giant underwater algae provide us with unsuspected services

When we talk about kelp forests, we are talking about these fields of kelp (or kelp in English), brown algae found on a third of the world’s coastlines. These kelp forests can reach 20 to 30 meters in height, and play a very important ecological role. A team from Australia’s University of New South Wales has calculated that the world’s kelp forests produce the equivalent of $500 billion in wealth a year. This is more than the pension budget in France. It is a richness provided three times greater than what we thought so far.

These 500 billion dollars correspond to the price of the services they render to us. For example, by providing nutrients to fish and shellfish, they provide important resources for fishing. They are also the main habitat areas for at least 1,000 underwater species. These underwater kelp forests also absorb nearly five megatons of CO2, putting them on par with terrestrial forests. They help us remove tons of excess nitrogen that enters the oceans via sewage or agricultural runoff.

Threatened by global warming

In fact, it does not solve anything in terms of biodiversity. But here, the Australian researchers want above all to alert and draw attention to these algal forests, because they are threatened by global warming. Their surface has been shrinking for 50 years, and these scientists believe that we do not talk about it enough. We talk much more often about the importance of protecting corals or terrestrial forests, and yet these algal forests play an equally important role.

Scientists therefore appeal to the government of the world to preserve them. Some have even launched the Kelp forest challenge, (the challenge to replant kelp forests) because these researchers have calculated that one million hectares of kelp forest should be planted by 2040, if we want to preserve the ocean ecosystems.