It is one of the most magical sights in nature. Tail sailing: when the tail of a whale crests above the water.

In 2022, photographers captured a humpback whale tail sailing off the coast of ZanzibarA group of islands off the coast of Tanzania. . When scientists studied the whale's markings, they realised the same animal had been spotted before, 13,000km away off the Pacific coast of Colombia. According to marine expert Dr Ekaterina Kalashnikova, the journey was "truly impressive and unusual".¹

The journey was likely caused by climate change. Shortages in krill - the shrimp-like creatures that humpback whales feed on - have forced them to travel further in search of food. Alternatively, it may have been looking for new breeding grounds.

In the 19th and 20th Centuries, industrial fishing depleted whale populations. By the 1960s, humans were hunting 80,000 whales a year and many breeds faced extinction. But commercial whaling was made illegal in the 1980s.

Whales consume carbon-rich food, which they then store in their bodies. An average whale can capture 33 tonnes of carbon dioxide during one lifetime; by comparison, an oak tree captures just 12 tonnes.³

Whale poo is also a rich source of nutrients for phytoplanktonVery small plants that float near the surface of water. Sea creatures feed on them. . Together, these microscopic creatures capture 40% of carbon on the planet - the equivalent of 1.7 trillion trees.

But whales are still at risk. Some 300,000 whales, dolphins and porpoises die each year from being trapped in fishing gear. Six out of 13 great whale species are classified as endangered or vulnerable. Warming polar regions also make it harder for them to find food.⁵

As the 13,000km journey shows, these are some of the most remarkable animals on the planet. Whether or not humans benefit from their survival, whales will benefit from protected habitats and restored populations.

Could these gentle giants save the planet?

Yes: Whales can capture 33 tonnes of carbon over the course of their life, as well as providing nutrients for phytoplankton. Restored whale populations are vital to climate resilience.

No: Whales remain at risk from busy shipping lanes, intensive fishing and water pollution. Rebounding populations are good news, but more must be done to protect these animals.

Or... Restoring whale populations will not reverse all the damage humans have done to the environment. But this one whale's 13,000km journey shows why we should still care about protecting them.