The costs of poor ocean management practices include environmental and social costs that are often not factored into decision-making processes. This undermines the resilience of the ecosystems upon which we depend, for food, for income, but also other less visible life-support functions such as coastal protection, habitat provisioning and carbon sequestration.

The state of marine biodiversity and ecosystems is degrading at an alarming rate. It is estimated that 60% of the world’s major marine ecosystems have been degraded or are being used unsustainably. Many fisheries are over-exploited, with some stocks on the verge of collapse, and coral reefs are bleaching due to exposure to high temperatures and other pressures. Concurrently, pollution from land-based sources, including marine litter, is threatening species and marine habitats, and climate change compounds these effects and alters both the thermal and chemical characteristics of the ocean as well as its dynamics and nutrient availability. Since the 1980s, for example, an estimated 20% of global mangroves have been lost and 19% of coral reefs have disappeared. The welfare costs that this imposes on society are high and pressures from human activities are projected to grow.

This chapter provides an overview of the trends in the state of, and pressures on, marine biodiversity; the economic values associated with marine ecosystems; and the types of policy instruments that are available for the conservation and sustainable use of marine biodiversity. It then discusses the role of marine protected areas and summarises their current use and trends. Drawing on the key findings from the publication, the chapter concludes with good practice insights for more effective design and implementation of marine protected areas.

This chapter highlights the need to better understand the benefits and costs associated with marine protected areas (MPAs). It then provides a review of the valuation literature on marine protected areas, drawing on studies from around the world. It concludes with a brief overview on how cost-benefit analysis can be used to inform MPA decision making.

This chapter examines key issues that need to be considered for the effective design and management of marine protected areas (MPAs). These include setting clear goals and objectives; determining the appropriate siting, size and number of MPAs; robust monitoring and reporting; ensuring effective compliance and enforcement; and putting in place effective MPA governance frameworks.

A frequently cited challenge for more effective management of marine protected areas (MPAs) has been their inability to secure sufficient and sustainable financing. This chapter examines the various financing instruments and approaches that are available, ranging from traditional government budget and donor funding to user fees, taxes and fines, and payments for ecosystem services, among others. The chapter concludes with a discussion on the need to develop finance strategies for MPAs, drawing on examples from different countries.

Though marine protected areas are often necessary to ensure the conservation and sustainable use of marine resources, they are not always sufficient. This chapter highlights the need for effective policy mixes to address the multiple and sometimes cumulative pressures on marine biodiversity. It provides a framework for designing and evaluating policy mixes. The role of marine spatial planning, and other instruments, such as fish catch regulations and water pollution control measures, are discussed.