The Seaweed Food Revolution May Begin with a Name Change

While food scarcity and food security are two concerns that sadly remain firmly embedded in world affairs, a crop cultivated by humans for thousands of years may soon help alleviate both—precious fresh water not required. 

Macroalgae, more commonly known as seaweed, is quickly expanding globally as a sustainable crop low in its environmental footprint, high in nutrients, and applicable across a wide variety of industries. In fact, according to NOAA, seaweed farming is now the fastest growing aquaculture sector in the U.S., with "with dozens of farms in waters in New England, the Pacific Northwest, and Alaska and more in production."

Globally, seaweed cultivation has grown from from 34.7 thousand tonnes to 34.7 million tonnes between 1950 and 2019. This dramatic uptick reflects its use in everything from cosmetics and toothpaste to alternative plastics like biodegradable packaging and drinking straws. Increasingly, however, it’s also playing a growing role in helping to feed the world.

"When it comes to the ocean, we are still hunter-gatherers," Vincent Doumeizel, a senior advisor on ocean-based solutions at the UN Global Compact and author of the recent book "The Seaweed Revolution," said in a 2020 United Nations interview. "By farming just two percent of the ocean, we could provide enough protein to feed a world population of 12 billion people. Seaweed is extremely protein rich, low in fat, low in carbohydrates, and rich in vitamins, zinc and iron."

From 'Seaweed' to 'Sea Forest'

To truly appreciate the rich diversity and bounty of seaweed, Doumeizel believes that we should globally follow Norway’s example and instead refer to it as a "sea forest." Speaking at the Hay Festival in Wales, the author said this re-branding would be more appropriate "because we would understand that we need to protect and preserve them as we do with all the land forests."

Nearly 12,000 species of seaweed have been catalogued, all of which are edible, but with some more nutritious and palatable than others. There are three groups—red, green, and brown—with the latter encompassing sea kelp, the largest and most common type associated with massive underwater sea forests. Unlike land-based forestation efforts, "seaforestation" requires no fertilization, fresh water, or careful considerations of other competing food production interests. Coastal ecosystems also capture 20 times more carbon per acre than land forests, making them a critical defense against ocean acidification.

And then there’s the massive benefit of potentially feeding the world’s livestock just a tiny bit of seaweed each day, an incredible breakthrough that almost sounds too good to be true. 

"If livestock were fed on seaweed-based foodstuffs, rather than soy, methane emissions could be cut by 90 percent, and improve digestion whilst boosting the animals’ immune systems, which reduces the need for antibiotics," Doumeizel said. "This is already happening in some countries, such as Scotland and Iceland."

In Sweden, a startup called Volta Greentech recently announced plans to build one of the world’s largest seaweed production facilities to specifically address global emissions from livestock. When cows are fed just 100 grams of a supplement derived from the company’s sustainably produced red seaweed (Asparagopsis taxiformis), the methane gas produced in their intestines is reduced by up to 80 percent.

A 2021 UC Davis study found no difference in either the taste of beef or the milk produced by cattle when fed a diet that included seaweed. With livestock responsible for nearly 15% of all global carbon emissions, cutting this to a fraction would be a huge win in the fight against climate change.

"This could help farmers sustainably produce the beef and dairy products we need to feed the world," study co-author Breanna Roque said in a statement. 

Feeding the World, Lifting Communities

In addition to providing a nutritious supplement to help those hit by food scarcity crises, seaweed farming is also being championed as a boon for coastal communities, in particular for those where fishing is in decline. In places such as the U.S., however, where regulatory red tape has slowed the deployment of seaweed farming, politics and a perceived "broken permitting" process must first be ironed out. 

"We really were motivated to grow a business that could provide a market for kelp farmers and harvesters," Liz Heifetz, whose Alaska-based Barnacle Foods uses kelp to make products such as salsas and hot sauce. "It's not a cultural norm to have seaweed on our plates in America, but there would be a big upside if that were to happen here."

With world population estimates by mid-century targeting nearly 10 billion people, a solution as sustainable, nutritious, versatile, and easy to grow as seaweed just makes strategic sense. All that’s needed is a global effort to make seaforestation a key part of the solution.

"When you look at how we are going to feed the world population by 2050 in a way that doesn’t harm the environment, there is only one pathway," Carlos Duarte, a researcher and professor in biological oceanography and marine ecology told Time. "To scale up seaweed farming."