Pubblicazione scientifica

Evidence of separate subgroups of juvenile southern bluefin tuna

FILONE TECNOLOGICO	TEMA
economia circolare e sostenibilità
produzione e cattura
produzione e raccolta

RIASSUNTO

Abstract

Archival tagging studies of southern bluefin tuna ( SBT, Thunnus maccoyii) have revealed that juveniles residing in the Great Australian Bight ( GAB) over the austral summer undertake seasonal cyclic migrations to the southeast Indian Ocean and the Tasman Sea during winter. However, there remains disagreement about the extent of mixing between juvenile SBT regularly caught by longline fleets south of Africa and those observed in the GAB. Some researchers have argued that archival tag recoveries indicate most juveniles reside in the GAB over the austral summer. Others have suggested that recoveries of conventional and archival tags are better explained by a juvenile population consisting of separate groups on the eastern and western sides of the Indian Ocean with limited intermixing. We present analyses of catch and tag recovery data and re‐examine archival tagging studies. The evidence provided strongly favors the hypothesis of separate juvenile subgroups, or contingents, with limited intermixing. We draw some tentative conclusions about the nature of the putative contingents and discuss some implications of these findings for the interpretation of existing datasets and future research priorities. We also provide the first evidence that the migration choices of juveniles that summer in the GAB are influenced by fidelity to winter feeding grounds and suggest this helps explain the collapse of the surface fishery off New South Wales in the 1980s.

DATA

Data di pubblicazione: 02/11/2017

AUTORI

CHAMBERS MARK S
SIDHU LEESA A
ONEILL BEN
SIBANDA NOKUTHABA

ENTE DI AFFERENZA

SCHOOL OF PHYSICAL ENVIRONMENTAL & MATHEMATICAL SCIENCES UNIV NEW SOUTH WALES CANBERRA AT AUSTRALIAN DEFENCE FORCE ACAD CANBERRA BC AUSTRALIA
SCHOOL OF MATHEMATICS & STATISTICS VICTORIA UNIV WELLINGTON WELLINGTON NEW ZEALAND

RIVISTA

Ecology and Evolution, 7(22), 9818-9844

IMPACT FACTOR

2,540

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