agency added that its goal is to release all rescued smalltooth sawfish back to the wild once they have been rehabilitated.
