Seaweed Can Cure Climate Change, Who Knew?

You read that right. Seaweed (aka kelp) can indeed help to prevent the destructive effects of climate change. In fact, it benefits pretty much every aspect of the world's natural environment.

The earth has been warning us about the disastrous impacts that climate change can bring to life on our planet with events such as Hurricane Florence and the Thomas Fire. Climate scientists have been telling us for years that anthropogenic activities producing greenhouse gas emissions are the largest contributor to the rapid deterioration of our ecosystems. As we have all heard before, it is necessary to dramatically reduce the amount of carbon in the atmosphere in order to solve this impending issue. Most of the time we look to forests for the trees and plants to suck up all of our carbon emissions; however, forests are extremely vulnerable to deforestation for new developments in land use. Oceans also help to absorb carbon emissions and can take about 25% of all CO2 out of the atmosphere. But now the oceans are taking in too much CO2, and it is leading to ocean acidification, a process that makes the pH of the oceans more acidic killing corals and many other marine species that depend on them. Luckily, kelp is capable of sequestering (absorbing) an huge amount of carbon from the atmosphere, and it does it just because it wants to. Kelp has the ability to absorb nearly 5 times as much carbon emissions that terrestrial plants can and more than mangroves, salt marshes, and eelgrass can combined! This means that seaweed farms can provide an enormous carbon sink to help flight the effects of climate change and ocean acidification while simultaneously avoiding the impacts of deforestation on land.

How kelp creates a carbon sink (Zucker 2019. Adapted from Krause-Jensen & Duarte 2016)

Seaweed can also eat up other nutrients such as nitrogen and phosphorous that, in large quantities, can deplete oxygen levels in the ocean leading to large, deadly algal blooms. These nutrients enter the oceans through stormwater runoff from towns, cities, and farmlands and cause a loss of biodiversity in local coastal areas where the nutrients are heavily concentrated. Placing seaweed farms in strategic locations where these nutrient levels run excessively high would help to lower pollution levels and aid in restoring the natural ecosystems in that region. To make things even better, kelp doesn't even need any other resources such as fertilizer, fresh water, or protection like fencing. It simply thrives off of absorbing these nutrients and takes next to no management meaning that the energy efficiency of the practice is far greater than any sort of terrestrial agriculture.

Example of polluted runoff in coastal community (Joshua Stevens NASA)

Also, we can't forget that kelp forests already provide a natural habitat for a large amount of marine species to thrive in. Invertebrates such as sea stars, shrimp, and crabs feed on the algae and micro-debris within kelp forests. A multitude of fish species live in the ecosystem and provide a valuable resource to fishing communities. Seals and sea otters find refuge from sharks and other predators in the forests and eat sea urchins which can destroy kelp forests if they are left uncontrolled by these marine mammals. Birds like egrets, great blue herons, and starlings use the habitat as a natural feeding trough eating invertebrates, fish, and insects. Whales have even been found within forests when migrating in order to avoid potential predators like killer whales. Seaweed farms imitate this diverse natural ecosystem for hundreds of species to find a home in, and can therefore heavily benefit the ecological stability of the location.

Seaweed farming is full of environmental benefits and provides valuable ecosystem services to coastal communities that use it. With the industry being so new, there's no reason to not hop on board and start helping the climate and your local community. To get a more in-depth and visual concept of the environmental benefits that kelp aquaculture can bring watch this video produced by Lucy Biggers with Now This.