Seabird mortality in the Japanese tuna longline fishery around Australia, 1988–1995

Gales, Rosemary; Reid, Tim

doi:10.1016/s0006-3207(98)00011-1

Cited by 143 publications

(118 citation statements)

References 18 publications

Supporting

Mentioning

108

Contrasting

Unclassified

Order By: Relevance

“…As central-place foragers, both males and females should return to the nest for incubation or chick rearing, thus both sexes are obliged to occur around the colony. Results differed in other studies with these species (Table 3) on mortality in fisheries within the foraging range of breeding birds, such as in New Zealand and Australia (Bartle 1990;Murray et al 1993;Gales et al 1998), suggesting that the larger size of males or higher male aggressiveness do not play an important role. The most detailed study (Gales et al 1998) tested for ASR in different areas and seasons and found that some species are skewed during one season or in one area but show even ASR in other areas or seasons.…”

Section: Discussioncontrasting

confidence: 71%

See 1 more Smart Citation

Sex-biased incidental mortality of albatrosses and petrels in longline fisheries: differential distributions at sea or differential access to baits mediated by sexual size dimorphism?

2010

View full text Add to dashboard Cite

. Sex-biased incidental mortality of albatrosses and petrels in longline fisheries: differential distributions at sea or differential access to baits mediated by sexual size dimorphism?. Journal für Ornithologie = Journal of Ornithology, Springer Verlag, 2010, 152 (2) AbstractSkewed Adult Sex Ratio (ASR) has been proposed as a common pattern in birds, frequently biased towards males and with larger biases in globally threatened species. In albatrosses and petrels, it has been suggested that differential mortality of one gender in fisheries is caused either by sexual size dimorphism giving males a competitive advantage, which allows more access of the larger sex (i.e. males) to discards and/or baits, or to at sea segregation of sexes.Here we tested these hypotheses by determining ASRs in albatrosses and petrels trapped at sea when attending longline fishing vessels for discards in the Southwestern Atlantic Ocean, and searched in the literature for patterns in ASR in albatrosses and petrels killed by fisheries in this area and elsewhere. We show that skewed ASR is common in albatrosses and petrels in the community attending vessels for discards, confirming results found for birds in general.There was no correlation between skewed ASR and conservation status, or between ASR and sexual size dimorphism. Our review of the sex of birds incidentally killed in fisheries found skewed ASR toward males, females or parity to be equally reported. Thus, sexual dimorphism in size does not explain skewed ASR in the community we sampled or in incidental captures in fisheries in the review. Differential at sea distribution of sexes appears to be a better explanation of the patterns found in the community sampled at sea as well as skewed ASR in seabird fatalities, particularly distant from breeding areas. KeywordsAdult sex ratio; seabirds; incidental capture; longline fishery, sexual

show abstract

Section: Discussioncontrasting

confidence: 71%

“…Bartle 1990, Roma 2009), variable asymmetry towards either gender, or not differing from parity (e.g. Gales et al 1998;Gandini and Frere 2006). Reasons for biased sex ratios in fisheries fatalities have been suggested, but not specifically tested.…”

Section: Introductionmentioning

confidence: 99%

Sex-biased incidental mortality of albatrosses and petrels in longline fisheries: differential distributions at sea or differential access to baits mediated by sexual size dimorphism?

2010

View full text Add to dashboard Cite

show abstract

“…Bycatch rates (birds / 1,000 hooks) in tuna longline fisheries reach 0.360 in Southern African waters SEABIRD BYCATCH BY MEDITERRANEAN DRIFTING LONGLINE 67 and 0.379 in Australasian waters (Ryan and BoixHinzen, 1998). Japanese tuna longline fisheries around Australia have caught 0.15 birds / thousand hooks (Gales et al, 1998). Bottom longlining in the Northeast Atlantic reaches bycatch rates of 1.05 birds / 1,000 hooks (Tasker et al, 2000).…”

Section: Discussionmentioning

confidence: 99%

The incidental capture of seabirds by Spanish drifting longline fisheries in the western Mediterranean Sea

Valeiras¹,

Camiñas²

2003

Sci. Mar.

View full text Add to dashboard Cite

SUMMARY: The western Mediterranean Sea is an important fishing area for the Spanish drifting longline fleet, targeting swordfish (Xiphias gladius), bluefin tuna (Thunnus thynnus) and albacore (T. alalunga). Some seabird species can be captured incidentally as bycatch marine fauna. From July 1999 to August 2000 information on 554 surface longline sets was collected by onboard observers of the Spanish Oceanographic Institute (IEO) on 18 longline fishing boats working within the Spanish Mediterranean fishing area. Eleven yellow-legged gulls (Larus cachinnans), 9 Cory's shearwaters (Calonectris diomedea) and 1 Northern gannet (Morus bassanus) were captured incidentally. Bycatch rates ranged from 0.002 to 0.023 birds/1000 hooks.

show abstract

“…Our study shows that there are new concerns for the conservation of seabirds at sea, notably in the case of immature individuals. These birds may actually represent the most challenging category of the population to conserve adequately because of both their extremely large spatial distribution intersecting the highest number of countries' EEZs, and their inexperience in dealing with at-sea threats (Gales et al 1998, Weimerskirch et al 2006, Trebilco et al 2008. Conversely, movement metrics were never significantly different between sexes, which may limit the complexity of conservation measures for this species.…”

Section: Variability In Distribution and Movementsmentioning

confidence: 98%

Stage-dependent distribution of the Critically Endangered Amsterdam albatross in relation to Economic Exclusive Zones

Thiebot¹,

Delord²,

Marteau³

et al. 2014

Endang. Species. Res.

View full text Add to dashboard Cite

Long-lived animals typically exhibit several stages throughout their life cycle during which their distribution may vary substantially, which may challenge the relevance of protection measures. Here we surveyed individual movements of the Critically Endangered Amsterdam albatross from Amsterdam Island, southern Indian Ocean, throughout its life cycle. Our goal was to identify, from the areas visited by the albatrosses, which coastal states share responsibility in regulating industrial fishing in their Exclusive Economic Zones (EEZs) in order to promote the preservation of this species. Using stage-relevant tracking techniques (satellite tags, GPS and GLS loggers), we surveyed 361 at-sea trips by 93 individuals over 9 yr, covering incubation, brooding, chick-rearing, sabbatical, failed-breeding, juvenile and immature stages. Our data show that Amsterdam albatrosses exhibit a wide and variable foraging radius (from 326 ± 193 km during brooding to 5519 ± 766 km for immatures) and at-sea distribution across stages, putting them beyond the French EEZ of Amsterdam Island for all or part of the trips surveyed in each stage, and even outside the Indian Ocean when breeding. In all, the breeding versus non-breeding albatrosses visited the EEZs of 1 to 3 versus 3 to 4 countries, respectively. Only breeders visited the EEZs of Madagascar and Mauritius, while only non-breeders visited the EEZs of Australia, South Africa and Namibia. This study stresses the relevance to conservation of obtaining synoptic information on the distribution of threatened species, especially regarding the breeding versus nonbreeding categories of populations.

show abstract

Seabird mortality in the Japanese tuna longline fishery around Australia, 1988–1995

Cited by 143 publications

References 18 publications

Sex-biased incidental mortality of albatrosses and petrels in longline fisheries: differential distributions at sea or differential access to baits mediated by sexual size dimorphism?

Sex-biased incidental mortality of albatrosses and petrels in longline fisheries: differential distributions at sea or differential access to baits mediated by sexual size dimorphism?

The incidental capture of seabirds by Spanish drifting longline fisheries in the western Mediterranean Sea

Stage-dependent distribution of the Critically Endangered Amsterdam albatross in relation to Economic Exclusive Zones

Contact Info

Product

Resources

About