Economic performance, technical efficiency and fishers’ perceptions of factors affecting fishing activities. A study of a Vietnamese purse seine fleet

The focus of this thesis is on the economic performance and technical efficiency of a Vietnamese fishing fleet by the use of data envelopment analysis (DEA). The double bootstrap method has been used to overcome some of the limitations of DEA. In addition, the dissertation evaluates fishers’ perceptions of negative events affecting the fishing activities. The first of three papers presents the investigated fleet and the economic performance in 2016 under open access conditions. Fixed and variable costs, and revenue have been used for estimating the technical efficiency. By adopting double bootstrap DEA under the hypothesis of variable returns to scale, the average technical efficiency of the fleet is found to be relatively high. Nevertheless, the DEA calculations showed that the current catch level could be obtained by a fishing effort 24–35% lower than the actual vessel activity. Vessel size and fishing experience are all factors affecting the technical efficiency. The second paper measures and compares the technical efficiency using physical vs. economic measures. The study focuses on the same 52 Nha Trang purse seiners as in the first paper. Adopting the double bootstrap DEA method, the findings show that economic measures give a lower level of technical efficiency than that which is obtained by physical measures. However, there is significant difference in the technical efficiency between these two measures. The skipper’s experience and interest payment significantly affects the physically based technical efficiency at the 5% level. This study concludes that physical variables, which are often more accessible, are capable of capturing essential economic differences between vessels. The third paper studies the same purse seine fishers’ perceptions of how environmental and socio-economic factors influence their life and fishing activities. The findings are that storms/cyclones, severe floods, heavy rains, high temperature, big waves and bad weather reduce fish density, and the poor availability of capital, health conditions and crew access all negatively affect fishing activities. The fishers’ perceptions of the increased temperature and declining fish stocks over time are in line with available data, whereas their perceptions of the frequencies of storms, floods and heavy rains differ from the observations. Despite increasing frequencies of storms and precipitation not actually observed, the fishers perceive such factors as creating problems for their current fishing activities. Almost all the fishers in the sample expected the frequency and severity of rainfalls and the average temperature to increase in the future, while fish stock availability will decline. However, climate change is not expected to be among the most important negative factors in the future. Cost of fishing, health conditions, efficient fishing gear and boats, as well as the resource situation, represent important factors causing greater concern among fishers regarding future fishing activities