As you may have seen in the news recently an international cetacean conservation agreement known as ASCOBANS has now been extended to include the waters of the Isle of Man. So what exactly is this agreement, and why is it good news for us?
Well firstly ASCOBANS stands for the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas, which as the names suggests is all about ensuring good conservation for ‘small cetaceans’. Cetacean is the term used to refer to whales, dolphins, and porpoises and in this case ‘small cetaceans’ covers every species of Odonotocete, or toothed whale, except the sperm whale which is considered as one of the ‘great whales’. Here around the Isle of Man we are lucky to regularly encounter five species of cetacean, four of which are Odontocetes and so fall under this definition of ‘small cetaceans’. Those species are the harbour porpoise (Phocoena phocoena), the Risso’s dolphin (Grampus griseus), the bottlenose dolphin (Tursiops truncatus), and the short-beaked common dolphin (Delphinus delphis). We also often see minke whales (Balaenoptera acutorostrata) around the island but these are baleen, and not toothed whales, and so are not covered here.
“Migrating cetaceans regularly cross national boundaries. Their protection can only effectively be achieved by means of international cooperation. The aim of the Agreement is to promote close cooperation between countries with a view to achieving and maintaining a favourable conservation status for small cetaceans throughout the Agreement Area.”ASCOBANS
Map of ASCOBANS region - credit: www.ascobans.org
The agreement was first established in 1991, originally covering just the Baltic and North Seas, in reaction to the worrying decline of the population of harbour porpoise in the Baltic Sea, and covers such requirements as prevention of significant disturbance, particularly acoustic disturbance. The agreement was updated in 2008 to cover the North East Atlantic and Irish Sea alongside the original Baltic and North Sea coverage. Of particular interest to Manx Whale and Dolphin Watch as a research organisation, and indeed the only organisation conducting cetacean research in Manx waters, is the requirement for surveys and research which highlight the need to “(a) assess the status and seasonal movements of the populations and stocks concerned, (b) locate areas of special importance to their survival, and (c) identify present and potential threats to the different species.” When Manx Whale and Dolphin Watch began its work here over 10 years ago there was next to nothing known about cetaceans in Manx waters. Our boat based, land based, and photo-identification surveys over this time have helped us to build up a picture of which species we can see here, and has given us an indication of seasonal patterns and general habitat usage. We’ve also started to get hints of the importance of the Isle of Man to perhaps our most iconic cetacean species, the Risso’s dolphin, as we have often encountered groups containing a number of very small calves suggesting the Irish Sea and Manx waters to be especially important in the early life stages of this species. There is still so much we want to learn about the amazing cetaceans we see here, such as using our photo-identification work to examine the social structure of the groups we see, and getting more accurate population abundance estimates. Our desire to get a towed hydrophone to conduct acoustic surveys around the island is particularly related as this type of equipment can help to gain more accurate counts of the numbers of animals using Manx waters.