21 endangered smalltooth sawfish deaths spur fishkill investigation

Writer: Paul Dolan
Published: Updated:
Crews from the U.S. Sawfish Recovery investigating mysterious fishkill. CREDIT: U.S. Sawfish Recovery

Scientists are urgently searching for answers to understand why smalltooth sawfish are dying at an alarming rate or have been seen acting bizarrely at the shoreline.

According to the Monroe County Board of County Commissioners, the Florida Fish and Wildlife Conservation Commission has 21 documented smalltooth sawfish deaths in 2024.

Tagging smalltooth sawfish in the Florida Keys. CREDIT: FSU Coastal & Marine Lab

To help FWC authorities uncover details about the fish mortality events at Biscayne Bay, Florida Bay and the Florida Keys, commissioners secured $2 million in state funds.

The FWC is not going into this research blind. FWC is eliminating some of the possible causes of the fishkill based on results from recent necropsies:

  1. There have been 21 total documented smalltooth sawfish deaths since the first was reported on Jan. 30, 2024.
  2. There are no signs of a communicable pathogen and specimens were negative for bacterial infection. Additional sawfish tissues are still being processed for analysis.
  3. Dissolved oxygen, salinity, pH and temperature are not suspected to be the cause of the fish behavior or kills.
  4. To date, Red Tide toxins (brevetoxins) produced by Karenia brevis have not been detected in water samples.
  5. At this time, the cause of the abnormal behavior and mortalities is not known, and efforts to collect and analyze samples are ongoing.

“We know there is a lot of frustration in the community not knowing what is going on,” said Monroe County Commissioner Michelle Lincoln. “We are all extremely concerned about our ecosystem and what is causing this to happen.”

The FWC will work side by side with nonprofit organizations to collect vital information to get to the bottom of the mysterious fishkill.

“We are fully supporting our State scientists and experts in working as quickly as possible to discover what is happening,” said Monroe County Mayor Holly Merrill Raschein.

Smalltooth sawfish death investigation. CREDIT: U.S. Sawfish Recovery

Videos of the endangered species acting strangely at the shoreline in the Florida Keys have been spreading on social media.

The Calusa Waterkeeper retweeted a map pointing out the 60 reported smalltooth sawfish sightings FWC received between Jan. 30 and March 5.

Lake Okeechobee has been releasing water into the Caloosahatchee for the past few weeks. This has caused some concerns over water quality in Southwest Florida. It’s unclear if it is related to the fishkill or what is happening to the endangered smalltooth sawfish.

Folks from the Florida State University Coastal and Marine Laboratory posted to social media about a recent trip to the Florida Keys for routine smalltooth sawfish sampling. Crews set a new winter trip record by tagging 11 large juveniles and adult sawfish.

The acoustic trackers will last ten years. Receivers will log the date and time whenever one of the tagged sawfish swims past them.

According to the National Oceanic and Atmospheric Administration, authorities believe the species’ decline is due to overfishing, habitat loss and the fact that the species takes a long time to reproduce.

Smalltooth sawfish research. CREDIT: FWC

Despite historically having habitats from Texas to New York, the smalltooth sawfish has one final stronghold on the planet: from Charlotte Harbor to the Florida Keys, including Everglades National Park.

Click here to learn more about the species from NOAA.

You can report a sawfish sighting to FWC by calling the hotline at 844-472-9347. You can also report a fish kill to the FWC by clicking here.

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