Sei whale spotted off Scotland

21/07/2011 14:52:18 Mystery sighting intrigues international Scientists
July 2011. Aerial photos taken by a Scottish paramedic of a large whale between Islay and Gigha off the west coast of Scotland have intrigued international scientists on both sides of the Atlantic. On balance they believe the sighting is most likely to be of a very rare Sei whale (Balaenoptera borealis).

Aerial photo
The story began when Danny Kerr and a team from the Scottish Ambulance Service based at Clyde Heliport were flying to Islay to pick up a patient. The pilot spotted a whale and Danny, an HEMS Paramedic, was able to pick up a camera and take a photograph of the surfacing animal as they went past. They were flying at about 500ft.

Unable to identify the animal himself, Danny contacted Sea Watch whose Research Director Dr Peter Evans was also puzzled by his description and the only picture of it from above the surface. He sought independent views from two other experts in species identification, both from the US - Dr Phil Clapham, co-author of Sea Mammals of the World, published in 2002, and Dr Tom Jefferson, co-author of another identification guide Marine Mammals of the World, published in 2008.

Danny said: "There is always excitement on board when the team spots a school of dolphins or other marine animals. This time I was lucky, there were no patients on board and I had a camera to hand and was able to get some shots. When I got home I looked at the pictures and my first impression was a humpback because I thought the pectoral fins were white but due to its body shape and broad tail, I then thought it looked more like a fin whale which is when I contacted Sea Watch."

Potential Sei whale sighting off Scotland. About the Sei whale: -Adults weigh 20-30 tons -Females measure up to 14.5 m and males up  to 19.5m -They can live up to 65 years -They can swim up to 55km hour -They have a relatively shallow dive

Sei, Fin or Minke?
Dr Evans said: "This was a very important sighting and the picture has proved vital. We ruled out humpback whale because of the slim body shape and smooth back but I didn't understand how its pectoral fins could be white until Tom mentioned that from above these can appear very light. We then considered whether it could have been a fin whale (its large size - 20 metres or more ruled out Minke whale), which would itself have been unusual for the waters, but the picture showed that the dorsal fin curved backwards and was relatively large, two features that fit Sei whales but not fin whales. The three of us independently concluded it was most likely to be a Sei whale."

Not only are Sei whales extremely rare, and protected internationally, but they are one of the species that scientists know least about. They are usually spotted singly or in pairs and feed on schooling fishes, small crustaceans, other invertebrates, including squid.

8 sightings in 50 years
There have been only eight confirmed sightings in Scotland in the last 50 years, some of which may have been of the same individual: in July 1980 there was a report off Handa Island; in Aug 1993 off Out Skerries in Shetland; in Sept 2006 off Greenstone Point at the entrance to Loch Ewe; in June 2007 at St Kilda; in June and October 2008 near Gairloch; in July 2008 east of Stronsay and in July 2010 off Auskerry, Orkney. All but the July 2010 Auskerry sighting have involved single animals, the latter being a sighting of two.

13,500 Sei whales alive
It is thought there may be only around 13,500 Sei whales in all of the North Atlantic. Those in the eastern North Atlantic winter off North-west Africa, Spain and Portugal and in the Bay of Biscay, and then migrate northwards primarily to summering grounds north of Shetland, and around the Faroes, northern Norway, Bear Island and Svalbard. Their numbers were severely depleted by whaling and fishing.

National Whale and Dolphin Watch - August 5th to 7th
Sea Watch is appealing for members of the public to send in their sightings of all whales, dolphins and porpoises, particularly during National Whale and Dolphin Watch that takes place from August 5- 7. Details of how to take part in the national watch, which will occur across the Scottish, English Welsh and Northern Ireland coastlines and coastal waters, are on their web site www.seawatchfoundation.org.uk Sightings and photos can also be sent to sightings@seawatchfoundation.org.uk

Sea Watch is a marine conservation research and education charity that works to help develop effective conservation policies with the UK Government and other national and international bodies. Understanding the distribution, strength and diversity of cetacean populations is vital to their work.