Manatees in the Ecosystem

Manatees, also known as sea cows, are an integral part of the tropical wetland's ecosystem located in regions of the U.S., South America and the Caribbean. An ecosystem is a complex biological relationship between living organisms, such as plants and animals, and abiotic factors, including chemicals and the physical environment. The manatees' role in their ecosystem is so significant that that their presence is indicative of a healthy ecosystem, according to a study in Tropical Conservation Science.

  1. Environment

    • Manatees live in both saltwater and freshwater and are often found in estuaries, bays and along coastal shorelines. They prefer shallower waters because, like other mammals, they must breathe surface air to survive. Manatees inhabit places with abundant amounts of vegetation, as this is their sole food source. Manatees also migrate along the coasts as they seek out warmer waters during the winter.

    Feeding and Elimination

    • Manatees are herbivores, and can eat up to 15 percent of their body weight per day; a manatee close to 3,000 lbs. could potentially eat around 400 lbs. of vegetation. Thus, manatees' eating habits affect the population of sea grass and other aquatic plants. Another environmental effect of manatees' digestive habits is that through defecation, manatees release nitrogen and other chemicals into the water. The nitrogen is a necessary nutrient for plants and the chemicals balance the pH of the water. The relationship between these environmental factors must stay balanced for an ecosystem to remain healthy. Thus, manatees play an important role in cycling nutrients through their ecosystem.

    Life Cycle

    • Manatees traditionally had few natural predators, and lifespans of up to 60 years. Death was typically the result of natural causes such as diseases, but human interference has significantly shortened manatees' lifespans. Historically, a long lifespan was balanced by a long, reproductive cycle. Manatees are incapable of reproduction until they are five; after that they only give birth once every three to five years. Baby manatees, or calves, stay with their mothers for the first two years. If the mother is injured or killed, it also engenders the calf. Currently, the manatees' long, reproductive cycle and slow ability to repopulate contributes to endangerment.

    Threats

    • Manatees are currently on the verge of extinction. As of January 2011, it is estimated that there are less than 5,000 manatees left. Close to 500 manatees were found dead in 2006 alone, according to the World Wildlife Fund. The majority of these deaths were the direct result of human action -- manatees were struck by fishing boats, sickened by pollution, or swallowed fishing hooks and lures. Without conservation efforts, it's estimated the species could become in extinct in the next 40 years. Manatees' endangerment jeopardizes not just their species, but also the entire ecosystem they inhabit.