We were welcomed aboard RMV Scillonian III to carry out the VSAS August seabird survey on this route. Volunteer Seabirds at Sea (VSAS) is a citizen science initiative which recruits and trains volunteers to collect high quality seabirds at sea data from vessels of opportunity around the UK. Volunteers are trained by JNCC to conduct surveys using the European Seabirds at Sea (ESAS) method, which is widely recognised as being the 'gold standard' for seabird data collection. MARINElife coordinates the VSAS volunteers in England.
Also, on board the Scillonian III, along with the usual Island visitors, were some very keen birders (with very long lenses!) hoping to see the Red-footed Booby recently spotted on Bishop Rock. This is a bird of the tropics and subtropics and this is only the second to be seen in Britain, this misplaced individual was still on the Bishop Rock to be enjoyed.
However, the return crossings from St Mary’s also provided some great views of four species of shearwater including Great Shearwater, which breeds in the South Atlantic, mainly on the Tristan da Cunha island group. In their non-breeding season from May to November, they cross the equator to spend their winter feeding in the North Atlantic.
We also recorded a large number of Cory's Shearwater, which breeds in the Mediterranean and on the Atlantic islands of Madeira, Canaries and the Azores. They are usually seen off the UK at this time of year but this autumn there have been particularly large numbers present in the southwest approaches. To record a total of 176 on a MARINElife survey is exceptional.
We were pleased to record seven Balearic Shearwater, one of Europe's rarest seabirds, which again breeds in the Mediterranean but moves into the NE Atlantic at this time of year, the English Channel and Celtic Sea being an important area for them.
Situated on the fly-bridge of the Scillonian III we were kept busy recording presence or absence of seabird species in timed intervals. However, numbers of Common Dolphin were doing their level best to distract us from our main task, with small groups rushing with determination towards the bow and then performing acrobatics down the side of the ship. We made a note of the ones that appeared in our survey patch to starboard but had to ignore the ones to port. However, the passengers and crew of the Scillonian III appreciated their antics. A single Bottlenose Dolphin also put in a brief appearance.
Our thanks go to the Isles of Scilly steam ship company staff and the Master and crew of the Scillonian III for their hospitality and invaluable assistance during this survey. The data collected by VSAS surveys can be used to inform seabird conservation and could feed into related areas of work, such as offshore development, fisheries management, and possible response to pollution incidents.
Maggie Gamble and Judith Tatem, Research Surveyors for MARINElife (Registered Charity No. 1110884; Registered Company No. 5057367)
Weather
Outward – wind SW 3-4, early fog then sunny, excellent visibility, swell <2m
Return – wind SW 3-4, sun and cloud, excellent visibility
Summary of sightings:
Marine Mammals
Common Dolphin Delphinus delphis 38
Bottlenose Dolphin Tursiops truncatus 1
Seabirds
Gannet Morus bassanus 93
Fulmar Fulmarus glacialis 30
Balearic Shearwater Puffinus mauretanicus 7
Manx Shearwater Puffinus puffinus 473
Great Shearwater Ardenna gravis 3
Cory’s shearwater Calonectris borealis 176
Kittiwake Rissa tridactyla 9
Mediterranean Gull Larus melanocephalus 6
Great Black-backed Gull Larus marinus 8
Herring Gull Larus argentatus 6
Sandwich Tern Thalasseus sandvicensis 10
Larus sp. 1
Auk Sp. 3