Whales help mitigate climate change by dumping carbon into the ocean and taking more with them when they die, scientists say

Researchers investigate a humpback whale by boat and drone in surface waters near the West Antarctic PeninsulaDuke University Marine Robotics and Remote Sensing under NOAA permit 1 4809 – 03 and ACA permits 2015 – 011 and 2020 – 016

  • Whales are the largest animals on the planet, and their huge bodies play a role in the carbon cycle.

  • They capture carbon in their bodies throughout their lives and encourage biodiversity with their poo.

  • They act like carbon vaults by sinking to the ocean floor when they die, scientists have said.

Whales naturally help divert carbon from the atmosphere in life and death, scientists said in a review published Thursday.

Because they are so big – with the largest whales larger than dinosaurs – the amount of carbon they capture throughout their lifetime is substantial.

While not a solution to the climate crisis on its own, their ability to store carbon is another reason to encourage their numbers to rise in the oceans, scientists have said.

The results of their analysis have been published in the peer-reviewed journal Trends in Ecology and Evolution.

Whales naturally store carbon as they live their lives

Whales capture carbon primarily by pooping and dying. The diagram below explains how.

A diagram shows how whales help capture carbon from the atmosphere.  Two types of large whales poop, feed local phytoplankton growth, feed on plankton or plankton-eating animals, then die and sink to the ocean floor.

A diagram shows how whales help remove carbon from the atmosphere.Trends in Ecology and Evolution/Pearson

Every animal, big or small, is part of a carbon cycle. Carbon is present in all forms of life on Earth. Animals get carbon by eating plants and animal products, and plants get it from the atmosphere.

This carbon is either stored in the body until the animal dies or is released in the form of feces. These by-products are then nibbled on by other animals and plants, pumping that carbon back up the food chain.

When you’re as big as a whale, what happens to your body and your poop can have a huge effect.

“Because whales are so large, they have the potential to store large amounts of carbon,” study author and University of Alaska Southeast biologist Heidi Pearson said in an interview with Insider.

Whales weigh up to 150 tons and can live for over 100 years. That’s a lot of carbon stored in their bodies, away from the atmosphere, until they die.

“You can think of whales as big trees floating in the ocean,” Pearson said.

a humpback whale is seen from above, feeding.

A humpback whale feeds in the Stellwagen Bank National Marine Sanctuary.Elliott Hazen

Eat, poop and pee the ecosystem comes back to life

What they don’t store in their bodies, whales poop and urinate in the ocean.

Previous studies have shown that this is extremely important for the ecosystem. When whale populations plummeted after widespread whaling in the 1900s, plankton populations also plummeted unexpectedly.

This is because plankton feed on whale poop, so the disappearance of a single whale causes a huge deficit in the ocean ecosystem. This is called the whale pump effect.

By encouraging new life, whales create more organisms capable of capturing carbon from the atmosphere.

The whales can then feed on these new lifeforms, in enormous quantities, trapping this carbon in their bodies for many decades.

Finally, when they die, whale bodies tend to sink to the bottom of the ocean, where the carbon stays out of the atmosphere.

“It’s going to stay out of touch with the atmosphere for hundreds, thousands of years, maybe even longer. And whales do that naturally,” Pearson said.

A humpback whale bursts in.

Breaching Humpback Whale, Cabo San Lucas, Baja California.Getty Images

Not a quick fix

By encouraging the number of whales to grow, their carbon-locking effect can be amplified.

“We believe whales are worth conserving for many reasons. They are important parts of healthy ecosystems and they help promote biodiversity, given that we are also in a biodiversity crisis,” said Pearson.

“This potential climate benefit is just another reason,” she said.

Conservation today is less about whaling and more about creating protected areas in the ocean to avoid collisions with ships, keep the oceans calm and prevent whales from becoming entangled in fishing gear, Pearson said.

“Another big thing is climate change. So kind of come full circle,” she said.

Pearson cautioned, however, that she doesn’t think it should be seen as a viable solution to the climate crisis on its own.

Proponents of nature-based solutions suggest that by restoring biodiversity, such as planting trees and encouraging regeneration, a substantial amount of excess carbon in the atmosphere could be captured in living organisms.

It’s true, and this approach has obvious positive effects for the environment, but that’s not all.

Estimates suggest that nature-based solutions can provide 37% of the climate change mitigation by 2030 that is needed to meet the goal of keeping global warming below 2 degrees Celsius, according to the World Bank.

“They’re not the magic bullet. Even if we really could get some strong conservation measures and get whale populations back to pre-industrial abundance, that still won’t solve the climate crisis,” she said.

“It will be a small piece of everything we have to do,” she said.

Read the original article on Business Insider

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