Assessing the factors that contribute to Marine Protected Area (MPA) effectiveness and whether global protected areas of 30% can be achieved by 2030

The urgency for effective conservation to mitigate the rapid deterioration of our marine habitats, which provide ecological, social, and economic benefits, is widely recognised. Marine Protected Areas (MPAs) have emerged as a pivotal tool in marine conservation. However, global MPA performance varies, and employed management schemes differ. This report aims to investigate the factors which contribute to MPA effectiveness, therefore success, and assess the feasibility of achieving the global target to conserve 30% of habitats by 2030; outlined in the Kunming-Montreal Global Biodiversity Framework (GBF, Target 3). To achieve this, a systematic literature review was conducted, employing search-strings, inclusion/exclusion criteria, screening, eligibility reading and finally data extraction, to assemble relevant information. The primary database used was Web of Science (WOS) supplemented by Google Scholar and websites searches, leading to 49 studies in this review. MPA effectiveness was identified to be significantly driven by enforcement, MPA design and stakeholder engagement. Accordingly, effective MPA designs are characterized by NEOLI (no-take, enforcement, old (>10 years), large (>100km2), isolated) features, whereby the presence of more features resulted in higher species biomass increases. Adequate enforcement correlates with ‘Overall Management Success’ (OMS), ensuring adherence to rules and regulations within MPAs. Stakeholder engagement is associated with high compliance and positive perceptions of MPAs thus legitimacy. The development of global MPA coverage, currently at 8.19%, is seen by increasing trends. Whilst MPA spatial variations are significantly positively correlated with coastline length, Human Development Index (HDI) and conservation investment. By elucidating the factors contributing to MPA success, enhancement for both existing and future designations is expedited, supporting GBF Target 3. Overall, the analysis of factors contributing to MPA effectiveness reveal overlapping complexities.