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How whales regulate the marine circular economy & the climate

Why understanding living systems is essential for innovation.

Once you understand how life works, you will see that the life that prevailed over millions of years of change and disruption, is the life that leaves the planet better off than before by creating conditions that are beneficial to life. Something we as humans are only beginning to acknowledge. One of the most astonishing examples comes from the stewards of the oceans—the great whales.

It was investigative zoologist and journalist, George Monbiot, who first popularized the story through his compelling piece, “Why whale poo matters.“ In the 1970s, people believed that a great reduction in the whale population would lead to an increase in krill and fish, both of which are commercially important for our economy. The hunt was open. Industrial whaling became such a profitable business that it reduced the number of great whales at an alarming pace, bringing them to the verge of extinction in just a few decades. But the great decline in whales did not increase the number of fish or krill. On the contrary, as we are learning now that instead of increasing krill and fish populations, the great decline in whales may have led to a decline in fish stocks.

In the areas where whales were hunted most intensively, the volume of plant plankton went down. Plant plankton is the main food source for krill, which is the main food source for fish, and both fish and krill are the main food sources of many whales. So how do whales contribute to the production of plant plankton? Well, whale excrement is rich in iron and nitrogen, which are scarce in marine surface waters. Both elements are important fertilizers for plant plankton to grow. Now, although whales usually feed at great depths, they have to swim to the surface regularly to breathe and defecate. Their plunging up and down is called the “whale pump” in scientific literature as it causes vertical mixing of the water. This mixing supports the vertical transfer of nutrients from the deep sea to the upper photic zone, the only zone where photosynthesis is possible, and where plankton reproduce.

It is estimated that the whales’ up and down movements contribute as much to mixing the water than the effect from wind, waves, and tides combined. Whales are thus important vectors of nutrient and material flux in the oceans. They are the stewards that keep the marine circular economy going. These aquatic giants thus not only affect the oceanic ecosystem, they influence the physical factors of the ocean as well. Plant plankton absorbs carbon from the atmosphere, and when they ultimately die and sink into the abyss, they sequester that carbon onto the ocean floor where it is stored for millions of years. It is hard to estimate just how much “carbon drawdown” is accumulated by the oceans, but studies suggest billions of tons of carbon are pulled down every year. So, more whales means more plant plankton, which means more carbon sequestration.

But that is not the end of the story. Just like terrestrial plants, marine plankton gives off a chemical signal, called dimethyl sulfide (DMS), when it experiences stress from predation or UV radiation. DMS attract predators like albatrosses and other sea birds that eat the marine creatures who graze on the plant plankton. Not only do these birds help protect the plankton, they also leave droppings, rich in nutrients, that further enhance plankton’s reproduction. DMS is also an important chemical involved in global climate regulation. When the sun burns too hot, the chemical filters into the air, where it acts as a nucleus for condensation—a.k.a. a cloud. So, plankton makes clouds when the UV light stress is too high, and more white clouds means more reflection and a smaller surface of dark water to absorb the heat from the sun. This is known as the albedo effect (the amount of electromagnetic radiation that is reflected, rather than absorbed), and it is an important cooling mechanism of the planet. And the thread of interdependency continues—more whales means more plankton, which means more carbon drawdown, which means more sunlight reflected into space. And the story continues still.

New research suggests that the impact of industrial whaling not only altered marine ecosystems, but coastal ecosystems as well. With fewer Great Whales in the oceans, killer whales, who eat great whales, have since changed their diets. Killer whales, also known as orcas, have started to hunt for seals and otters instead, which has radically reduced the number of sea otters in the North Pacific. And sea otters play an important role in maintaining the health of underwater kelp forests. These kelp forests are one of the richest coastal ecosystems on Earth, and not only do these underwater jungles protect the coastlines from storms, they are also champions in drawing down carbon from the atmosphere, sequestering carbon as effectively as their terrestrial counterparts, the rainforests. Now, sea otters feed on sea urchins, the grazers of the kelp forests. But with fewer and fewer sea otters—having been eaten by the orcas who can’t find enough Great Whales—sea urchin populations have exploded and are now decimating the underwater forests through overgrazing. So fewer great whales means fewer sea otters, which means dwindling kelp forests, which means less carbon storage and a weaker buffer against coastal storms.

Not only does this example illustrate how everything is interconnected and interdependent here on Earth, but it also illustrates how important keystone species, like whales and otters, are. These species maintain valuable ecosystems with their activities. That is why scientists call them ecosystem engineers. But that does not cover the magnitude of their contribution. Their activities create benefits that cascade well beyond their ecosystems, to the land and into the atmosphere. They are the custodians of a stable, life-friendly and viable biosphere because they play a vital role in climate regulation. And it is not only large organisms that generate substantial impact, microscopic creatures play vital roles too.

The International Monetary Fund (IMF) conducted a study that highlights how plant plankton not only contributes at least 50% of all oxygen to our atmosphere, they do so by sequestering about 37 billion tons of carbon dioxide each year. This is about the same as the carbon drawdown potential of four mature Amazon forests. The study also shows that if whales were allowed to return to their pre-whaling number of four to five million (it is estimated that there are about one million left today), it could significantly add to the amount of phytoplankton in the oceans and consequently to the carbon that is drawn down into the oceans each year. Researchers calculated that even a 1% increase in phytoplankton productivity—thanks to whale activity—would sequester hundreds of millions of tons of additional carbon a year.

With this knowledge, it’s time to think beyond technological solutions to reverse climate change. Restoring the oceans so that whales and sea otter populations can return to their original numbers may be a solution that is not only cheaper, but more effective and less risky than many proposed man-made, high-tech alternatives like geo-engineering. According to the study, restoring whale populations could lead to a breakthrough in the fight against climate change. The researchers involved state that “healthy whale populations imply healthy marine life including fish, seabirds, and an overall vibrant system that recycles nutrients between oceans and land, improving life in both places. The ‘earth- tech’ strategy of supporting whales’ return to their previous abundance in the oceans would significantly benefit not only life in the oceans but also life on land, including our own.”

Not only that, fish stock and tourism would benefit from the return of whales and otters. The IMF study estimates that the current number of whales actually contribute more than $1 trillion to our economy in terms of carbon sequestration, ecotourism, and the fishing industry. Another study estimated that the carbon storage service of an underwater kelp forest is worth between $205-408 million per year, and this is probably a conservative estimate. We humans need to think in ecosystems instead of in isolated technologies, because so far, we have not been able to design a technological solution that does not cause other problems elsewhere. Besides, the associated economic benefits of ecosystem restoration may outclass even our best engineering approaches.

The accounts above also illustrate the critical role that keystone species play. Restoration efforts, therefore, will be easiest and most effective if they go hand in hand with strategies to improve life for keystone species that play an essential role in maintaining these natural carbon sinks and keeping our environment healthy, because the real world does not operate in the reductionist machine logic that has dominated our thinking for so long. It is not only abiotic features (the non-living chemical and geological elements of the environment) that influence living organisms and the functioning of ecosystems. Organisms also affect the physical geography of the land, oceans, and even the atmosphere.

And left to their own devise, the living world affects the non-living world in a way that increases the health, wealth, vitality and viability of the entire biosphere. That is the way life works. Fungi, foxes, whales, phytoplankton, otters and many other species all play an important role in maintaining a healthy climate and life enhancing environment, and we need them to play their part. Or, in the words of evolutionary biologist and futurist Elisabet Sahtouris: “The best life insurance for any species in an ecosystem is to contribute usefully to sustaining the lives of other species, a lesson we are only beginning to learn as humans.”

Excerpt from the book "Building the Future of Innovation on millions of years of Natural Intelligence" (2020). Scientific references underpinning the story can be found in the book.


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