A study led by Graham Edgar and colleagues found that marine protected areas (MPAs) with five key features—no-take zones, effective enforcement, age (>10 years), large size (>100 km²), and isolation by deep water or sand—significantly enhance conservation outcomes. These features lead to higher fish biomass, species richness, and shark biomass compared to fished areas. Effective MPAs with four or five features showed a 244% increase in total fish biomass, 840% in large fish biomass, and 1,990% in shark biomass. However, MPAs with fewer features often did not differ significantly from fished areas. The study highlights that global conservation targets based solely on area are insufficient, and better MPA design, management, and compliance are needed. The research used data from 87 MPAs across 40 countries, showing that MPAs with five NEOLI features had 36% higher large fish species richness and 35% higher large fish biomass than fished areas. Despite these findings, many MPAs had fish biomass below predicted averages, indicating variability in site-specific conditions. The study also found that fishing has drastically reduced fish biomass, with 63% of all fish biomass, 80% of large fish biomass, and 93% of shark biomass removed from reefs. The results emphasize the need for effective MPAs to protect marine biodiversity, as current global MPA coverage is low. The study underscores the importance of considering multiple factors in MPA design and management to achieve conservation goals.A study led by Graham Edgar and colleagues found that marine protected areas (MPAs) with five key features—no-take zones, effective enforcement, age (>10 years), large size (>100 km²), and isolation by deep water or sand—significantly enhance conservation outcomes. These features lead to higher fish biomass, species richness, and shark biomass compared to fished areas. Effective MPAs with four or five features showed a 244% increase in total fish biomass, 840% in large fish biomass, and 1,990% in shark biomass. However, MPAs with fewer features often did not differ significantly from fished areas. The study highlights that global conservation targets based solely on area are insufficient, and better MPA design, management, and compliance are needed. The research used data from 87 MPAs across 40 countries, showing that MPAs with five NEOLI features had 36% higher large fish species richness and 35% higher large fish biomass than fished areas. Despite these findings, many MPAs had fish biomass below predicted averages, indicating variability in site-specific conditions. The study also found that fishing has drastically reduced fish biomass, with 63% of all fish biomass, 80% of large fish biomass, and 93% of shark biomass removed from reefs. The results emphasize the need for effective MPAs to protect marine biodiversity, as current global MPA coverage is low. The study underscores the importance of considering multiple factors in MPA design and management to achieve conservation goals.