Manatees are herbivore mammals with an average life span of forty years in the wild. The Florida manatees (Trichechus manatus latirostris) are also known as sea cows and can weigh anywhere from four hundred and forty pounds to thirteen hundred pounds and inhabit the coastal waterways around Florida. There are three different species of manatees and they are distinguished by the geographic region they inhabit. Manatees live in different parts of the world such as “the North American east coast from Florida to Brazil, the Amazon River and the west coast and rivers of Africa” (National Geographic). These marine mammals are listed as endangered species and their decline is due to threats such as collision with watercrafts, potent marine neurotoxins …show more content…
The red tide dinoflagellate Karenia brevis produces marine neurotoxins known as breve toxin and have killed large amounts of fish. They have also been known to cause illness to humans through consumption of shellfish or inhaling toxic aerosols. Breve toxin can act as a vector and transmit illness from one organism onto another through the food chain. Fish and sea grass can contain large amounts of breve toxins that are detrimental to marine life. As a result, manatees are susceptible to toxins from the red tide and have resulted in many deaths. For example, thirty four endangered manatees in Florida died in the spring in 2002 with low amounts of breve toxins present. In a prior event where one hundred and forty nine manatees died, lung pathology revealed the presence of breve toxins. “[T]he absence of similar pathology excluded the possibility of poisoning through aerosol exposure, and the high toxin concentrations measured in the stomach contents indicated that the toxin was from a dietary source” (Flewelling, 755). The presence of breve toxins in sea grass and fish contaminated food have affected those on the upper trophic levels. It has resulted in large numbers of casualties in marine mammals, primarily affecting Florida manatees and …show more content…
The Florida Manatee inhabit the Mid-Atlantic States of North Carolina and Virginia during warm summers and in the fall. They have “a low metabolic rate and high thermal conductance, which limits their ability to maintain core body temperatures in cold waters” (Cummings, 126). Manatees rely on warm waters to regulate their temperature but the drop in water temperature in the fall is threatening the existence of these marine mammals. When temperatures are above twenty degrees Celsius during June to October sightings were more common. On the contrary, in the fall when temperatures drop to 1.35 C/d the sightings of manatees decreased. If exposed for prolonged periods of time in temperature water below sixteen degrees Celsius, the manatees will experience cold stress. “Cold stress describes a suite of clinical conditions and disease processes, including emaciation; infectious diseases of the skin and gastrointestinal tract; serous fat atrophy; lymphoid depletion; and compromise to metabolic, nutritional, and immunological functions that can lead to death” (Cummings, 127). The Manatee depends on warm water from the tropics in order to survive and they cannot survive in water temperatures below twenty degree Celsius. “The lower end of the Florida manatee’s thermo neutral zone, or the lowest temperature range at which it does not need to use active metabolism to stay warm, is 20 to 23° C”