The world’s last ice-free sea is in Alaska, but it is also home to one of the world’s most rarest and rarest species.
The tiny sea turtle is called the Alaskan sea turtle, and its species was only discovered in 1979.
But thanks to climate change and its natural predators, the sea turtle has shrunk by up to 75 per cent since then.
“It is one of those species that you can see in movies and books that are really spectacular,” said James Wahlberg, a marine biologist at the Smithsonian Institution who has been tracking the sea turtles for decades.
“They are so unique.”
So what is the sea creature’s secret?
First, the Alaska sea turtle lives in a specialised niche, one that’s more difficult to study than its northern cousin, the giant squid.
“The Alaskans have very specialized marine ecosystems,” said Wahlovans colleague Andrew Naylor, who was not involved in the research.
“These are very specialised environments.
There are very few other species of animals that live in those conditions.”
That makes them particularly vulnerable to climate changes, and that makes them especially vulnerable to disease and predation.
In the past few decades, the marine turtles’ populations have shrunk by about 40 per cent.
That’s an extraordinary decline.
The sea turtle’s genetic make-up has changed, too.
The species is now found only in a handful of locations in the Pacific and Indian Oceans, including Hawaii, the Cook Islands and the South China Sea.
In all, the islands have lost more than 50 per cent of the population of Alaskas giant sea turtles, which can reach up to 50 metres (130ft) in length.
And those numbers have dropped so fast that a single island now has a population of just seven to eight, according to Wahlenberg.
The Alaskanas giant sea turtle “has not recovered in the wild since the 1980s,” he said.
“That’s probably one of their greatest threats to the species.”
The sea turtles’ habitat is also less protected.
“There is a very limited amount of protected areas in the area and they’re only found in these very special conditions,” he explained.
“So if you have a sea turtle and it goes into a protected area, then that protected area is gone forever.”
But in some places, such as in the Cook Sea, the area has been turned into a thriving, thriving habitat.
“This is a huge threat to the survival of the species,” said Naylor.
“A lot of the fish populations that live there are threatened by climate change.
There is a lot of habitat loss.
It is just a matter of time before there’s extinction of the sea urchins in that area.”
It’s not just the sea creatures in the sea that are at risk.
“Climate change has been a really devastating blow to this species,” Wahlburg said.
The Arctic is also the region with the greatest chance of losing the sea otter.
It’s also one of only a handful where there is a sea otters population in a stable state, and only one of many where the otters are declining.
“I think this is one reason why climate change is such a major threat to sea otting,” he added.
“Sea otters have an extraordinary capacity to find food in the oceans.
If we lose sea ottering, then we will lose a lot more food.”
What to do about it?
The Arctic sea turtle isn’t the only species in the ocean that is experiencing an extinction-level event.
The last ice age, about 14,000 years ago, was a time when the oceans were very cold, but warming oceans meant the sea was much warmer.
The ice-covered ocean was covered by a thin layer of ice, and the sea wasn’t able to warm enough to break through that layer of water.
Scientists call that an ice-age sea.
It meant the ocean was much less dense than it is today.
“If we’re going to survive in this era, we’re all going to need to be able to cope with the changes that we see,” Wellberg said.