California officials say juvenile coho salmon have been documented in a tributary of the Russian River in Mendocino County for the first time since 1991.

The Arctic report card shows hottest decade on record and sea ice coverage dropping 28%. Vanishing ice increases global warming as 'Earth's air conditioner' changes.

For deep reef divers, descending into the ocean’s mesophotic layer can feel like exploring the moon. Discovering never-before-seen marine species is part of the mission.

Listen to this episode from Deep Water | Tortoise Investigates on Spotify. After weeks of chasing him, Lydia finally speaks to Vitomir Maričić, the Croatian freediver at the heart of the scandal – and he tells his side of the story.Subscribe to Observer+ on Apple Podcasts and Spotify to binge listen to the entire series on Tuesday 18th November.To find out more about The Observer:Subscribe to TheObserver+ on Apple Podcasts for early access and ad-free contentHead to our website observer.co.uk Reporter - Lydia Gard Producer - Gary Marshall. Music supervision and sound design - Karla PatellaSound design - Rowan BishopPodcast artwork - Lola Williams Fact checking - Poppy Bullard, Katie Gunning, Amalie Sortland, Madeleine Parr & Jess Swinburne Executive producer - Basia Cummings Hosted on Acast. See acast.com/privacy for more information.

The 20th anniversary of the annual report tracks how sea ice, snow cover and many other vital signs of the Arctic have changed, and the impact that’s having on people and wildlife.

The Trump administration announced a plan to pump more water in California's Sacramento-San Joaquin River Delta. Democratic lawmakers condemn it as a 'political stunt.'