Beached bird surveys, december 1987- march 1988 (NSO)

Low densities in December. The National Survey showed an overall density of 2.3/km, with few oiled birds included. Most numerous were Larusgulls (32.5%, n= 627), Eider Duck (19.1%) and Guillemot (15.6%). Extremes were a count in Zuid-Holland on 19th December (Noordwijk-Zandvoort, AS) with no birds found at all, and a count on Schiermonnikoog two days earlier with 8.2/km on a 10km stretch (AvdS and others). On Schiermonnikoog mainly Elders (29.3%), waders (14.6%) and Larus-gulls (31.7%) were found. Daily surveys by car on Terschelling resulted into 60 Guillemots caught alive (PdJ, data not included in analysis). In January 1988 an oil spill off Zeeland resulted into mass-mortality of (mainly) Great Crested Grebes, Eiders, referred to as the ”Borcea-incident“ is to be found elsewhere in this issue. Densities in other parts of the country (north of Wassenaar, Zuid-Holland) remained rather low. Mortality caused by another oil spill in Zeeland, in the Oosterschelde, on 24th January, as a result of a collission of the Dutch MV Vlaardingen and the Belgian MV Rapide Vier, was not studied by us. Also nothing is known about any mortality related to again another incident in Zeeland this month, an illegal oil spill on the Westerschelde on 28th January.