The oceans absorb massive amounts of carbon dioxide from the atmosphere every year. They naturally process and recycle carbon keeping ocean conditions regulated and balanced for marine life to survive and thrive. However, by absorbing excessive amounts of carbon from our atmosphere that balance becomes overwhelmed and results in increasingly warmer ocean temperatures and increasing ocean acidification (Rising acidity levels in the oceans) ... and with that can come the collapse of ocean ecosystems. It’s an extremely real threat that’s already happening you can read more on ocean acidification here.
Humans are investing heavily into carbon capturing systems along with making massive strides in the renewable energy sector but we are still years away from seeing this on a global and commercial scale. Nature however, also has its own heroes who are unknowingly combating carbon dioxide. The majestic whale is one of the biggest carbon capturing animals on the planet. That’s right, our massive blubbery friends are living carbon capturing units.
Most species of baleen whales capture over 30 tons of CO2 from our atmosphere during their lifetime. That’s a massive amount of carbon that gets captured and stored in their bodies.
For those wondering, a single mature tree captures over 20 kg of CO2 per year. The lifespan of a tree can be far greater than a whale and there's far more trees on the planet in comparison, so trees collectively are pulling far greater amounts of carbon from our atmosphere than whales. However one downside is that a bushfire can release that stored carbon back into the atmosphere as the tree burns, a whale on the other hand eventually sinks to the bottom of the ocean when they die, effectively removing carbon from our atmosphere for hundreds of years or more, they are a literal “carbon sink”.
If they weren't already amazing enough, the whale's carcass on the ocean floor is known as a "whale fall" and provides nutrients for marine animals and organisms for decades as it decomposes.
Whales do far more than just capture carbon.
Whales in addition to capturing and storing carbon from our atmosphere, also help support another function of the ocean that’s crucial for life on Earth – They stimulate the growth of phytoplankton.
Phytoplankton are microscopic organisms that produce around 50% of the oxygen we breathe. On top of this phytoplankton pull well over 30 billion tonnes of carbon dioxide out of our atmosphere by using photosynthesis, which is the equivalent of around four amazon rainforests!
So how does the whale help phytoplankton growth? and what does this have to do with anything?
When a whale “goes to toilet” they release huge amounts of nutrients into the ocean. Their waste is full of nutrients and minerals including Iron, Nitrogen, Phosphorus. These massive plumes of minerals feed and act as fertiliser that stimulates the growth of phytoplankton. It's estimated that a 1% increase in the current global phytoplankton population is the equivalent of around 2 billion mature trees.
This was proven from studies carried out in the southern ocean that found 12,000 sperm whales were stimulating the growth of phytoplankton from their waste. This was resulting in hundreds of thousands of tonnes of carbon being captured by the phytoplankton. So more whales equals more phytoplankton growth which equals even more carbon being captured.
We spoke about the phytoplankton in a previous article about how these little organisms are critical to producing most of the oxygen we breathe, and also how they are ultimately at the mercy of the increasing acidity levels in our oceans. You can read that article here.
Whale populations are now only a small portion of what they once were. Biologists estimate that there are a little more than 1.3 million whales currently in the ocean, which is a quarter of their previous populations of around 4 to 5 million before they were hunted during the whale booms. The populations of some species, such as the blue whale, have been reduced to as little as 3%.
Recovering the populations of whales is a significant means to promote the carbon absorption potential of the ocean, as well as its health and oxygen production capacity. The International Monetary Fund has gone as far to put an economical value on the whale populations being worth around $1 Tillion dollars to the global economy.
While nature does an amazing job, preserving the planet for all living creatures for generations to come is everyone's responsibility. We need to understand the importance of each living thing on the planet in order to take solidarity actions to preserve it.