THE FATE OF CETACEAN CARCASSES IN THE DEEP-SEA - OBSERVATIONS ON CONSUMPTION RATES AND SUCCESSION OF SCAVENGING SPECIES IN THE ABYSSAL NORTHEAST ATLANTIC-OCEAN

The fate of cetacean carcasses in the deep sea was investigated using autonomous deep-sea lander vehicles incorporating time-lapse camera sy stems, fish and amphipod traps. Three lander deployments placed cetace an carcasses at depths of 4000-4800 m in the north-east Atlantic for p eriods of 36 h, 152 h and 276 h before being recovered. The photograph ic sequences revealed that carcasses were rapidly consumed by fish and invertebrate scavengers with removal rates ranging from 0.05-0.4 kgh( -1). In the longest experiment the carcass was skeletonized within fiv e days. In each deployment, approximately an hour after emplacement, t he grenadier Coryphaenoides (Nematonurus) armatus and large numbers of lysianassid amphipods had arrived at the food-fall. The initially hig h numbers of grenadiers declined once the majority of the bait had bee n consumed and a variety of other fish and invertebrates were then obs erved, some taking up residence at the site. None of the fish species appeared to consume the carcass directly, but preyed upon amphipods in stead. Funnel traps recovered with the carcass indicated a succession in the species composition of amphipods, with the specialist necrophag es such as Paralicella spp. being replaced by more generalist feeders of the Orchomene species complex.