The Ganges river dolphin is also in grave danger; only a few thousand remain, and they live in some of the most polluted rivers on Earth.

恒河河豚也是岌岌可危。 现仅存数千头，生活在地球上污染最严重的水域。

youdao

The site protects key threatened species including giant arapaima fish the amazonian manatee the black caiman and two species of river dolphin.

保护区为许多珍稀濒危动物提供保护，例如巨骨舌鱼、亚马逊海牛、黑凯门鳄和两种淡水豚类。

youdao

The site protects key threatened species, including giant arapaima fish , the amazonian manatee, the black caiman and two species of river dolphin.

保护区为许多珍稀濒危动物提供保护，例如巨骨舌鱼、亚马逊海牛、黑凯门鳄和两种淡水豚类。

youdao

But it's the Ganges river dolphin and the Irrawaddy dolphin which give the most cause for concern.

BBC: NEWS | South Asia | Bangladesh's majestic dolphins at risk

The Yangtze river dolphin made news because scientists think that it may now have been driven to extinction.

ECONOMIST: Conservation marketers choose land over beast

Earlier this year the baiji or Yangtse River Dolphin was declared probably extinct, and the Critically Endangered vaquita (Phocoena sinus) - another species restricted to a small, specific habitat - will follow suit without swift action, conservationists believe.

BBC: Finance woes put porpoise at risk