Research on baitfish biology in the Solomon Islands, Maldives and Papua New Guinea for the Tuna industry

• Ministry of Fisheries, Maldives
• Ministry of Environment and Natural Resources Development, Kiribati
• Ministry of Agriculture and Fisheries, Solomon Islands
• Department of Primary Industry, Papua New Guinea

Tuna fishing is a vital source of food, employment and export earning in both Solomon Islands and Maldives. Most of the tuna is caught using the traditional pole-and-line method, a technique that relies on baitfish - small fish which are thrown live into the sea to attract tuna schools within fishing range of the boat.

The long-term viability of pole-and-line fleets in both countries depends upon the assured availability of baitfish. Sampling of baitfish commenced in Solomon Islands in 1982, but a more coordinated effort is needed to understand baitfish biology and to determine the impact of baitfish extraction on the reef fish populations.

Tuna fishing in the Maldives involves a large proportion of the population. Tuna consumption per capita is the highest in the world, and tuna meat is the main source of protein. The country also wishes to boost its tuna exports, and a key component in this effort is the baitfish supply. There is evidence of local overfishing of baitfish and habitat destruction through coral mining. The biological status of the baitfish stocks needs to be established before an effective management plan can be devised. Traditional fishing practices also need examining.

The main objective of this project is to collect and analyse biological information on the important baitfish species in both Solomon Islands and the Maldives. These data will enable better management and conservation of the resource for both the traditional owners and the commercial tuna fisheries.

Scientists will make a taxonomic evaluation of the baitfish population, and analyse species composition of baitfish catches throughout the year, recording weight and numbers of each species contributing to the total catch.

They will determine the population dynamics of the major baitfish species at several sites in Solomon Islands and Maldives, and study the recruitment patterns of the baitfish species at each site. In addition they will establish the importance of baitfish in the food chain leading to the reef fish.

Other factors that the scientists will examine include: diet and feeding habits, and the influence of zooplankton species composition and distribution on the diets and abundance of baitfish; physio-chemical factors such as temperature, turbidity and currents. They will seek to improve technical and management aspects at each site, and determine the impact of existing fishing intensities on baitfish populations. Data collected will enable assessment and prediction of changes in populations resulting from varying degrees of exploitation.

Benefits from the projects are expected to flow on to other countries of the Pacific and Indian Oceans.

This baitfish research fits into the research framework currently in progress at the CSIRO Division of Fisheries Research. Australia, Solomon Islands and Maldives share the same Indo-Pacific marine fish fauna, and the project will thus have widespread scientific relevance on top of the benefits to the tuna fishing industry.