The essential elements to sustain fisheries

Healthy marine ecosystems are vital for sustaining fisheries, poverty reduction, food security, and economic development worldwide. However failure to understand ecosystem dynamics – and particularly how they change under anthropogenic impacts – underpins major ecosystem shifts across the globe. Without robust and careful governance in place, levels of stress on ecosystems and fisheries are likely to have a continuous negative impact on biodiversity and fish stock abundance. Fish stocks are subject to a plethora of human-related impacts such as overfishing, habitat destruction, pollutants, and environmental change. Without appropriate knowledge and understanding of how to sustainably manage fisheries and the ecosystems that support them, the risk of ecological failure, fishery collapse, and ultimately social collapse is large. Despite increased efforts in fisheries research and management, improvements are still needed to restore the over-exploited fisheries and ensure sustainability of all fisheries. The foundation of this PhD thesis is to investigate how human impacts influence biodiversity and fish stock abundance, and the management tools that can be used to sustain fisheries. This project takes a holistic approach to the risk of overfishing and fisheries collapse, and what is needed to make them sustainable based on key biological, environmental, social, economic, industry, governance, and management variables and associated criteria effecting stock abundance. Considering the complex socio-ecological interactions that affect the sustainability of marine ecosystems and fisheries, this research investigates what sources might facilitate sustainability or trigger shifts towards overfishing or even collapse. To date this kind of holistic approach has been lacking, and this thesis is intended as one step towards redressing that gap. To better understand how to sustain fisheries a mixed method approach was used, by combining a meta-analysis of 21 fisheries, a qualitative survey of 188 fisheries experts from 34 nations, and a case-study of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). CCAMLR was used as a case-study as the ecosystems, and fisheries, within the convention area are perceived to be well-managed. There is a consistent emergent picture across the three analyses on how to sustain fisheries. The meta-analysis showed that the 14 sustainable fisheries identified were associated with sound biological knowledge, had a large range of management tools in place, and included some element of industry control such as a paid quota system. The survey of fisheries experts confirmed these findings as well as highlighting that there are a range of management tools that have proven efficient to sustain fisheries worldwide, if implemented and applied properly and conscientiously. Further, views of the fisheries experts (representing 34 nations) are consistent with the findings of the case study of CCAMLR, governed by 25 nations. Since its beginning in 1982, CCAMLR has managed to avoid collapse of the fisheries under its remit, has overseen substantial stock recovery in areas where degradation had occurred in the past and has seen through a number of continuously up-dated conservation measures with the aim of providing for marine conservation and fisheries sustainability. These activities match the measures in place for the 14 sustainable fisheries in the meta-analysis and align well with the experts’ view on how to sustain fisheries. A common thread through the three analyses comprising the thesis is that abundant scientific knowledge and establishment of management programs is insufficient to ensure fishery sustainability, but that political will must match the level of management challenges to ensure sustainable marine ecosystems long term