Seabirds at sea, Dec 1990 – Feb 1991 (Ship-based observations)

The Navicula was cruising off the Wadden Sea islands, mainly in search of concentrations of scoters, in Jan and Feb (HO, TP, TG, MK). MV Holland was manned in the Dec MONO, but the data are still not available (AN). In Feb, the Holland was again manned (GOK), mainly for dumping tagged grebes and ducks into the sea (NZG/NSO drift experiment), but also for some bird counts in the course of that month’s MONO. MV Tridens II was manned during its cruises for the International Bottom Trawl Survey around Shetland, off east Scotland and off east England during 29 Jan-13 Feb (BC, AS). The IBTS survey around Shetland and off the Scottish and English east coast resulted in very low densities of seabirds. Just off the Wadden Sea islands, in Jan and Feb, Guillemots and Razorbills were abundant. Mid March all Guillemots had disappeared, while only some (immature) Razorbills were left behind. Divers were numerous and besides Redthroated (most abundant) and Black-throated Divers, several Great Northern Divers were spotted (HO cs.). A massive concentration of Common Scoters was located north of Terschelling (not Schiermonnikoog, the usual place), roughly estimated at 40,000 individuals. It was quite impossible to count the birds, either from the air, or during ship-based surveys (CS, HB, HO) In March an adult male Surf Scoter was observed amongst the others.