A bioeconomic analysis of tuna purse seining in the Pacific Islands region

• Forum Fisheries Agency, Solomon Islands
• South Pacific Commission, New Caledonia

Tuna fishing in the western Pacific yields the world's largest catches. Catch sizes have increased rapidly over the past decade with over 1.5 million tonnes caught every year since 1991. Purse seine fishing is largely responsible for this.

Evidence suggests the increased use of purse seine fishing by vessels from outside the Pacific Island region is resulting in reduced catches per unit effort for local longline and pole-and-line fisheries. While there is no evidence of over-fishing of skipjack stocks, there is some concern over purse seining on yellowfin stocks.

Japan, USA, TAIWAN and Korea conduct most of the tuna fishing in the region, with the exception of the Solomon Islands. Access agreements to these fishing grounds are the main source of economic return to Pacific Island Nations from their tuna resources. Countries who are Parties to the Nauru Agreement license most of the outside fishing vessels.

The aim of this project is to produce three models as tools to help maximise returns to Pacific Island nations from their tuna resources in a sustainable manner. It aims to provide information to these nations on optimal levels of fishing effort allocated to the three fishing methods and to particular areas in the region.

There are three main methods of tuna fishing used in the region. Purse seine targets two types of tuna, skipjack and yellowfin, pole-and-line targets skipjack, and longline targets yellowfin and bigeye.

Purse Seine/Exclusive Economic Zone Model will deal with the optimal level and distribution of purse seine fisheries within an Exclusive Economic Zone or Fishing Zone (Solomon Islands). The model will take into account: the interaction of purse seine fisheries with pole-and-line fisheries; the movements of skipjack tuna stocks; the impact on adjacent Exclusive Economic Zones and; the use of Fish Aggregation Devices (devices which cause the fish to congregate in one area).

Purse Seine/Longline Model will deal with the optimal level of purse seine fishing in the region taking into account the interaction between the purse seine and longline fisheries.

The first two models will integrate the knowledge of the economic side of tuna operations coordinated by Forum Fisheries Agency, with the biological research on regional stocks obtained by the South Pacific Commission.

The third model will determine the relationship between tuna production by the various fishing methods and the price obtained at major markets. Information from this model will feed into the other two models.