Here's the mechanism failure, stated plainly: a country designates a marine protected area (MPA), reports it to UNEP-WCMC's World Database on Protected Areas, and that designation counts toward the 30x30 biodiversity target with essentially zero independent verification of whether extraction, fishing, or industrial activity inside the boundary actually stopped.

The only rigorous cross-check that exists -- The MPA Guide framework used by Marine Conservation Institute's MPAtlas -- is run by an NGO with a research budget, not a treaty body with enforcement power, and it currently covers a sample of MPAs in depth, not the full global inventory.

The scale of the discrepancy this produces is not small. Pike et al. 01% governments report as protected overall. A quarter of that assessed area was unimplemented -- protected on paper with no observable enforcement action -- and a third was actively incompatible with conservation, permitting fishing, trawling, or extraction inside boundaries labeled 'protected.'

The OECM (other effective area-based conservation measure) category compounds this. Cook et al. (2025, Conservation Letters) found the overwhelming majority of areas countries report as OECMs carry no supporting evidence of conservation credibility whatsoever -- no monitoring data, no enforcement record, nothing that would let an outside party confirm the claim.

This is not a hypothetical governance gap; it has already produced concrete reversals with no mechanism to contest them.

Chile's Kast administration reversed 337,000 km2 of marine protection enacted by the prior government in a single executive act, and no international body had standing to challenge the decision, because the original designation was never binding under a mechanism with enforcement teeth.

Executive orders in the United States are similarly unwinding protections across more than 3 million km2 of Marine National Monuments without triggering any external accountability process, because 'protected area' status has always been a domestic administrative designation rather than an internationally verified, legally durable commitment.

The structural problem: the entities that benefit from reporting high protection numbers (national governments seeking credit toward international targets) are the same entities solely responsible for verifying those numbers, and the one body that does independent quality assessment (MPAtlas) has no legal authority to compel correction -- only the ability to publish a competing estimate that most policymakers and headlines ignore in favor of the official figure.