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 ORCA Wildlife Surveys 2009 Wildlife Sightings |
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| Winter Dolphin Research Project Independent Marine Consultant and photographer Marijke de Boer is carrying out winter surveys for marine mammals aboard the supply vessel the Gry Maritha. Winter Dolphin Research Surveys started in January 2007 and species thus far recorded are harbour porpoise (Phocoena phocoena), grey seal (Halichoerus grypus), common dolphin (Delphinus delphis), minke whale (baleanoptera acutorostrata), bottlenose dolphin (Tursiops truncatus) and Risso's dolphins (Grampus griseus). Little is known about cetaceans (whales, dolphins and porpoises) that occur in the waters off Cornwall. There is considerable concern about the scale of cetacean bycatch (incidental entanglement in fishing gear) in the fisheries to the south of the UK. Primary evidence for the scale of the problem has come from stranded cetaceans, predominantly short-beaked common dolphins and harbour porpoises, recorded in the winter months on the English and French coasts. The significance of the impact that bycatch poses to populations is unclear as little is known about the numbers of cetaceans that frequent these waters at this time of year. Seven different species were positively identified during previous surveys carried out in the waters to the south of Cornwall since January 2004, these were bottlenose dolphin, short-beaked common dolphin, striped dolphin (Stenella coeruleoalba), harbour porpoise, Risso's dolphin, minke whale and fin whale (Balaenoptera physalus). It is important to estimate an index of density for the inshore winter common dolphin and porpoise populations by following random and fixed survey transects. Obtained photographs will enable us to study the residency of small cetaceans. In addition, we will document the surface behaviour of small cetaceans. The passage between Penzance and the Scilly's therefore offers a unique opportunity to collect information on cetaceans in a consistent and scientific manner. For more detailed reports click here for: 2009 South West Cretacean Survey . (this is a PDF file) |
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SEA LIFE SIGHTINGS 2009 The sun was shining when we sailed from St Mary’s the next day and we were soon greeted by a flock of kittiwakes. These are a small type of gull which very elegantly dips into the surface to pick up any small particle of food. We were not the only ones that had noticed this small feeding flock of kittiwakes.. suddenly a minke whale surfaced just ahead of our vessel swimming straight towards the kittiwakes. The smooth dark coloured back and tiny dorsal fin were visible for a few seconds before the whale arched into deeper waters. The next two hours were spent counting harbour porpoises which were much easier to see with yesterday’s swell now greatly reduced. With an almost glassy sea surface the little triangular dorsal fins of the porpoises were visible at great distance. Amongst all the activity a large grey seal was also seen ‘bottling’ (only the head of the seal is visible as the animal is apparently resting). Whilst crossing deeper waters a large group of seabirds (mainly diving gannets) were visible on the horizon. A large spout was seen on two occasions but it was not possible to identify the whale to species. However, it does indicate that there is a good chance the fin whales have come back again to feed in this area as witnessed last winter. The main seabird species seen were guillemots and razorbills, although the northern gannet, kittiwake, northern fulmar were also regularly seen and even one Balearic shearwater! |
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1st April 2009 Our winter research has come to an end and all results have been compiled in a preliminary report but more ‘number-crunching’ is needed to be able to present our final figures. The passage from Penzance to the Scilly Isles is affected by different tidal systems influenced by the Irish Sea, the Bristol and English Channels. This offers a unique winter feeding habitat for several species of cetacean which were observed, with variable frequency, during this study: common dolphins (in particular prior 2007), bottlenose dolphins, Risso’s dolphin, harbour porpoises, minke whales and fin whales. The majority of porpoises were seen off the Scilly Isles and a preliminary estimate for density has been calculated. Preliminary data analysis also indicates that Mounts Bay is an important habitat for harbour porpoises year-round and in particular the area off the Runnelstone. We are also, for the first time, commencing dedicated surveys onboard the MV Scillonion, in partnership with ORCA (Organisation Cetacea), to facilitate cetacean data collection between Easter and late autumn. 2009 Sea life Sightings Map. The boat-based survey data collected during the four winters study period, together with offshore winter data collected in 2004/2005 are to form part of a PhD study. The research onboard the Gry Maritha is an invaluable attribute to the PhD study as this will allow us to study the cetacean distribution in a dynamic and changing environment. We would like to thank the Isles of Scilly Steamship Group and the crew of the Gry Maritha for all their help and assistance in supporting this study! |
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