CONCLUSION
Our analysis shows that, notwithstanding Namibia’s efforts to rebuild its most valuable fishery, the resource remains depleted. At the same time, lack of understanding of hake behavior on the one side, and the social and ecological factors affecting fishing behavior on the other, lead to inaccuracies in the current assessment of resource abundance. Our research shows that there are many points of convergence—i.e., between the experiencebased knowledge of fishers and the quantitative knowledge that underpins fisheries science and management in Namibia, particularly recent logbook analyses—relevant for improved stock assessments and management.
Systematic collection of fishers’ information is important. When fishers’ information matches scientific information, uncertainty in the assessment is reduced and fishers’ confidence in the assessment is strengthened. When the information diverges, further investigation of both types of information is required, which will ultimately strengthen the knowledge base (Neis et al. 1999b). However, we have also shown that there are details that are not being captured either in the logbook data or in the surveys. These details—such as information on stock structure, the spatial distribution of different stock components, and fishing efficiency —are potentially important for making accurate assessments of stocks and for undertaking improved management. Erosion of subcomponents leads to reduced intra-specific diversity. Thus, good knowledge of stock structure is important for maximizing the resilience of the stock. Moreover, disregarding efficiency increase and fishing strategy leads to inflated indices of abundance based on CPUE data.
Qualitative information from in-depth interviews and jointly designed research projects has the potential to improve the accuracy of Namibian hake stock assessment. Thus, engaging fishers more directly in gathering and interpreting the data used in stock assessments could help strengthen this knowledge. However, close collaboration between scientists and fishers contains potential risks for fishers and fishing companies because improved accuracy and inclusion of efficiency considerations may result in decreased quotas. Equally, in-depth knowledge of the information underpinning the assessment process and associated uncertainties may lead to directed efforts by the industry to manipulate information to avoid quota reductions. Clearly, this is a complex problem and there is no easy solution. However, the rebuilding of the Namibian hake stocks is in the interest of all who have a long-term stake in the fishery, including Namibian society as a whole.
The rebuilding of the hake resource is impeded not simply by limitations in current fisheries science but also by total allowable catches that are set well above the scientific recommendation (Fig. 1, Paterson et al. 2013). This dilemma is caused by economic and political interests that benefit from any weakness in the scientific underpinning of pleas for conservative catch rates (Paterson et al. 2013). Stronger stock assessment science is a necessary but not sufficient requirement for rebuilding Namibian hake stocks and for sustainable fisheries. The other requirements are for reduced total allowable catches and, more importantly, reduced mortality that together will permit stock recovery and restore biodiversity, where possible, to a level of greater resilience. Given that landings have not improved despite increased efficiency, it seems clear that the rebuilding of the Namibian hake stocks will not be achieved through “business as usual”.