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Ecosystem Profile

Freshwater Ecosystems

Rivers, lakes, and wetlands cover under 1% of the planet's surface — yet freshwater wildlife populations have collapsed faster than any other biome monitored by the Living Planet Index.

Published May 2026 Last reviewed October 2026 Evidence level Strong Reading time 6 min

Overview

Freshwater ecosystems — rivers, lakes, wetlands, and floodplains — cover a small fraction of the Earth's surface but support a disproportionate share of global biodiversity, including roughly half of all known fish species. They are also, by a clear margin, the most rapidly declining biome tracked by long-term monitoring.

Established fact

WWF's 2026 Living Planet Report found an 85% average decline in monitored freshwater wildlife populations between 1970 and 2022 — still the steepest of any ecosystem type, ahead of terrestrial (−69%) and marine (−59%) populations. The previous, 2024 edition had separately reported an 81% decline in migratory freshwater fish populations over 1970–2020.

Source: WWF Living Planet Report 2026 and 2024; Zoological Society of London

Wildlife & Biodiversity

Freshwater habitats support an estimated one-third of all vertebrate species despite covering less than 1% of Earth's surface area, a concentration of biodiversity that makes freshwater decline disproportionately significant for overall species loss trends.

Pressures

River fragmentationDams and other barriers block migratory fish species from reaching spawning grounds; the Living Planet Report identifies river fragmentation as one of the two most common pressures on freshwater wildlife.
Water abstractionWithdrawal of water for agriculture, industry, and municipal use reduces river flows and can dry up wetlands entirely, particularly in already water-stressed regions.
PollutionAgricultural runoff, industrial discharge, and untreated wastewater degrade water quality across freshwater systems worldwide, compounding the direct habitat pressures of fragmentation and abstraction.

Regional Disparities

-95%Latin America and the Caribbean — the sharpest regional decline in monitored wildlife populations recorded in the 2026 Living Planet Index.
-80%Africa
-49%Asia–Pacific
-28%North America
-23%Europe and Central Asia
Editorial analysis

Two cautions apply when reading these figures. First, the regional indices cover terrestrial and freshwater populations combined, not freshwater alone. Second, successive Living Planet Reports aren't directly comparable: the 2026 dataset added 967 populations and 295 species and runs two years longer than the 2024 edition. Asia–Pacific moving from −60% (2024) to −49% (2026), for example, reflects a changed dataset rather than evidence of recovery. The lower North American and European figures also partly reflect that heavy losses there had already occurred before the index's 1970 baseline.

Uncertainty & Evidence Gaps

The Living Planet Index is based on trends in monitored populations (35,803 population trends across 5,790 species in the 2026 edition) rather than a full census, and monitoring coverage is denser in well-studied regions of Europe and North America than in parts of Africa, Asia, and Latin America where declines may be under- or over-represented.