Marine Mammal facts: this is a group encompassing whales, dolphins, manatees, dugongs, seals, sea lions and walrus, sea otters and polar bears.
These are animals like humans, giving birth to live young and relying upon air to breathe, however they spend most or all of their time in the water.
These are charismatic species, capturing the hearts of most people. The role they play in maintaining the ecosystem is vital. Either as keystone species controlling prey numbers from the ‘top down’ or by returning nutrients to the system through their poop.
Marine mammal facts: some species have been hunted almost to extinction, with some populations still endangered. Some species are managing to bounce back, despite the fact that the hunting and exploitation of marine mammals still continues to this day in some parts of the world.
Cetaceans, e.g. whales and dolphins and Sirenians e.g. manatees and dugongs, are fully reliant upon water for their existence spending all of their time in the sea. This is where they eat, sleep, and give birth.
Seals, sea lions and walrus’ are semi-aquatic, spending most of their time in the water but ‘hauling out’ – returning to land in order to mate, breed and molt.
Polar bears and sea otters are much less adapted to ocean life, spending majority of their time on land or within reach of the coast.
Marine mammal facts: each species diet varies greatly, as well as distribution around the world and favoured habitats. The way these animals communicate, forage and navigate also differs between groups.
Cetaceans use echolocation: the use of sound; in order to communicate, find prey and navigate. This means they are highly vulnerable to noise pollution. Whereas some of the polar species are highly vulnerable to retreating ice shelves, the warming of the ocean and reduction in habitat. These species are highly vulnerable to by-catch as part of fisheries exploitation, and marine traffic represents a major threat too, with vessel strikes causing many deaths. Ocean plastic is a huge issue, with entrapment and ingestion being evident as cause of death in multiple cases. Chemical pollution is also a major threat, as most of these species are at the top of the food chain the build up of chemicals remains in the systems of these animals, particularly the build up of toxic heavy metals in the large fatty blubber layer.