Mysterious 'Spinning Fish' Cases Decline in Florida Keys, But Research Intensifies

Bonefish & Tarpon Trust Leads Multi-Agency Eff ort to Unravel Cause and Protect Vital Fisheries

MIAMI, FL [Feb. 12, 2025] – Bonefish & Tarpon Trust (BTT), whose mission is to conserve bonefish, tarpon and permit fisheries through science, education and advocacy, is providing an update on the ongoing “spinning fish” phenomenon in the Florida Keys. There is some promising news: reports of spinning fish are down this winter compared to last year. However, the underlying cause remains under investigation by BTT and partners.

Since fall 2023, more than 80 fi sh species in the Florida Keys have exhibited abnormal 'spinning' behavior, losing equilibrium and swimming erratically. The phenomenon has aff ected numerous species, including the endangered smalltooth sawfish.
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Collaborative Research Efforts
In response to the phenomenon, BTT, in collaboration with the Lower Keys Guides Association (LKGA), launched a comprehensive research initiative in January 2025 funded by $1.75 million awarded to BTT by the State of Florida through the Florida Fish and Wildlife Conservation Commission (FWC). This funding supplements existing resources and allows BTT to expand its ongoing research into the causes of spinning fi sh, a project that began more than a year ago. The initiative brings together an interdisciplinary team of experts from Florida International University (FIU), Florida State University (FSU), the University of South Alabama (USA), Florida Gulf Coast University (FGCU), the Florida Department of Environmental Protection (FL DEP), and the Florida Fish and Wildlife Conservation Commission (FWC).

“This critical research to understand the unprecedented 'spinning fi sh' phenomenon and its impact on Florida's fi sheries is only possible because of the generous support from the Florida Legislature," stated Jim McDuffi e, BTT President and CEO. "The unwavering commitment of our partners is also essential as we work together to piece together the complex puzzle of what is causing this issue.”

Thanks to this funding, researchers are better equipped to understand the causes and scale of the event. BTT and its partners are utilizing a variety of approaches to investigate the phenomenon including: ● Neurotoxins that may have contributed to abnormal behaviors and mortalities

● Harmful algae that produce neurotoxins
● Mapping habitats that support harmful algae
● Fish and invertebrate community impacts
● Animal movements and exposure to neurotoxins

Findings to Date
While the research is ongoing, initial fi ndings strongly suggest a link between elevated levels of Gambierdiscus algae and the spinning fi sh phenomenon. Researchers have found evidence of the potent neurotoxins produced by this algae in aff ected fi sh tissues and water samples.

Importance of Ongoing Research
This research is crucial because it is helping BTT and partners gain a deeper understanding about the issue. The work being done is critical for not only identifying the cause of the spinning fish phenomenon but also for developing science-based recommendations to mitigate future impacts on the Florida Keys’ ecosystem.

BTT is also working closely with local fi shing guides, leveraging their on-the-water knowledge through a Rapid Response Network to track the spread and intensity of the phenomenon. This network of experienced guides enables BTT to quickly identify affected areas and collect vital fish and water samples for testing.

BTT encourages the public to report any unusual fish behavior to FWC or LKGA, or call 844-4-SAWFISH. Public reports have been an essential resource for investigations into this event.

Stay up-to-date on the latest findings and updates on the spinning fish investigation by visiting BTT.org and following BTT on Instagram.

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