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© I.N. Visser/WDCS |
Dolphins are mammals like us, they are highly social and have a great sense of curiosity. Bottlenose dolphins occur worldwide, except for polar regions. Most live in family groups, usually based around adult females, which can contain from just 2 or 3 dolphins up to 500 of them! They are often seen bowriding, surfing and breaching and are able to leap several metres out of the water. They can sometimes be seen playing ‘games' with things such as seaweed, coral or other animals. Dolphins can communicate with each other up to a distance of 3km away! They have a complex range of sounds with different meanings. Here is a taster of dolphin language: Lots of rapid clicks = food is nearby Lots of whistles = I'm lonely Squeaky whistle = I'm scared Chattering jaw = go away Slapping tail = now I'm really cross! |
Sources of Info: Whale and Dolphin Conservation Society website and literature: The Mammal Society website: Brixham Seawatch: www.brixhamseawatch.fsnet.co.uk Seawatch Foundation: Adopt a Beach: |
© Westcountry Publications |
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Around the world, bottlenose dolphins come in many sizes. They can range from 1.9 to 4 metres in length and the dolphins around the UK are some of the largest in the world. Dolphins never sleep. While one side of their brain rests, the other side keeps them swimming near the surface so they can breathe. In the wild, females normally live longer than males and can reach 50 years old or more. Like bats, dolphins use echolocation (or sonar) to catch their prey of fish, squid and crustaceans. They send out rapid clicking noises and listen to the echoes that bounce back from objects – the echoes create a ‘sound picture' and the dolphins can tell how far away and what size and shape the objects are. Different bottlenose dolphins from around the world have been seen to use different specialist techniques for catching some of their food. For example, groups of dolphins have been watched working together to herd fish up towards the surface, into a tight bundle, where the dolphins can easily pick them off. In South Carolina (USA) dolphins chase fish onto the shore and then roll up on the beach to catch them. In the Gulf of Mexico , they are seen ‘fish-whacking'; stunning fish by flicking them in the air with their tail flukes and then picking them up from the water surface. In the town of Laguna , Brazil , fishermen catch fish with the help of the dolphins. The men stand on the beach with their fishing nets in the water and the dolphins drive the fish towards the beach. As they get near, the dolphins roll over on the surface and the men take this as the signal to throw their nets. Any escaping fish swim straight into the mouths of the waiting dolphins – cool teamwork! |
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Dolphins under threat Many of us have a special affection for dolphins and yet they are suffering greatly because of us and their numbers are declining. Despite being protected by law in UK and European waters they are threatened by: • Marine Pollution • Accidental capture and drowning in fishing nets • Disturbance and harassment by people in boats. Lindy Hingley of Brixham Seawatch is trying to spread the word that drowning in fishing nets is a major problem in the English Channel because of the number of factory trawlers over 500 horsepower and the growing number of boats ‘twin trawling' – this is where a huge net is slung between 2 boats, is trawled for a long distance and scoops up anything and everything that gets in its way. The dolphins are attracted by the shoals of fish in the nets and get trapped themselves, unable to surface for air they frantically try to escape and die a brutal death. In the winter of 2001 / 2002 at least 120 dead dolphins were washed ashore on the South Devon and Cornish coast, with several hundred washed ashore on the Brittany coast in France . This death toll is probably only a fraction of the total number of dolphins drowned because most of the bodies sink to the seabed. |
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Disturbance by water craft is a growing problem, especially here in the Bay, too many boats surround the dolphins and get too close – often this is because people just don't realise the stress they are causing. The result is the dolphins are frightened away and are less likely to return. Boats/ Jet skis etc should slow right down – max 5 knots , never get closer than 100m and only stay for a short while (it is actually an offence to disturb or endanger dolphins under the 1981 Wildlife and Countryside Act). We are lucky to have one pod, including Benty, as regular visitors in the Bay. Most recent sitings were in October 2002. Occasionally, around the UK , bottlenose dolphins that seem to prefer to be solitary and to favour contact with humans are reported. Fungi the dolphin has been living in Dingle Bay , Ireland for years. George the dolphin has been making regular contact with people along the south coast of England throughout 2002 and has visited Torbay several times (insert picture of George with Clare at Brixham). Unfortunately some people have assumed that he is tame when he is still very much a wild animal, they have tried to tail ride him and he has butted them and has exhibited some rather ‘over friendly' sexual behaviour. Having the chance to meet George is a fantastic experience but it is much better to stay out of the water and watch him from land or in a boat (stopping 100m away and letting him approach of his own free will). |
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To report sightings of dolphins, porpoises, or basking shark in and around Torbay please ring the Trust's Seashore Centre, Goodrington on 01803 528841 Or Brixham Seawatch: 01364 631578 / 01803 752253 – link to website: www.brixhamseawatch.co.uk If you would like to do something about dolphin deaths in fishing nets, write to your local MP expressing your concern and asking him to pass on your letter to the Fisheries Minister. |
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