Another three endangered sawfish have turned up dead this spring as scientists continue to investigate toxic algae they suspect is killing the fish, bringing the total to nine this year.
Last week, three sick smalltooth sawfish grounded themselves in shallow waters around the Florida Keys. One died, said Florida Wildlife Research Institute biologist Tom Matthews. Since December, state wildlife biologists had received 50 reports as of mid April for sightings of the rare fish in distress.
READ MORE: Rare sawfish turning up dead — again — in South Florida waters
Another 104 reports were called in for other species showing signs of spinning, similar to a mass event last year that killed dozens of species along with the sawfish. The total number of dead sawfish now stands 65.
The rare, prehistoric-looking fish are found mostly in South Florida in U.S. waters. They were thought to be nearing extinction until the Florida population was discovered in the 1990s and laws put in place to protect them. They were added to the Endangered Species List in 2003, becoming the first marine fish added to the list.
While they spend much of their time in deeper waters, they travel to shallow waters to have their pups, historically in waters on the Gulf Coast. Until the die-off, they were rarely seen, making the spectacle of their chainsaw-like snouts all the more impressive. Sawfish can grow up to 18 feet long.
Early last year, they started turning up dead, mostly in the Keys, in alarming numbers after a blistering ocean heat wave. Scientists suspect the summer heat wave set the stage for a bottom-dwelling algae to spread as steamy waters killed coral, sponges and other plants and animals.
An all-hands-on-deck investigation led lawmakers set aside $2 million to look into the cause, with the Bonefish Tarpon Trust receiving most of the funding to collect and analyze data from water around the Keys and in Biscayne Bay. At the height of the event, scientists detected the tiny algae Gambierdiscus at elevated levels and suspect that triggered the neurological disorder exhibited by the fish.
Necropsies were performed on both sawfish as well as other species, which also found other toxins. Gambierdiscus has not been found at high levels this winter., Matthews said.
Biologists are asking the public to report signs of fish in distress to help with their research. Reports can be made online here or by phone to 1-800-636-0511. Be sure to provide the location (GPS coordinates are best) along with the number and kind of fish, if possible, and contact information.
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