The current global conservation target set by the Convention on Biological Diversity aims to protect at least 30% of land and ocean by 2030. However, this target has two major limitations: it does not specify the amount of biodiversity to be included, nor does it define what “protection” entails in practice. Our global analysis of 77,880 marine, freshwater, and terrestrial species distribution indicates that all species could be protected within 50% of the land and sea, with 96% in 40%, 69% in 30%, and 58% in 10%. This optimal network, termed Representative Biodiversity Areas (RBA), reveals that the current “30% by 2030” target may only protect up to two-thirds of all species, underscoring its inadequacy.
For marine conservation, the location of the 30% protected areas is crucial. The West Pacific region, as the most species-rich marine area globally, is especially significant. Our systematic analysis in this region uses data-driven measures from species to ecosystems, from sea surface to seabed, at a spatial resolution of 0.5° (~55 km latitude). The study mapped the optimal RBA for West Pacific countries using decision support software, considering ecosystems defined by physical, biochemical, and nutrient variables, as well as species richness, seagrass, kelp, mangrove, shallow water coral reef biomes, and seabed topographic variation.
The findings show that protecting 30% of the area generally covers 30% of ecosystems, over 77% of seagrass, kelp, mangrove, and shallow water coral biomes, and 60% of physical habitat heterogeneity and species-rich areas. However, to protect the distributions of 80% of species in the region, at least 53% of the area should be under protection. Presently, only 25% of the RBA is within Marine Protected Areas (MPAs), with less than 1% in no-take MPAs. Indonesia, Australia, and New Zealand hold almost half of the RBA, while 11 countries have more than 30% of their Exclusive Economic Zones in these areas.
To achieve the 30% by 2030 target, opportunities exist to expand, merge, and increase the protection levels of existing MPAs, including areas of disputed or shared governance. Systematic conservation planning could protect at least twice as much biodiversity per area and may require that at least half of the West Pacific Ocean be designated as MPA to protect all marine biodiversity. Thus, managing resources outside MPAs sustainably is vital to global biodiversity conservation efforts.
 

biodiversity,prioritisation,west pacific,marine protected area,systematic planning