Publications

Threat Abatement Plan for the Incidental Catch (or by-catch) of Seabirds During Oceanic Longline Fishing Operations

Prepared by
Biodiversity Group Environment Australia in consultation with the Threat Abatement Team
Environment Australia, 1998
ISBN 0 642 21420 4

5. Defining the Key Threatening Process (continued)

5.4 Seabird species recorded as by-catch taken during oceanic longline fishing operations in the AFZ

Fourteen species of seabirds were identified as being affected by the key threatening process when it was listed in July 1995. Since the listing, a further seven species have been recorded as by-catch in Australian or Japanese longline fisheries operating in the AFZ.

The taxonomy of the albatrosses has also been revised since the listing of the key threatening process, following genetic and morphometric studies by Robertson and Nunn (1997). This review has resulted in an increase in the number of albatross species from 14 species to 24 full species.

The species known to be affected by pelagic longline fishing in the AFZ are listed in tables 2 and 3. These species are typically large seabirds which naturally feed on fish and squid found on or close to the surface. They all exhibit behaviours which make them susceptible to being caught on longlines, such as diving for baits. They have learned to follow vessels and forage on discards. They are aggressive feeders, and in most cases travel large distances seeking food. The worst affected group are the albatrosses and petrels because of their limited population sizes and low reproductive rates. Gales and Brothers (1995) reported that 75% of the birds killed on longlines and retained for identification were albatrosses. It is likely that other seabirds were caught but not retained.

There is limited or no data available on bird species taken as by-catch in demersal longline fisheries within the AFZ.

5.5 Spatial Distribution of Affected Species

The seabird species affected by the key threatening process are principally found in waters south of 25°S (Fraser Island on the east coast and Shark Bay on the west coast) and more commonly below 30°S. Tables 2 and 3 summarises the distribution of each species based on distribution data presented in Marchant and Higgins (1990).

Other seabird species which are found in northern areas where longline fishing operations occur are not caught as by-catch because they are not attracted to the fishing vessels or the longline baits (Brothers pers. comm.).

5.6 Conservation Status of Affected Species

The seabird species caught on longlines are highly varied in conservation status. They include endangered species such as the northern royal albatross Diomedea sanfordi and prolific species such as the short-tailed shearwater Puffinus tenuirostris. The Endangered Species Protection Act 1992 requires this Plan to consider not only endangered and vulnerable seabird species but other seabird species which could become endangered or vulnerable as a result of the key threatening process.

This Plan is closely linked to recovery plans for the threatened seabirds which are caught on longlines. The Threat Abatement Plan relies on these recovery plans to collect specific data on population trends in the breeding populations of those threatened species found breeding in Australia.

5.7 Longline Methods Covered by this Plan

This Plan considers all longline operations and makes specific prescriptions where required for particular fishery types, target species, methods, areas and seasons in order to minimise by-catch and mortality of seabirds.

This Plan does not cover by-catch of seabirds in State waters in Australia inside the 3 nautical mile state boundary. There are a number of Joint Authority arrangements that exist between the Commonwealth and the Northern Territory, Western Australia, New South Wales and Queensland Governments for fisheries. These arrangements mean that some fisheries, particularly shark fisheries which use longline techniques, are managed under State/Territory law out to 200nm. Given that the ESP Act applies to Commonwealth waters (which are all waters beyond 3nm), where fisheries are managed by State agencies in Commonwealth waters, actions prescribed under the Threat Abatement Plan would need to be taken into consideration.

Data derived from Marchant and Higgins (1990) and Gales (in press)
Incidence information from Gales and Brothers (1995) and unpublished data held by the Parks and Wildlife Service, Tasmania.