Kelp forest near Channel Islands, California
Shutterstock/Ethan Daniels
Kelp forests provide an estimated $500 billion in value to the world and absorb 4.5 million tons of carbon dioxide from seawater each year. Most of kelp’s economic benefits come from creating habitat for fish and sequestering nitrogen and phosphorus.
As with terrestrial forests, the climatic benefits of kelp forests are numerous. Towering brown algae provide habitat for marine life, protect coastal areas from storms, and sequester greenhouse gases as they grow. However, some kelp forests, such as those off the coast of California, are being damaged by pollution, human development, and overdose of hungry herbivores like sea urchins.
Aaron Eger and his colleagues at the University of New South Wales, Australia, examined the economic and ecological benefits of different types of kelp in different industries to estimate the value that kelp forests bring to the global economy. . They limited their assessment to his six genera of kelp that commonly form these forests.
The researchers started by evaluating the benefits kelp brings to commercial fisheries. Kelp is home to about 1,500 species, many of which are harvested commercially. We then estimated the amount of nitrogen, carbon, and phosphorus that kelp absorbs from the ocean. Large amounts of nitrogen and phosphorus from agricultural wastewater can lead to harmful algal blooms, making it particularly expensive to remove nitrogen from water using current technologies.
“Like land plants, [kelp forests] It absorbs nutrients, it absorbs carbon dioxide, and it uses light to promote growth,” Egger says. By examining the amount of each compound stored in plant tissues, we were able to determine how much kelp was sequestering.
They found that kelp forests generate a potential value of $465 billion to $562 billion annually worldwide. This is largely due to commercial fish support and removal of harmful chemicals. As part of the evaluation, the team found that kelp forests absorb about 4.5 million tons of carbon dioxide each year, highlighting kelp’s potential as a ‘blue carbon’ sponge.
Thomas Wernberg of the University of Western Australia said, “This is a very important paper as it is the first attempt to assess some of the most important ecosystem services from kelp forests. The next step, he said, would be to include more kelp species and assess broader benefits, such as kelp’s cultural importance to indigenous communities.
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