Tuesday, 31 July 2012
In Moreton Bay, Australia, two groups of Bottlenose dolphins (Tursiops species) have lived separately; living in different areas and barely communicating. They were once thought to be members of the same pod; however something caused them to separate into two. This however, has recently all changed, after a ban on trawlers in the areas. The ban has led to a 50% reduction of fishing in the bay and a huge change on the dolphin pods. They have, in fact, united to become one large pod. This is an interesting development for the dolphins, but it is important to remember that these dolphins do live in a fluid society, also known as 'fission-fusion'. They form and divide into various groups, so it will be interesting to see how long this large group lasts or whether they will divide back into smaller groups and if they do, whether it will be the same dolphins breaking off. Dolphins are a very social animal who use both sound (up to 30 different vocalisations) and body language to communicate. Pods will generally interact with each other, sometimes for social reasons, such as breeding. However, they do not always communicate for friendly reasons. Sometimes pods will fight or even attack each other sexually. It is interesting that the dolphin’s behaviour changed after fishing was reduced and no doubt further investigation into this will take place. If it is found that less fishing has a positive impact on these mammals, it is likely that this will be used in the fight to expand no fishing zones throughout the world.