While we tend to think of forests as the world’s primary natural carbon sinks, that’s only true on land. When it comes to our oceans, a huge carbon sink comes in an unexpected form: whales. That’s right, these amazing mammals store humongous amounts of carbon dioxide in their bodies as they grow, and they take it down to the bottom of the ocean when they die, storing it there for centuries.
A whale fall — or the event when the carcass of a whale falls onto the ocean floor — can store tonnes of carbon dioxide, keeping it away from the atmosphere for centuries. In fact, recent research at marine sanctuaries in San Francisco found that whale falls represent roughly 60 percent of annual carbon storage in the marine environment, reports euronews.
A 2019 report by the International Monetary Fund (IMF) stated that great whales are the carbon capture titans of the marine world. According to the report, each great whale sequesters 33 tons of CO2 on average, storing that carbon onto the seafloor at the end of their lives. Overall, the IMF estimates that whales have the potential to capture 1.7 billion tonnes of CO2 annually if we allow them to restore to their pre-whaling numbers.
Not only that, whales also play an important role in the production of phytoplankton by providing these tiny microorganisms with valuable nutrients. The mammals’ iron-rich feces promotes the growth of the tiny marine algae, which capture around 40 percent of all CO2 emitted in the world.