Underwater forests, known as kelp, have supported people and cultures for thousands of years. However, most of us are only dimly aware of the vibrant clumps of seaweed that hug the ocean shores around the Earth. Moreover, we don’t realize how valuable and necessary they really are.
In a new study published today in Nature Communicationswe made the first global estimate of the economic value of kelp forests – showing that they provide hundreds of billions of dollars in value to people around the world.
A human history of kelp
Along the Pacific, kelp harvesting has long played an important role in Asian societies. In Japan, seaweed was one of the marine products that people could use to pay taxes, according to a law book from the year 701.
In medieval Europe, kelp was used to fertilize the soil and increase crop yields, to treat cropand was used to strengthen building materials for centuries. In the 21st century, kelp forests have grown into the main source of alginatea common food and a medical additive.
And during this time, kelps have supported teeming ecosystems and important fishing of abalone, lobsters and many different types of fish. Due to their prolific productivity, kelp forests remove carbon from the atmosphereexhales oxygen and helps reduce nutrient pollution in our oceans.
A maritime marvel, hidden kelp forests dotted around almost a third of our world’s coastlines and are within 50 km of 740 million people. If you live in London, Tokyo, New York, Vancouver, Santiago, Cape Town, Los Angeles or Lisbon, you have one of these ecosystems on your doorstep.
Yet they are often forgotten or misunderstood. People are often not even aware of a kelp forest, and if they are, they may be most familiar with a pile of rotting seaweed on the beach after a storm.
Andrew b. Stowe/Shutterstock
This decoupling has real world implications. Despite sitting next to and probably covering some of the largest research centers in the world more seabed than any other biotic habitatresearch and conservation of kelp forests terribly behind other ecosystems.
This knowledge gap hinders much-needed action and conservation. Indoor kelp populations Northern California, Tasmaniaand the Salian Sea have all but disappeared in living memory. There have been kelp populations elsewhere continuously falling in the past 50 years.
What we value and how we value it is actually quite a complicated process. And despite the fact that we make value judgments over and over again every day, we have a very poor understanding of the value of something if it doesn’t have a price tag on it.
Our natural world is perhaps the ultimate provider of value – everything we do in our societies is ultimately connected to nature, ecosystems and a healthy planet. But because these processes and benefits happen with or without humans, they are often taken for granted.
Andrew Dawes/Unsplash
So, what is the “value” of a kelp forest?
Our research has brought together data from all oceans to provide a global estimate of the economic value of kelp forest ecosystems. Looking at six major genera of kelp – Macrocystis, Nereocystis, Laminaria, Sakharina, EckloniaAnd classes — and the potential economic value of the fisheries they support, the carbon they take from the atmosphere and the nutrient pollution they remove from the water, we found that kelp forests are valued at $500 billion a year.
The highest of these values was the removal of excess nitrogen from the water, causing algal blooms, reduced water quality and eventually oxygen-poor dead zones.
A close second was fishing values - kelp forests support some of our most iconic fisheries, including lobster and abalone.
Finally, despite the fact that the carbon sequestration of kelp forests was found to be comparable to that of other terrestrial and marine ecosystems, the economic value was much lower, as society has not yet put a high price on carbon. This finding suggests that carbon credits may not be an economic driver for kelp conservation, but that kelp forests still play an important role in the blue carbon cycle.
John Turnbull/Flickr, CC BY-NC-SA
The future of kelp
When nature is treated as a freebie, where we can take what we want and not pay for the damage, this attitude has direct consequences; people and the environment suffer.
First, it can mean that people and the government don’t see the value of protecting and restoring ecosystems. Second, development projects can destroy nature without compensating for that damage.
Finally, it leads to poor management. How can we manage something if we can’t quantify it? Imagine not knowing where your bank account was, or how much money was in it.
The battle to save our kelp forests has only just begun and we need more action to protect these intrinsically and economically valuable marine ecosystems.
That’s why researchers like me started the non-profit organization Kelp Forest Allianceand now have the Kelp Forest Challengea global call to protect and restore 4 million hectares of kelp forest by 2040. This is a call to governments to keep their commitments to the Kunming-Montreal Global Biodiversity Framework and act now to save these ecosystems and #HelpTheKelp.
Read more: Whether you’re a snorkeler or CEO, you can help save our vital kelp forests
