Kelp Forests: Unsung Hero for Combatting Climate Change, in partnership with Akua

This year’s Oscars finally brought kelp to the mainstage - well, unintentionally. Nominee for ‘Best Documentary Feature,’ My Octopus Teacher captures the unique relationship between filmmaker Craig Foster and a wild octopus in a South African kelp forest. While the octopus is the star of the film, the true unsung hero is the kelp forest that enables and supports this friendship. Foster describes the kelp forest that he swims in every day as “a giant underwater brain operating over millions of years...and it just keeps everything in balance.” In addition to creating beautiful habitats and nurturing marine species of all shapes and sizes, the kelp forest is a key player in battling climate change. We at Plant People have partnered with AKUA - a company producing healthy, sustainable foods made from ocean-farmed kelp - to explore the benefits of kelp in naturally sequestering carbon dioxide and how you can join this growing movement. 

More formally known as Phaeophyceae, kelp is a brown algae and member of the macroalgae family. Kelp forests grow along the coastlines of every continent except Antarctica and can reach heights of 175 feet (to put this into perspective, this is about equal to a three story building!). While coastal ecosystems sequester up to 20 times more carbon per acre than land forests through photosynthesis, kelp is unique due to where it grows. When marine plants like mangroves and seagrass die, their leaves, stems and roots get buried in the soil for years before breaking down and releasing carbon dioxide. However, due to how close these marine plants grow to the shore, their decaying parts get submerged in places that are easily disturbed by human activity, storms, and runoff. As a result, the carbon dioxide that these plants have captured and stored typically is released back into the atmosphere sooner than it should be, which completely reverses their contribution to carbon sequestration. 

Enter kelp and its journey through the ocean. Kelp attracts to rocky coastlines, and we should be thankful for this macroalgae calling these types of environments home. Due to the rough surroundings of these coastlines, kelp is less likely to be buried along the shore. Instead, pieces of kelp travel to the deep sea due to gas-filled bladders that allow these plants to float for long distances. Once the bubble bursts, kelp sinks to the ocean floor, where the carbon is sequestered indefinitely. Dorte Krause-Jensen, a professor of marine ecology at Aarhus University in Denmark, reveals, “If the algae reaches below the 1,000-meter horizon, it is locked away from exchange with the atmosphere over extended time scales, and can be considered permanently sequestered.” 

The impact of kelp burying itself in the deep, dark ocean floor is immense. A recent paper from Nature Geosciences found that around 200 million tons of carbon dioxide are being sequestered by macroalgae every year, which is about equal to ⅔ of the entire United Kingdom’s annual carbon dioxide emissions. Unfortunately, kelp forests are getting destroyed at alarming rates due to rising water temperatures, pollution, and fishing. For instance, a marine heat wave wiped out more than 90 percent of the kelp growing along California's north coast. However, environmental activists and companies like AKUA are fighting to save kelp for the future of the planet. 

One popular strategy used is supporting kelp farming. Kelp farming usually takes place in shallow waters where floating cultivating lines house and grow kelp. In layman's terms, kelp farming is a zero-input crop that requires no fresh water, no fertilizer, no feed, and no arid land to grow. If just nine percent of the ocean were covered by these seaweed farms, kelp would capture 19 gigatonnes of carbon dioxide. In addition to naturally filtering carbon dioxide and nitrogen from the ocean water, kelp has created new jobs for coastal communities. The benefits are endless! 

As Foster alludes to in the end of the film My Octopus Teacher, kelp is a natural resource that we need to treasure. He co-founded the Sea Change Project, a community of divers who are dedicated to the protection of the kelp forest. If you live near a coastline, search to see if there is a local kelp restoration project near you. Or, call your state representative to ask for no fishing zones and stricter policy around the chemicals used and dumped in farming and manufacturing. While kelp is finally getting recognized as a key player in carbon sequestration, these marine plants cannot be the only solution to global warming. As we kick off Earth Month, we need to continue to explore how we can decrease fossil fuels, destruction of forests, and more. Kelp is just one important way we can help create a happy and healthier planet.