The safety of Manatees, the official marine mammal of Florida, is becoming a matter of concern for marine conservationists as the ‘gentle giants’ are subject to killing by watercraft collisions more than any other marine mammal. In Florida alone, 20-25% of Manatees die due to watercraft collisions. Death may result from propeller wounds, impact, or crushing. Most Manatees have scars from thousands of boats constantly hitting them. Research from Florida’s Fish and Wildlife Research Institute reveals that one out of every four Manatees has 10 or more scars from watercraft strikes. In fact, Manatee scars are so commonplace, researchers use them as a method of individual identification.
Realizing the importance of endangered Manatees for the ecosystem, the Florida Fish and Wildlife Conservation Commission (FWC) has established rules for their protection and developed an efficient waterway marker system in Manatee zones. There are laws enacted to slow down boats in Manatee habitats and boat speed zones have been enforced that help restrict the speed and operation of vessels likely resulting in boat-related mortalities.
Manatee is a large aquatic mammal with an egg-shaped head, flippers, and a flat tail. Manatee has been an endangered species since 1966. These creatures are mainly found in the West African, West Indies, and Florida waters. Over 6000 Florida Manatees are severely affected due to large-scale die-offs from red tide and cold stress, human-related impacts, and loss of important winter habitats. Florida Manatees were first protected through Florida State Law in 1893. In 2016, the U.S. Fish and Wildlife Service downgraded the Manatee’s ESA designation from ‘endangered’ to ‘threatened,’ but in 2021 the status was again changed to ‘endangered.’ Watercraft collisions lead to pain, stress, behavioral changes, increased energy expenditure, decreased mobility, decreased swimming efficiency, weakened immune system, and decreased reproductive output among Manatees.
All listed species of Manatees are vulnerable to extinction from the threat of loss of warm water habitat, lack of food, vessel strikes, entanglement in marine debris, entrapment in water control structures, and harassment. Two of the biggest threats are -
New developments along waterways have resulted in poor water quality which in turn has led to declining of seagrass abundance. Run-offs from sewage, manure, and fertilizer have polluted the water and caused algal blooms, some of which are toxic and can kill Manatees if they feed on the grass.
Manatees face extreme risk of boat strikes because they live in shallow, slow-moving water which is warmer and perfect for the growth of seagrass, the staple food of these herbivores.
Manatees can be hit by a boat, personal watercraft, barge, or other types of vessels because:
Organizations across the globe are doing their bit to protect Manatees and their aquatic habitat for future generations. Following are a few steps in that direction:
Powerboat operators must maintain a safe distance of about 50 feet from a Manatee. Boaters can avoid harming Manatees with their boats in many ways, some of which are mentioned below.
Signs Promote Manatees Preservation
Mounting prominent Manatee signs in areas with high traffic such as a dock walkway, dock master offices or restrooms is an excellent way to educate and alert boaters to the presence of Manatees in the waterways or to report any injuries. They are constant reminders to stay alert and follow rules for everyone in susceptible zones.
Signs help create Manatee Zones and ask boaters to reduce speed and put off a minimum wake (the v-shaped wave created by the boat's displacement as it passes through the water).
Signs for dredge, tugboat, and workboat operators must be replaced when faded, damaged, or outdated. Multiple signs shall be considered for large facilities or those with multiple docks and separate walkways that are a considerable distance apart.
The Florida Manatee Program requires that the signs must not face the water, and must never be attached to pilings or navigational markers in the water except for the “Caution Boaters” or “Idle Speed while in work area” signs that face the water for temporary awareness during in-water work. Occasionally, larger signs are affixed to bridge fenders, seawalls, or other embedded waterway structures while smaller signs are used in appropriate situations where there are smaller bodies of water, canals, boat ramps, etc.
Saving endangered Manatees has become the focus of several researchers - to be able to best preserve them and their habitat. Research by the Florida Atlantic University has dived deep into Manatee behavior and proven that Manatees hear well at higher frequencies (16,000 and 18,000 kilohertz). Contrary to popular belief, the study states that slowing down boats may make it more difficult for Manatees to detect and locate approaching boats. Slower boats have a lower frequency of around 0.05 to 0.8 kilohertz, while increasing how long it takes for boats to pass through Manatee habitats.
It is unlawful for any person, at any time, intentionally or negligently, to annoy, molest, harass, or disturb any Manatee. Manatee viewers must keep their distance and observe the animals passively. Signs can be used to make snorkelers, divers, and visitors on boats understand that they should NOT:
Feeding or playing with Manatees is not only dangerous for their health but also because the Manatees can become used to having people around them. Such activities can alter their behavior in the wild, perhaps making them lose their inherent fear of boats and humans, increasing their chances of being harmed even more. Violators may face a fine of $500 and/or imprisonment for up to 60 days or $50,000 and/or one year in prison (at the federal level). Florida government can pursue prosecution under federal law in case of extreme harassment, leading to the death or injury of a Manatee.
