Cetacean are mammals that lives in the ocean that includes whales, dolphins, porpoises and related forms that have torpedo shaped nearly hairless bodies, paddle shaped forelimbs but no hind limbs, one or two openings at the top of the head and a horizontally flattened tail for movement.
Many species of whales and dolphins are known to inhabit the waters around the Dutch Caribbean islands, including orcas, humpback whales and sperm whales. At least 32 different species of marine mammals have been documented in the Caribbean region, but there is surprisingly little known about these intelligent and social creatures. The species that have been documented include:
- Six species of Baleen whales (Mysticeti) –
- 24 species of toothed whales (odontoceti)
- One sirenian ( West Indian Manatee)
- 3 species of Pinnipeds ( seals)
- Baleen whales
Baleen whales are some of the largest animals on earth yet they feed on some of the smallest animals in the ocean.There are 12 baleen whale species.
Baleen whales are born with baleen plates instead of teeth.
Baleen whale hunt for food using a method known as filter feeding, they capture their food by swimming towards their prey with their mouth open and use their baleen bristles to filter large amounts of fish, krill, shrimp, octopus, various crustaceans and other sea sediments from the water.
- Toothed whales
Toothed whales also consists of all species of dolphin and porpoise. As the name suggests toothed whales are born with teeth and are generally considered the hunters of the cetacean family. Species such as the killer whale and sperm whale are known to be aggressive hunters and many of the species are known to hunt in cooperative groups or teams to isolate and capture their prey.
For the most part toothed whales are smaller than their baleen whale counterparts with the largest of the toothed whale family, the sperm whale, growing to lengths of up to 20.4 meter. and weighing over 40823 kilograms.
Sirenia, commonly sirenians, are also referred to by the common name sirens, deriving from the sirens of Greek mythology. This comes from a legend about their discovery, involving lonely sailors mistaking them for mermaids.
Sirenians are an order of fully aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. Four species are living, in two families and genera. These are the dugong and manatees.
Dugong (family Dugongidae), also known as “sea cow”, is a close relative of manatees.
There 3 manatees species (family Trichechidae): Amazonian manatee, West Indian manatee and African manatee.
The West Indian Manatee (Trichechus manatus) is the largest member of the order of Sirenia and can weigh up to 1500 kilograms, although usually somewhere between 400 and 800 kilos.
All manatees have a split upper lip. They use both parts of the lip to help put food in their mouths. Because grasses aren’t very nutritious they feed on huge quantities. This has also given them a very slow metabolism.
All the three species of manatee are listed as ‘vulnerable to extinction’ by the IUCN. Although they do not have any natural predators, the increase in human activity has reduced its habitat in the coastal marsh areas and manatees are often injured or killed by collisions with powerboats. Manatees like warm, shallow, coastal estuarine waters, and because of that they often congregate near power plants, where the water is warmer.
There are three Families of pinnipeds. First are the earless, or true seals, (Phoncidae) which consist of 19 species. Next are the eared seals (Otariidae) which has 14 species including sea lions and fur seals. Last are the walruses (Odobenidae). Most of these animals are common in the Arctic and Antarctic because their primary prey is more available there than in warmer water.
This is a diverse group despite its physiological similarities. Pinnipeds vary greatly in size and the way they utilize the marine environment. They consume a variety of different food sources, including fish , squid, cuttlefishes and octopuses), and certain species have also been known to eat krill, crabs, and shellfish. Feeding behavior and diet may differ widely even within a specific population.
The Caribbean Monk seal was a species native to the Caribbean and is now extinct. The last sighting of the monk seal was in 1952. In 2008 the species was declared extinct. The species was hunted for their fur and oil and overfishing of their food sources is the reason for extinction.
Main threats to marine mammals are:
A. Fisheries interactions:
– incidental capture in nets or hooked on line
– Targeted hunts
– Ecological effect from competition for food
B. Habitat degradation because of:
– Coastal Development
– Wide range of pollutants and nutrients from land and sea.
Yarari Marine Mammal & Shark Sanctuary
In September 2015 The State Secretary for Economic Affair, Mrs. Sharon Dijksma, publicly announced the estabishment of the Yarari Marine Mammal and Shark Sanctuary which encloses all the water around Saba and Bonaire including the Exclusive Economic Zones.
‘Yarari’ is a Taino Indian word for ‘a fine place’.