New red tide treatment for manatees under construction

Florida International University and the Mote Marine Laboratory are developing new, more effective ways to treat manatees exposed to toxic red tides.

With a $ 428,000 grant from the Oceanic and Atmospheric Administration's ECOHAB program, CRF and Mote are launching a three-year project to improve the veterinary care of rescued manatees by studying how the cells of their immune system react to certain antioxidants. The goal is to identify the antioxidants that may work better than the current treatment, which uses anti-inflammatory substances.

Chemist Kathleen Rein and marine immunology expert Mote Cathy Walsh lead the research team.

"The current approach is simply to give palliative care and wait until they eliminate the toxin and improve," Rein said. "This new treatment could speed up the healing process. If this treatment succeeds, it could be used with many other animals, including dolphins, turtles and birds.

Red tide toxins can compromise the manatee's immune system, causing a harmful phenomenon called oxidative stress, making the animal vulnerable to disease. Manatees can become ill or even die from eating contaminated vegetation or inhaling contaminated air.

"We are identifying which compounds are most promising to minimize oxidative stress levels so that they can be tested in a veterinary setting with these animals in the future," Walsh said. "The current and enduring bloom of the Florida Red Tide and its intense impacts on Florida manatees underscore the need for better treatments."

The current proliferation of Karenia brevis – the microscopic algae causing the Florida Red Tide – is the worst since 2005. Seven counties are currently in a state of emergency and do not anticipate the duration of the current red tide bloom.

The red tide is responsible for 10% of manatee deaths in the last 10 years. During the flowering years, this number increases to 30%. More than 575 manatees have already died this year, including 103 suspected or confirmed red tides, according to the Florida Wildlife Commission. This exceeds the annual total of 538 in 2017.

Just two years ago, the US Fish and Wildlife Service changed the status of the endangered and threatened manatee. Rein and Walsh's research, if successfully applied to veterinary care, can help prevent manatees from falling into danger again.