Whales and Why They Beach Themselves

Whales belong to the group cetecea, which includes whales, dolphins and porpoises. Although these species depend upon water for their very survival, they are in fact mammals with lungs, and as such must regularly rise to the ocean surface in order to breathe air. They are conscious breathers therefore, they can decide when to breathe. This means that when sleeping, whales cannot fall into an unconscious state for too long as they need to be concious to break the surface and breathe. Like other mammal species, whales also have a small amount of hair, feed milk to their young, and are warm-blooded. As such, the layer of fat called blubber which is located beneath their skin acts as insulation against cold ocean waters. Whales inhabit every ocean, and are excellent navigators by nature.

Whales can be divided into two suborders:

1) Baleen whales tend to be the larger species of whale and include; blue, grey, and bowhead species. They are filter feeders, and use a bristle-like fringe (called a baleen) to filter out microscopic plankton, small fish and crustaceans. They often migrate long distances either alone, in groups, or in pods (depending on the species) from cold-water feeding grounds to warm-water breeding grounds.

The largest animal ever known to exist on Earth is the blue whale, which can weigh up to 200 tons; the equivalent of 33 Elephants!

2) Toothed whales have teeth as opposed to a baleen, and use echolocation to sense their environment. Species include; sperm, white, killer, pilot and beaked whales. Their diet consists of fish, squid, and marine mammals, including other species of whale. They often hunt in groups, migrate together, and share young-rearing duties.

Why do these mysterious, magnificent creatures so often strand themselves?

Cetacean stranding is a phenomenon in which cetacean species such as whales strand themselves on land. Although mass strandings have been recorded since 300 B.C., it is clear that these are occuring more frequently and in larger numbers. Scientists are unclear as to what is causing the strandings, however there have been many theories as to why they could occur:

• Water pollution - leading to sickness/poisoing (e.g. gas, acid, daily plastic waste)

• Man-made sonar - causing confusion, and disorientation

• Natural diseases

• Changes to the Earth's magnetic field - may interfere with the whales biological navigation system.

• Climate change - changes in tides, melting icebergs, and shifting food sources may force relocation which could result in whales entering shallow waters.

• Following the group - whales are very social. In some cases, they may follow a sick/injured dominant individual into shallow waters, where they may then all become beached. Additionally, the pod may attempt to come to the aid of a beached individual and in the process endanger themselves.

Often when beaching occurs, a large number of volunteers, and organisations come to the aid of these magnificent creatures. However, it is not always possible to re-submerge the whales due to their sheer size and weight, which often requires heavy machinery to mobilise them.

Ocean Alliance is an organisation which has been involved in whale research and conservation since 1970. They aim is to conserve whales through research and education, by working with external organisations to gather information on whales and ocean life, and using this data to advise educators, policy makers and the general public on ocean health and pollution. Ocean Alliance and other organisations like this are leading the way in conservation and gaining a better understanding of the ecology of whales, which may in the future provide answers as to why whales beach themselves.

#Whale #marine #ocean #conservation