Humans and the Southern Elephant Seal Mirounga leonina

Abstract

Southern elephant seal (Mirounga leonina) populations appear remarkably unaffected by interactions with humans. They are very tolerant of close human presence whilst they are ashore for pupping, mating and moulting. Their behaviour in close proximity to helicopter operations suggests disturbance of moulting male M. leonina is minimal. There is no evidence that M. leonina have been affected by persistent organic pollutants; and few M. leonina have been reported as having been injured or killed by interactions with fishery gear. The number of prey species common to their diet and commercial fisheries in the Southern Ocean are few; but one commercial squid species, Martialia hyadesi, accounted for as much as 94% of the biomass consumed by M. leonina. Two harvested commercial squid species (Mar. hyadesi and Todarodes filippovae) were found in the stomachs of M. leonina; and some other squid species (Alluroteuthis antarcticus, Brachioteuthis spp., Gonatus antarcticus, Histeoteuthis spp., Kondokovia longimana, Moroteuthis ingens, Mor. knipovitchi, Pholidoteuthis boschmani and Psychroteuthis glacialis) have potential as commercial catch too. There is cause for concern if a future directed fishery for any of these species escalates or the by-catch of Mar. hyadesi and T. filippovae in the Illex and Nototodarus fisheries increase. There is also concern if fin-fish fisheries expand and take more of those species already taken by both M. leonina and fisheries. These species are benthic (Notothenia squamifrons), benthopelagic (Dissostichus eleginoides and Champsocephalus gunnari) and, perhaps most importantly, the pelagic myctophid species (e.g., Electrona carlsbergi).