Scientific Journal of the BirdLife Hungary

A Magyar Madártani és Természetvédelmi Egyesület tudományos folyóirata

Ornis Hungarica. vol.12-13. (2003) p.105-115.

A low-cost, year-round seabird monitoring programme in the English channel & Bay of Biscay: preliminary results 1995-2001
T. M. Brereton, C. Weir, M. Hobbs and A. D. Williams

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In 1995, the Biscay Dolphin Research Programme established a monthly, year-round seabird and cetacean monitoring programme in the western English Channel and eastern Bay of Biscay, using the P&O Portsmouth cruise-ferry the Pride of Bilbao and volunteer surveyors. On each four-day survey trip bird recording was made during all daylight hours, enabling the whole of the route to be sampled over much of the year. Over the 5.25 year recording period 44 seabird species were recorded, with more than 100 000 seabirds counted in approximately 50 000 km of search effort, spread over 85 ICES rectangles (measuring 15 latitude by 30 longitude). Shelf waters of the northern Bay of Biscay were found to have presumed important numbers of wintering Northern Gannet Morus bassanus and Great Skua Catharacta skua at relatively high densities. A number of other species including Divers Gaviiformes, gulls Laridae and auks Alcidae were present at lower abundance. During the summer, these shallow waters supported moulting populations of Mediterranean Shearwater Puffinus yelkouan (mauretanicus) at the northern edge of their range and European Storm-petrels Hydrobates pelagicus, which are scarce in north European waters at this time of year. A number of seabirds rare elsewhere in north European waters were regularly recorded during the late summer and autumn period in shelf-edge and deep water areas of the Bay of Biscay, including Little Shearwater Puffinus assimilis, Cory s Shearwater Calonectris diomedea, Great Shearwater Puffinus gravis, Grey Phalarope Phalaropus fulicaria, and Sabine s Gull Larus sabini. Spectacular numbers of Great and Cory s Shearwaters were found in most years of survey, with loafing flocks of hundreds of birds seen on numerous occasions. Recent methodology enhancements have been made to improve the quality of monitoring data, and further improvements are proposed. The BDRP surveys have demonstrated how volunteers and ferries can be used to generate low-cost, quantitative data in areas where large -scale systematic surveys are unlikely to be carried out. The results of such surveys may have considerable conservation and policy relevant implications, particularly in the designation and year-round management of marine Important Bird Areas.