Marine protected areas: evaluating policy efficacy and impact in conserving biodiversity

A complex array of policies have been introduced to ameliorate anthropogenic threats and optimise persistence and preservation of marine biodiversity across international, national, and state jurisdictional levels. One policy approach to fulfil international obligations and conserve biodiversity and ecosystem function is the establishment of marine protected areas (MPAs). The act of establishing an MPA, however, does not guarantee its success. Despite the rapid global expansion of MPAs, and the expanse of complex policies for use in their management, many species are still at risk and the condition of ecosystems is in decline. This trend indicates that policy settings are inadequate or the right policies have been prescribed but not effectively implemented. The importance of effective policy implementation to enhance biodiversity outcomes is recognised but rarely has the implementation process been examined.One overarching aim of this thesis is to empirically assess the implementation and subsequent efficacy of marine policy in the management of MPAs. To improve our understanding of the efficacy of marine policy, I investigated: (1) what policies are influential in decision-making in on-ground management of Australian MPAs; (2) how policy intent is applied in practice; and (3) what policy limitations and challenges to practitioners inhibit the successful implementation of policy. This research entailed detailed content analysis of policy instruments, and surveys and interviews with key informants across agencies managing MPAs in Australia, to identify policies implemented in on-ground management and barriers that inhibit these processes. International policies were intended to guide broad goals and most relevant as a framework for decision-making and planning aspects of MPA management. The translation of international agreements into on-ground management actions was not a linear process as they were interpreted and reinterpreted along the policy pathway. As such, their effectiveness may be diluted. A disconnect between broad goal statements and on-ground action meant international agreements were not always useful to on-ground practitioners. The major policy gap affecting management of outcomes was the absence of a mechanism with which to manage cumulative impacts responsible for deterioration of ecosystem processes and biodiversity. Consequently, opportunities to distinguish policies and management actions that work from those that don’t, and why, may be limited. External factors affecting MPAs are many and significant, yet due to limits of jurisdictional responsibilities, on-ground managers are limited in influencing key factors that affect their areas of management. Despite the use of different policies in each jurisdiction, practitioner challenges were not always localised. A range of common and discrete challenges were identified in policy implementation processes. Resolving divergent and conflicting priorities and objectives, within and across agencies, was a difficulty raised in all jurisdictions. Political intervention was found to limit on-ground action, and practitioners were constrained in influencing key factors that impact on their capacity to address threats and manage outcomes. This research provides insight into the factors inhibiting effective implementation of international agreements, Commonwealth, and state policy, and that impact the ability of on-ground management to deliver positive outcomes.The second overarching aim of this thesis is to improve the objective evaluation of evidence in supporting or refuting the utility of MPAs to conserve biodiversity. To justify and support conservation measures, providing evidence that the outcome of the intervention is not attributable to any factor other than the intervention is a necessity. However, there is an identified gap between conservation theory and practice, and considerable scientific uncertainty about what interventions are successful, and the best approach to providing evidence of these impacts. To address this aim, I assessed what evidence was available to demonstrate the impact of a major policy intervention; the no-take zones in Australia’s Great Barrier Reef Marine Park. I found a paucity of data supporting causal relationships between newer protected zones (no-take or no-entry) and improvements in biological indicators; sampling was not designed to support causal inferences, and most data did not eliminate rival explanations for observed outcomes. Limited conclusions can be drawn regarding the impact of old and new no-take zones in the Marine Park. Impacts were varied, and a lack of trends makes it difficult to identify the trophic groups benefitting from no-take zones, other than those caught and consumed. For most trophic groups and non-target species, there were many more examples of neutral impacts than positive. If we are to better understand the opportunities for more effective interventions, we need a major overhaul of methods designed to provide and improve evidence of the impact of the Marine Park. This thesis identifies and highlights gaps between intentions and impacts in marine policy and practice across jurisdictions in Australia by providing a timely evaluation of the implementation of policy that underpins Australia’s MPA system, and the impact of policy interventions in conserving biodiversity. Such knowledge may enhance links between policy, practitioner, and on-ground management outcomes, and improve our ability to effectively measure the impact achieved through these practices.