The South Pacific Albacore Fishery: a Summary of the Status of the Stock and Fishery Management Issues of Relevance to Pacific Island Countries and Territories

The purpose of this report is to provide a summary of recent studies on South Pacific albacore and highlight the key issues for PICTs to consider in the management of their domestic longline fisheries. The current (2005) stock assessment for South Pacific albacore concluded that there are no sustainability concerns regarding the overall stock and substantially higher yields could be taken from the fishery. However, this conclusion does not adequately address the management issues faced by the domestic longline fleets in PICTs. The PICT fisheries principally catch larger, older (7–12 years) albacore. These age classes represent a relatively small proportion (about 30%) of the total adult biomass of albacore. Recent levels of fishing effort from all fisheries combined have reduced the level of biomass available to the PICT domestic longline fisheries by approximately 30% compared to unexploited levels. At a regional level, increases in fishing effort in the PICT domestic longline fisheries will result in declines in CPUE due to a decline in exploitable biomass. These impacts are likely to be considerably greater than the impact of large increases in the level of fishing effort by the distant-water fleet in the south-eastern area of the fishery. Catch rates in domestic longline fisheries exhibit strong seasonal trends. For the longline fisheries in Fiji and French Polynesia, these trends appear directly related to seasonal fluctuations in the oceanographic conditions. Seasonal trends in fisheries in adjacent waters are likely to be influenced by similar variations in oceanographic conditions. Inter-annual variation in albacore catch rates is also evident in most of the PICT fisheries. The sustained period of low catch rates that commenced in late 2002 appears to be attributable to inter-annual variation in oceanographic conditions. At a local scale, very high levels of fishing effort appear to be capable of causing localised depletion of albacore tuna. This is principally an issue for domestic longline fleets where fishing effort is concentrated in a relatively small area, largely due to operational constraints of the fleet. The scale of the local depletion effect is likely to vary seasonally and inter-annually as the rate of exchange of fish with adjacent waters varies. Indications from the Fiji longline fishery is that, on average, catch rates may be reduced by about 20% at high levels of fishing effort. Management objectives of the PICT domestic fisheries need to balance levels of fishing effort with the availability of fish to the fishery to ensure economic sustainability of the fleet. Résumé Le présent rapport résume les récentes études sur le germon du Sud et met en relief les principaux points que les États et Territoires insulaires océaniens doivent prendre en considération dans la gestion des flottilles locales de palangriers. L’évaluation des stocks actuels (2005) de germons conclut à la viabilité de l’exploitation de la ressource et confirme que l’activité pourrait offrir des rendements nettement plus élevés. Toutefois, elle n’aborde pas, comme elle le devrait, les problèmes de gestion auxquelles les flottilles locales de palangriers des États et Territoires insulaires océaniens sont confrontées. En effet, les prises sont principalement constituées de germons âgés (7 à 12 ans) et d’assez grande taille. Ces tranches d’âge représentent une proportion relativement faible (environ 30 %) de la biomasse totale des germons adultes. Les activités récentes de toutes les flottilles confondues ont réduit la biomasse disponible dans les États et Territoires insulaires océaniens d’environ 30 % par rapport au niveau intact de la ressource. L’accroissement des activités des flottilles nationales de palangriers, à l’échelle de la région, entraînera des diminutions des prises par unité d’effort (PUE) en raison de la résorption de la biomasse exploitable. Ces impacts seront sans doute beaucoup plus importants que ceux des activités, pourtant bien plus intenses, des flottilles de pêche hauturière dans la partie sud-est de la zone d’activité. Les taux de prise des flottilles nationales de palangriers se caractérisent par des cycles saisonniers très marqués. Aux Îles Fidji et en Polynésie française, ces derniers semblent directement liés aux fluctuations saisonnières des conditions océanographiques. Dans les eaux