Tuna fishing is a vital export industry in Solomon Islands, Kiribati and Fiji, providing a major source of employment and foreign currency earnings, and, to a much lesser extent, food for local consumption. (In 1988 some 35 000 tonnes of tuna were exported from Solomon Islands, earning more than A$40m in export revenue.) The low-cost pole-and-line method of tuna fishing - the one most often used - is dependent on an adequate and regular supply of suitable baitfish, which are thrown live into the sea to attract tuna schools within fishing range of the boat. The viability and development of pole-and-line fleets depends on an understanding of the fundamentally important baitfish resource. Comprehensive biological data need to be collected and analysed in order to manage and protect the resource, which may be threatened by overfishing.
The baitfish resource of Solomon Islands, Maldives and (latterly) Kiribati was the subject of an earlier ACIAR-funded study (8543) from 1986-89, involving the CSIRO Division of Fisheries. The expertise of the Division in fisheries research permitted the establishment of a sound base of biological information on baitfish, which has already had wide applicability to fishery management in the South Pacific, and indicated priority areas for further research. The project found that in Solomon Islands the impact of baitfish fishing on the highly valued artisanal reef fishery was minimal, with the result that restrictions on baitfish fishing were not required there.
This replacement project will build on the first to provide more scientific data for the rational management and conservation of the baitfish resource, both for the traditional owners, and in order to allow continuing maintenance of supplies for commercial tuna fisheries. It will:
. determine the effects of increasing baitfish fishing effort on reef fisheries prior to increases in the pole-and-line fleet in Fiji;
. continue to collect, analyse and interpret biological data;
. use otolith ageing and length-frequency data of major baitfish species to generate parameters to model the fisheries and compare sites with different levels of fishing;
. examine diet and prey selectivity of the main baitfish species to determine influence of food on distribution and abundance of baitfish;
. determine critical recruitment periods for the main species and the major factors influencing reproduction;
. monitor commercial fishery by-catch and provide estimates of mortality of critical species due to incidental collection during baitfish fishing, to assess whether this mortality is significant; and
. synthesise current knowledge of baitfish throughout the Indo-Pacific in order to make practical management recommendations.
Much of the sampling will be done by the developing-country partners in collaboration with CSIRO, while detailed analyses will be performed at the CSIRO Division of Fisheries laboratories in Australia in conjunction with scientists from the partner countries. Staff from the developing countries will also be trained in research procedures at the CSIRO laboratories.
Project benefits include further planned development of the pole-and-line tuna and baitfish industries based on a scientifically managed baitfish industry. The baitfish research is expected to enable the existing cost structure of baitfish collection to remain at current levels, for example by identifying alternative and new stocks of baitfish and improving the efficiency of baitfish collection, while without research it is likely that baitfish costs would increase. The Solomon Islands and Fiji Governments will also be better placed to establish equitable licence fees for baitfish leases, which will in turn directly benefit the traditional owners of the baitfish grounds. In addition, fisheries staff of the developing-country partners will receive training in fundamental biological and fisheries techniques.
Benefits to Australia lie mainly in the development of additional expertise and a broader understanding of pelagic and reef-associated fish communities similar to those found in northern Australian waters.