Total ecosystem service benefits of achieving 10% coverage of MPAs have been estimated at USD 622-923 billion over the period 2015-50. This includes substantial efforts in enhancing the design and implementation of MPAs, as evidence suggests that in many cases they are not meeting their intended objectives. This report therefore considers the benefits and costs of MPAs, key issues in effective design and implementation, scaling up finance for MPAs, and the need for effective policy mixes. Clearly define the goals and objectives of the MPA, and the required level of protection to achieve these.