THE EFFECTS OF A SPILLAGE OF DIESEL FUEL ON A ROCKY SHORE IN THE SUB-ANTARCTIC REGION (MACQUARIE-ISLAND)

On 3 December 1987, the supply ship Nella Dan ran aground at Macquarie Island (54 degrees 29'S, 158 degrees 58'E) releasing about 270 000 l of oil, mostly light marine diesel, into the sea. At the time of the i ncident, many marine invertebrates were washed up dead along 2 km of s horeline. Twelve months later, the shore community was investigated us ing 1. algal and invertebrate populations of the littoral and sublitto ral rocky shore, and 2. the invertebrate communities living in the hol dfasts of the giant kelp Durvillaea antarctica, which were collected f or later examination. Investigations were undertaken at both affected and control locations. Analyses of differences in community structure involved nested ANOVA and multidimensional scaling techniques. On the rocky substrate, the effect of the spill was restricted to some biota of the lower littoral and sublittoral zones-particularly echinoderms a nd the patellid limpet Nacella macquariensis. There were differences i n cover for some algal species between locations. Within the kelp hold fasts, communities were dominated by peracarid crustaceans at control locations and by polychaetes (particularly the opportunistic groups-ca pitellids, cirratulids and spionids) at oil-affected locations. The co mmunities have recently been re-surveyed (in the summer of 1994-1995) to assist in the interpretation of the results and to gauge the extent of recovery of the affected biota.