The role of marine protected areas in enhancing biodiversity and ocean sustainability.

Human activities are greatly affecting the marine environment, reducing biodiversity and diminishing the fauna and flora at an unsustainable rate. Marine protected areas (MPAs) are a tool to help reduce the effects of these harmful impacts. Several aspects of an MPA affect its success in achieving its ecological goals. For example a previous study suggested that age, size, no-take zone (NTZ) status, isolation and enforcement were the main factors contributing to the ecological success of the MPA. It is also known that tourism pressure can contribute to the ecological degradation of an MPA. These aspects vary widely between MPAs. In this study I will examine the effectiveness of a range of MPAs across the world, and predict their ecological effectiveness based on the aspects above. I use a Bayesian belief network to predict the likely ecological success (i.e. enhancing stock sizes or increasing biodiversity) of 27 MPAs, modelled both in the absence and presence of potentially conflicting socio-economic and legal pressures. This study suggests that isolation is the most important factor affecting an MPA’s ecological success rate, while the incorporation of conflicting pressures; i.e. the location’s effect on tourism, made little difference to the predicted ecological success. Enforcement influences many other success factors, which is why identifying and implementing policies that will support and increased enforcement are so important. At present there are ongoing negotiations for new legal treaties to allow more large isolated MPAs in the high seas. However, establishing environmental management protocols for MPAs based on existing concepts such as ISO 14001 would ensure minimal fishing and tourist damage, as well as ensuring the establishment of long- term, well enforced MPAs