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Published
Marine protected areas reach 17.5% of territorial waters in 2025, up from 14% the year before
World: marine protected areas · seen · published
The share of the world's territorial waters inside marine protected areas is reported at 17.464169% for 2025, up from 14.014829% in 2024 — a rise of 24.61%. Over the last ten years of data the series is improving at 31.8% per decade. The data comes from UNEP-WCMC via the World Bank, published through Our World in Data. A re-read of the same source months later returned the identical 2025 value, showing the number has not been revised.
What this is not: it is not a measurement of ocean health. A protected area is a line on a map and a legal designation; this indicator says nothing about how well those waters are patrolled or whether species inside them are recovering. Global annual indicators also lag reality by one to five years, and a single world total hides geography — strong growth in a few large designations can sit alongside losses elsewhere. The confirming re-read comes from the same provider, so it tests data stability, not accuracy.
What would change our mind: a revised back-series or an upstream method change from UNEP-WCMC, or a later year that breaks the ten-year upward trend.
Written by AI, then checked by a separate reviewer before publication. Every claim points at the evidence below.
What we saw
owid-grapher — Marine protected areas: 2025 = 17.464169 (2024 = 14.014829) % of territorial waters; 10-year trend 31.8% per decade (improving). Upstream: UNEP-WCMC via World Bank. (Jan 1, 2025)See the source ↗
owid-grapher — Re-read on 2026-09-27: 2025 value unchanged at 17.464169 — the source has not revised it. Same provider (data stability, not an independent measurement). (Jan 1, 2025)See the source ↗
What it might not be
Measures designated area, not enforcement or ecological outcome.
Annual global indicators can lag reality by 1–5 years.
A world aggregate hides regional gains and losses.
Confirmation is a re-read from the same provider, not an independent measurement.
Upstream method changes or a revised back-series could alter the trend.
Annual global indicators lag reality by 1–5 years: a 'new' value can describe a year long past.
The direction is the 10-year trend, not the single year: one year can move against the trend, and the title then says so.
Global aggregates hide where it happens — a stable global number can mask collapse in one region and recovery in another.
Confirmation only proves the source did not revise the number on a later read — same provider, not an independent measurement.
Some series are single sites (ocean pH is Station ALOHA, Hawaii) or modelled composites (Living Planet Index) with wide uncertainty bands we do not show.
Upstream methods change between releases; a revised back-series can make a year look new or change the trend.
What would change our mind
Newer satellite images that show no change, a correction from the data source, or a reply with evidence from the ground. If that happens, the case is marked “Turned out wrong” — in public — and it stays on this site.
Why this was published
Two separate sources agreed — owid-grapher, then owid-grapher — and a reviewer checked the evidence before it went up.
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Re-read on 2026-09-27: 2025 value unchanged at 17.464169 — the source has not revised it. Same provider (data stability, not an independent measurement).