Inter-Research > ESR > v5 > n2-3 > p117-127  
Endangered Species Research

via Mailchimp

ESR 5:117-127 (2008)  -  DOI:

Albatross overlap with fisheries in the Benguela Upwelling System: implications for conservation and management

Samantha L. Petersen1,2,*, Richard A. Phillips3, Peter G. Ryan2, Les G. Underhill4

1WWF Responsible Fisheries Programme, PO Box 50035, Waterfront, Cape Town 8001, South Africa
2DST/NRF Centre of Excellence at the Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch 7701, South Africa
3British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
4Animal Demography Unit, Department of Zoology, University of Cape Town, Rondebosch 7701, South Africa

ABSTRACT: Trawl activity on the continental shelf break off South Africa provides large quantities of food in the form of discards for a range of species, including non-breeding black-browed albatrosses Thalassarche melanophrys and white-capped albatrosses T. steadi. As large numbers of both species are killed in collisions with trawl warp cables, mitigation measures have been introduced that include limitation of discards, yet little is known about the consequences of reduced food supply for scavenging birds. We tracked adult and immature albatrosses in the southern Benguela in the austral winters of 2005 and 2006 and examined their distribution in relation to fisheries, bathymetry and remotely sensed oceanography. Kernel analysis revealed that white-capped albatrosses spent most (85.0%) of their time on the southern African trawl grounds, whereas black-browed albatrosses spent only 39.2% of their time in these areas, and the remainder on return oceanic foraging trips, typically of 8.4 d duration and 2540 km (max. 5320 km) in length. While foraging in South African waters, the presence of trawlers was a strong predictor of albatross distribution. While on oceanic foraging trips, black-browed albatrosses moved predictably along the margins of eddies, typically areas of enhanced productivity and high prey concentrations. This study presents evidence that black-browed albatrosses forage to a much greater extent on natural prey than do white-capped albatrosses. Therefore, given the high incidence of albatross collisions with trawl cables, the benefit of a management decision to limit discarding as a mitigation measure is likely to outweigh the disadvantage of reduced food.

KEY WORDS: Seabird movements · Albatrosses · Satellite tracking · Longline · Trawl · Fisheries

Full text in pdf format 
Cite this article as: Petersen SL, Phillips RA, Ryan PG, Underhill LG (2008) Albatross overlap with fisheries in the Benguela Upwelling System: implications for conservation and management. Endang Species Res 5:117-127.

Export citation
RSS - Facebook - - linkedIn