Marine mammals, December 1991 – February 1992

In recent years, the Harbour Porpoise Phocoena phocoena has returned in very small numbers in Dutch coastal waters as a winter visitor. Between December and April, particularly at sites in Noord-Holland, lucky observers will be able to observe this small cetacean. Winter 1991/92 was no exception, with 11 sightings (15 animals in all) during Dec-Feb (NvdH, Camperduin, Bergen, Egmond; location encircled in figure 1). There were no sightings in Zuid-Holland, nor at the Wadden Sea islands. Most porpoises were solitary animals, with a couple and one herd of 4 being the only exceptions. Newspapers reported odd sightings between the Wadden Sea islands this winter, but no official reports were received by us. Offshore reports include sightings from MV Solo, late November 1991, in the central and northern North Sea (TP, TG), and sightings from cruises along the Netherlands coast and well into the German Bight by MV Navicula (MFL). Few cetaceans were spotted from MV Solo in the southern and central North Sea (a single Harbour Porpoise at the Dogger Bank; figure 1), but sightings of 8 Killer Whales Orcinus orca at 61°35’N, 01°16’E and 4 and 8 Pilot Whales Globicephala melas at approx. 61°29’N, 01°29’E did compensate a lot (TG, TP). Navicula’s cruises along the Dutch, German and southern Danish coast resulted in Harbour Porpoises off the Wadden Sea islands, near Helgoland and on the Amrum Bank near Sylt (figure 1). Two unidentified dolphins were spotted just north of Ameland (just 2 tall dorsals seen briefly; MFL, HO, BB). In all, between 12 Jan and 31 Jan 1992, 36 porpoises were observed in herds of 1-4 individuals from this ship (MFL, HO, MH, BB). There were no sightings south of Texel during the February cruise along the mainland coast.