Consideration of fish introductions into the Sepik River, Papua New Guinea

. The fish fauna of the Sepik River system, Papua New Guinea is described. The fish species diversity in this large river is low, even by comparison to other overs in the south of the island. There are particular biological constraints to increasing the yield of the fishery based on native fish stocks. The yield of the Sepik River fishery is low by comparison to rivers in other zoogeographie regions. People in the Sepik also suffer from protein malnourishment. The introduction of appropriate fish species would significantly improve the stocks upon which the fishery is based. The economic cost of stocking is not an issue. Yield estimates suggest that the long‐term benefits of improved stocks could be considerable. The indigenous freshwater fish fauna is unique and arguments against stocking relate to the conservation of that fauna and the existing fisheries. Alternatives to stocking are discussed. If stocking does not occur then a permanently disadvantaged fishery must be accepted. Decisions rest with the government and will be based on further research and consideration. Considerations must relate to the particular inland fisheries development problems in the country. The approach being taken is to appraise fish introductions properly before they occur. A cautious approach is recommended and suggestions about particular species that might be suitable for introduction are premature at present.