In the spirit of World Oceans Day today, watch this terrific National Geographic video about manatee-alarm research. This is something that’s so long overdue it’s almost heartbreaking, as the number of manatees in Florida continues to dwindle.
Manatees are docile, non-aggressive, slow-moving marine mammals with few natural predators. Despite this, all three extant manatee species in the world are listed as vulnerable on the IUCN Redlist of Threatened Species. The main threat to their survival is an extremely high incidence of harmful boat collisions, frequently resulting in grave injury to the manatees.
Dr. Edmund Gerstein and his team have been conducting research into this problems for 20 years. They’ve found that manatees are unable to hear at the low frequencies emitted by boat engines. Although their hearing is very good, they seem to only be able to hear at much higher frequencies. The scientists devised and tested an alarm system for boats that emits a high frequency noise underwater.
We’ve got 17 alarm runs and for those alarms we got 100% reaction, the animals reacting way before the boat gets there. And we’ve got over 65 silent runs where 97% of the time the animals haven’t reacted at all.
Hopefully this means that boaters in Florida will soon be required to equip their vessels with manatee alarms! Seriously though, watch the video, if only for the absolutely adorable footage of a manatee nomming the researcher’s hair in the water at around the one minute mark.