Protecting the manatee

US researchers have developed a unique acoustic system designed to keep manatees from being injured or killed by flood gates and boat locks.


Researchers at the Harbor Branch Oceanographic Institute at Florida Atlantic University have developed a unique acoustic system designed to keep manatees from being injured or killed by flood gates and boat locks.


Their so-called manatee acoustic detection sensor protection system is composed of an array of unique acoustic transmitters and receivers that provide non-contact detection of manatees as they pass through the gates of the lock.


When a manatee blocks the acoustic beams, which they cannot hear, the gates stop and remain open long enough to allow them to pass through safely.


The researchers at Harbor Branch Oceanographic Institute recently received a $5.8m federal contract from the US Army Corps of Engineers to install the system in southern Florida on the six navigation locks around Lake Okeechobee.


Among these are Moore Haven lock at Clewiston and the Port Mayaca lock where the St. Lucie River meets Lake Okeechobee, a waterway that links the Atlantic Ocean to the Gulf of Mexico.


‘We installed a prototype acoustic system about ten years ago in the St. Lucie lock. Since then, we have redesigned the system with underwater sensor cartridges. The device is now smaller, cheaper, faster and easier to operate,’ said Larry Taylor, project manager for manatee protection systems at the Harbor Branch Oceanographic Institute.


Manatees live in shallow, calm rivers, estuaries, saltwater bays, canals, and coastal areas. They move from fresh to salt water easily and the Florida manatee frequents most areas of Florida. It is estimated that there are approximately 3,000 Florida manatees in existence today.


According to the Florida Fish and Wildlife Conservation Commission, locks or gates have caused at least 191 manatee deaths in Florida since 1974.