Hard not to love great whales for their beauty and intelligence alone. But they are also among the greatest carbon recyclers on the planet:
A whale accumulates carbon through feeding and stores it in its body during its long lifetime. Some whales weigh up to 200 tonnes, with an average lifespan of 70 years. One species, the bowhead whale, is estimated to have a lifespan of 268 years.
When a whale dies, it sinks to the bottom of the ocean, where the carbon in its body is sequestered. The IMF estimates that each great whale sequesters 33 tonnes of CO2 on average, and that a tree absorbs only up to 22kg of CO2 a year. Tree-planting schemes are being seen as the cheapest and fastest method of taking CO2 out of the atmosphere, but the evidence suggests conserving and boosting whale populations also has great carbon-capturing potential…[snip]
…Whales do more for carbon capture when they are alive, however, thanks to their jumbo-sized poo. These “faecal plumes” contain enormous amounts of nutrients – including phosphorus, iron and nitrogen – that are essential for the growth of microscopic organisms known as phytoplankton. When these plants photosynthesise, they consume carbon dioxide and produce oxygen. The IMF calculates that phytoplankton are responsible for capturing about 37 billion tonnes of CO2, the same as 1.7 trillion trees, or four Amazon forests’ worth. They also contribute as much as 50-85% of the oxygen in the Earth’s atmosphere. The famous National Geographic ocean explorer Sylvia Earle has estimated that they provide the oxygen for one in every five breaths we take.
Scientific research shows that whales have a “multiplier effect”, increasing phytoplankton production wherever they are found. As well as bringing nutrients from the ocean’s depths to the surface through their vertical movement, called the “whale pump”, whales also distribute them laterally on their vast migrations, a phenomenon named the “whale conveyor belt”.
Great whales are by far my favorite example of “Everything is connected.” Let’s let them be, so they can do what they do.