野生生物種の個体群の大きさ、５０年で７３％減少 ＷＷＦ

【パリＡＦＰ＝時事】世界自然保護基金（ＷＷＦ）が１０日公表した自然界の現状を科学的知見に基づいてまとめた「生きている地球レポート（ＬＰＲ）」の最新版によると、対象の野生生物種の個体群を分析した「生きている地球指数（ＬＰＩ）」で、対象の脊椎動物種の個体群の大きさが過去５０年間で平均７３％減少した。（写真は資料写真）
　ＬＰＩは、５０００種以上の脊椎動物（哺乳類、鳥類、両生類、爬虫（はちゅう）類、魚類）における３万５０００の個体群の調査に基づいている。最新版で、世界中で個体群の大きさの減少が加速していることが示された。
　中南米・カリブ海などの生物多様性に富んだ地域では、個体群の大きさが最大で９５％減少した。
　指数の変化率は、動物個体群の大きさの平均的な比例変化を反映したもので、失われた個体数や個体群の数ではない。
　分析対象の脊椎動物種の個体群の大きさは、１９７０年からの５０年間で、７３％減少した。そのほとんどは人類による圧力が原因だとされる。
　ＬＰＩは国際的な基準となっており、今月コロンビアで開催される国連（ＵＮ）生物多様性サミットでもこの指数に焦点が当てられる。
　生息環境ごとの変化では、最も減少が著しいのは淡水域の８５％で、陸域の６９％、海域の５６％と続く。
　ＷＷＦフランスのヤン・ロランス氏は、「われわれは海域の生物量の４０％を枯渇させてしまった」と述べた。
　地域ごとの変化では、最も減少が著しいのは中南米とカリブ海の９５％で、アフリカの７６％、アジア・太平洋地域の６０％と続く。
　これらの地域と比べると、欧州と中央アジア、北米では減少傾向が「顕著ではない」。
　報告書によると、種の保全と種の再導入のおかげで、一部種の個体群の大きさは安定しており、増加している種もある。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2024/10/10-18:09）

Wild populations of monitored animal species have plummeted over 70 percent in the last half-century, according to the latest edition of a landmark assessment by WWF published on Thursday.
Featuring data from 35,000 populations of more than 5,000 species of mammals, birds, amphibians, reptiles and fish, the WWF Living Planet Index shows accelerating declines across the globe.
In biodiversity-rich regions such as Latin America and the Caribbean, the figure for animal population loss is as high as 95 percent.
The report tracks trends in the abundance of a large number of species, not individual animal numbers.
It found that populations under review had fallen 73 percent since 1970, mostly due to human pressures.
The index has become an international reference and arrives just ahead of the next UN summit on biodiversity, which will spotlight the issue when it opens in Colombia later this month.
The picture we are painting is incredibly concerning, said Kirsten Schuijt, Director General of WWF International, at a press briefing.
- Tipping points -
This is not just about wildlife, it's about the essential ecosystems that sustain human life, said Daudi Sumba, chief conservation officer at WWF.
The report reiterates the need to simultaneously confront the interconnected crises of climate change and nature destruction, and warned of major tipping points approaching certain ecosystems.
The changes could be irreversible, with devastating consequences for humanity, he said, using the example of deforestation in the Amazon, which could shift this critical ecosystem from a carbon sink to a carbon source.
Habitat degradation and loss, driven primarily by our food system, is the most reported threat in each region, followed by overexploitation, invasive species and disease, the report said.
Other threats include climate change, in particular in Latin America and the Caribbean, and pollution, notably in North America, Asia and the Pacific.
- 'Incredibly concerning' -
The biggest decline is found in populations of freshwater species, followed by terrestrial and marine vertebrates.
We have emptied the oceans of 40 percent of their biomass, said Yann Laurans of WWF France.
Continent by continent, the average decline reached 95 percent in Latin America and the Caribbean, followed by Africa, down 76 percent, and then Asia and the Pacific, which declined 60 percent.
The reduction in populations is less spectacular in Europe, Central Asia and North America.
Some populations have stabilised or even expanded thanks to conservation efforts and the reintroduction of species, the report said.
The European bison, for example, disappeared in the wild in 1927 but in 2020 numbered 6,800 thanks to large-scale breeding and successful reintroduction, mainly in protected areas.
While calling the overall picture incredibly concerning, Schuijt added: The good news is that we're not yet past the point of no return.
She pointed to global efforts including a breakthrough pact landed at the last UN meeting on biodiversity in 2022 to protect 30 percent of the planet by 2030 from pollution, degradation and climate change.
But she warned, all of these agreements have checkpoints in 2030 that are in danger of being missed.
Several scientific studies published by the journal Nature have accused WWF of methodological biases in its index that lead to an exaggerated extent of the decline of animals.
We remain really confident of its robustness, said Andrew Terry of the Zoological Society of London at a press briefing, highlighting the use of a range of indicators, looking at extinction risk, biodiversity and ecosystem health to really broaden that picture.