Wed May 23, 2012
Dr. Melissa Gibbs, Stetson University – Invasive Catfish and the Manatee
In today’s Academic Minute, Dr. Melissa Gibbs of Stetson University explains how an invasive species of catfish is making life hard for the manatees of Florida.
Melissa Gibbs is an associate professor of biology and Director of the Aquatic and Marine Biology Program at Stetson University. Her research interests include the ecology of springs and visual processing in fish. She Holds a Ph. D. from the University of Delaware.
Dr. Melissa Gibbs – Invasive Catfish and the Manatee
Imagine a night when you most need a deep, restful sleep. Instead, you spend hours swatting at mosquitos buzzing around your head. In the morning you wake up feeling hungry, stressed, and sleep-deprived. That’s been the reality for the endangered Florida manatee since armored catfish became a prominent invasive species in Florida waters.
Loricariid catfish are native to the Amazon basin, and arrived in the US via the aquarium trade about 50 years ago. They have only become a real pest over the past decade, as they burrowed into river banks to nest, consumed large quantities of algae, and swarmed manatees trying to rest in spring runs.
My students and I have been studying the effects of these catfish on the Volusia Blue Spring manatee population. Manatees feed in the adjoining St. Johns River, but during winter, cold river water can literally chill manatees to death. Blue Spring is used as a thermal refuge from the river, but the lack of manatee food in the spring means manatees must balance the need to feed in the river with the need to warm up & conserve energy in the spring. Unfortunately, catfish in the spring use their suckermouths to attach to and graze algae from the manatees’ skin. So, instead of rest, manatees expend precious energy trying to dislodge the catfish. Just as you or I would swat at a pesky mosquito, the manatee twitches and flips to throw off the harassing catfish.
Manatees are already stressed by human activity, pollution and cold temperatures, and since stressors have multiplicative effects, we think harassment by catfish could have significant negative effects on the manatee health. We continue our research into basic catfish biology in the hopes that our data will help resource managers minimize the impact catfish are having on Florida ecosystems and a beloved, endangered species.