Marine mammals, June – August 1992

A dip is was recorded in cetacean sightings from our waters, mainly because there were no ship-based surveys these months. Summer sightings from coastal sites are rather rare, and indeed, not a single porpoise was reported this summer. A rare stranding was reported near Borssele, Westerschelde, on 5 August 1992 (Hielkema 1992, Trouw, 7 August 1992, P.L. Meininger). A 4 meter long, rather fresh dolphin appeared to be a beaked whale Mesoplon spp., possibly Mesoplon bidens, which is than only the twelfth found this century on our coast. Beaked whales of this genus are deep-water species which do not normally occur in the North Sea.