Mass dolphin strandings very rare, say experts

Urmee Khan, The Telegraph 9 Jun 08;

Although 'mass strandings' of dolphins are fairly rare, they do occur every year throughout the world.

Dolphins are very sociable and will communicate to each other by whistling, and in times of distress this can cause a large group of dolphins to cluster together.

According to experts, mass strandings are usually linked to natural reasons or directly caused by humans.

Dr Peter Evans, director of Sea Watch Foundation, says the strandings can happen if an older dolphin, usually a female, is sick or suffering from a disease, causing the rest of the pod to follow.

"In such circumstances, the dolphin seeks shallow water to enable it to breathe easier."

Certain types of shore and some particular coast lines are more prone to strandings than others. Shallow, sloping shores made of soft sediments can attract pods of dolphins.

Human factors responsible for mass strandings can include sea pollution and intense noise pollution from naval sonar can also be responsible for a mass stranding.

Sarah Dolman from the Whale and Dolphin Conservation Society (WDCS) said: "Earlier this year over 50 deep diving whales washed up in Scotland, Ireland and Wales and that was due to high-powered naval sonars which can cause a great deal of distress."