Many fish species living around the Florida Keys archipelago in Florida, USA, are exhibiting highly unusual behaviors before dying, raising concerns among scientists who are struggling to find explanations.
This strange phenomenon was first discovered by American diver Gregg Furstenwerth in November last year while he was diving in the waters off the Florida Keys.
During his dive, Gregg observed a grouper swimming awkwardly, continuously rolling upside down in circles before stopping and dying. Notably, Gregg later encountered several fish from different species displaying similar behaviors before dying.
Intrigued and curious about these events, Gregg used his underwater camera to capture footage of the fish’s behaviors. He then shared these videos on social media to ask the online community about the strange behaviors of these fish.
Video of fish exhibiting unusual behaviors before dying off the coast of Florida. (Video: Gregg Furstenwerth).
These videos caught the attention of scientists, prompting an investigation. Recently, the investigation revealed that up to 44 different fish species within a 56 km (35 miles) radius around the Florida Keys have been affected by this strange phenomenon, including the small toothy fish, one of the species at risk of extinction.
The common characteristic among them is that they swim in circles or continuously roll over before dying.
However, scientists have yet to determine the cause of this unusual phenomenon in fish.
“Everyone wants to know what has caused these fish around the Florida Keys to behave so strangely, but we have not been able to provide an answer. We will do our best to identify the cause of this anomaly to propose suitable solutions,” marine scientist Alison Robertson shared.
“It’s puzzling that such a strange phenomenon can persist and affect so many different species,” Robertson added.
Although the exact cause remains undetermined, scientists are trying to rule out unreasonable explanations.
The small toothy fish, a species at risk of extinction, has also been affected by this strange phenomenon, resulting in at least 21 individuals dying. (Photo: Doug Perrine).
Initially, many scientists suggested that “red tide” might be the cause of the unusual fish behaviors. “Red tide” refers to an algal bloom phenomenon that occurs in natural environments with large quantities of algae in rivers or oceans. Depending on the type of algae, the surrounding water can change color, possibly red, green, or purple…
Some types of algae can produce toxins during their growth. When the algae die, these toxins are released into the water, harming other organisms in the ecosystem and causing mass deaths among marine life.
However, scientists reported that they did not observe the occurrence of “red tide” around the Florida Keys. Additionally, they did not detect any abnormal high temperatures, low oxygen levels, or parasites in the affected fish.
“Fish dying is a common occurrence. But in this case, we cannot explain the reasons behind the mass fish deaths. That is the peculiarity of this phenomenon,” marine ecology expert Michael Parsons from the University of Florida stated.
Scientists are currently actively researching to pinpoint the exact cause of the unusual behaviors exhibited by fish before dying.
