White-Capped Mollymawk

Forest and Bird, Volume 21, Issue 4, 1 November 1990, Page 27

White-Capped Mollymawk

The white-capped mollymawk nests only in two areas. In 1972-73, the Auckland Islands were estimated to have 64,000 pairs. A further 3,500 pairs nest on islands around Tasmania. The population is therefore made up of about 135,000 breeding adults with a further estimated 135,000 non-breeders. Immature birds may not breed until about their eighth year. The species’ biology in New Zealand has never been studied. More than 20,000 white-capped mollymawks are estimated to die in the bluefin tuna longline fishery and the Auckland Island squid fishery each year. This represents a staggering eight percent annual mortality in these fisheries alone. Worst still, all known fisheries deaths are of adult birds. Albatrosses are very long lived, up to 50 years, and pair for life. Both sexes incubate eggs and rear young and one adult cannot do this on its own. Thousands of chicks will have starved as a result of the high adult fishery kill and

thousands more eggs will have failed to hatch. Breeding colony counts from the Auckland Islands are hopelessly inadequate. The 1972-73 count is the only one ever done. The population could have been decimated in the last 20 years. A survey of Disappointment Island, where 90 percent of the world’s population breeds, is desperately needed.

Wandering Albatross

The magnificent wandering albatross is well known for its huge size with a wing span of 3.4m. Worldwide declines of this species first alerted the world to the scale of the longline seabird by-catch problem. At the Crozet and Kerguelen Islands in the South Indian Ocean a dramatic decline has occurred during the 1970s and 80s, with most colonies reduced by half. At South Georgia and Gough Islands in the South Atlantic and at Macquarie Island, south of Australia, similar declines are reported. A bird marked on South Georgia was drowned on a longline off New Zealand in 1980. Figures indicate that 10,000 wanderers die in the bluefin tuna longline fishery annually. This represents about 10 percent of the world population. New Zealand catches are mainly adult birds. Wanderers are also killed by trawlers, are shot or trapped and eaten by fishers. New Zealand's sub-antarctic islands are the

stronghold of the species. In 1972/73, Adams Island in the Auckland group had about 7,000 pairs — by far the largest island population. The only survey of Adams Island since then in 1989, indicates a possible decline of up to two-thirds. This tallies with at-sea counts in areas such as northern New Zealand waters where tuna longlining has been carried out. From the 1950s to the mid-70s, up to 20 wanderers could be seen following boats; now it is rare to see five at one time. Transects by colleagues and myself between Auckland and the Kermadec Islands from 1988-89 reveal that only 10-20 percent of the number of birds seen in the mid-1960s now occur in our northern waters.