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How farmers and seaweed can help tackle ocean pollution

Seaweed’s benefits as part of a superfood are well-sung but its potential to tackle the destabilization of the Earth’s natural nitrogen and phosphorous cycles deserve more attention.

Seaweed in water

The seaweed has the power to unlock farming potential. 

Farmers as a group don’t typically embrace change. Just ask Luis Lombana, CEO of Ficosterra, a Spanish marine biotechnology company that makes fertilizers from an unexpected source: seaweed.

"Whether you are in Spain or Mexico or the States, farmers are very slow to change the way they’ve been doing things traditionally, especially when you come to them with something so different as seaweed," Lombana said. "To some of them, it sounds a little like a joke. They look at you and say, ‘So my plants are going to taste like fish?’ It takes a lot of education." 

When it comes to ocean health, the work of convincing farmers to ditch their synthetic fertilizers can’t happen fast enough. And companies such as Ficosterra — which derives its name from ficos, the Greek word for algae, and terra, the Latin word for earth — believe seaweed can help transition farming back to the nature-based methods humankind used for millennia, before the invention of industrialized agriculture.

Natural fertilizers or "biostimulants" are part of a burgeoning seaweed industry in the West, driven more by the slippery superfood’s potential as a climate solution than by kids clamoring for seaweed snacks in their lunchboxes. 

Chock-full of vitamins, minerals and antioxidants, seaweed has been a staple of Asian diets and traditional medicine for centuries, and its various applications in food production and scientific research date back decades. More recently, though, marine algae has been hailed by scientists and others for its environmental benefits — particularly the C02 sequestration potential of seaweed aquaculture — spurring a boom in North American kelp farming. And a whole crop of western startups making climate-friendly algae-based products, including clothes, cosmetics, bioplastics and biofuels, have popped up.

But seaweed’s potential to help tackle one of the planet’s least recognized, and most urgent, ecological crises — the destabilization of the Earth’s natural nitrogen and phosphorous cycles — has garnered less attention. Excessive amounts of these nutrients, nitrogen in particular, are flowing into lakes, estuaries, bays and oceans across the globe, causing harmful algal blooms that wreak havoc on marine ecosystems and can be toxic to humans. Wastewater from overburdened urban septic systems and air pollution from burning fossil fuels contribute to nitrogen pollution, but often runoff of the synthetic fertilizers used in industrialized agriculture is the primary culprit. 

Seaweed’s potential as a solution to this crisis is two-fold, scientists and environmentalists say. Research has shown that offshore seaweed aquaculture can significantly reduce excess nitrogen flowing into coastal waters, while replacing synthetic fertilizers with biostimulants made from seaweed would reduce the amount of nitrogen entering the ocean from agricultural sources.

A silent killer on a massive scale 

Algal blooms happen naturally, but when excessive nutrients flow into coastal waters from upstream sources, it stimulates overgrowths that throw the whole system out of whack. Ocean dead zones, areas where these overgrowths consume so much oxygen that nothing else can live there, are one result of this imbalance — such as the massive one in the Gulf of Mexico, caused by nutrient pollution from the Mississippi River basin. The Gulf dead zone grew to 6,634 square miles this summer, an area larger than the state of Hawaii. 

Likewise, scientists have tied the foul-smelling sargassum blooms that have plagued beaches in the Caribbean and Mexico over the last decade, in part, to runoff from the agricultural industry that has laid waste to large swaths of the Amazon rainforest. And while the climate crisis gets most of the attention with regards to coral reefs, researchers in Florida have found that nitrogen-laden pollution — from poorly treated sewage and the synthetic fertilizers used on farms, lawns and golf courses — has played at least as much of a role as warming waters in the near extinction of coral in the Florida Keys. 

"Nitrogen is what’s driving all of these harmful algae blooms in Florida, the red tides, the brown tides, the blue-green algae … and the dying coral," Brian Lapointe, a research professor at Florida Atlantic University, who conducted the 30-year study on nutrient pollution and coral death, told GreenBiz. 

Take a look at the "nine planetary boundaries," the limits that scientists say humans must respect to keep the planet habitable, and you’ll see we’re already beyond the safe operating space for four of them: climate change; land-system change; biodiversity; and biogeochemical flows of phosphorus and nitrogen. In terms of biodiversity loss and excess nitrogen, we’re well into the high-risk zone. 

"But you just don’t hear a lot about it," Lapointe said. "You hear a lot about climate change and CO2, but not about nitrogen."  

Lapoint points out that in the case of coral reefs the two crises are intertwined, because nitrogen is a driver of reef biodiversity loss. Indeed, scientists are increasingly recognizing nitrogen as a threat to plant and animal species around the globe. 

Cultivating a circular solution 

Reducing the excess nutrients that cause algae blooms through seaweed aquaculture and biostimulants is either ironic or circular, depending on how you look at it. Either way, it amounts to algae saving the ocean from algae. 

More than 10,000 species of seaweed fall into three color classifications: red; brown; and green. Most seaweed production involves the cultivation of various types of red algae, which grows in warmer waters near the equator, and brown algae, such as kelp, which grows in the cooler waters to the north. 

Estimates vary on the size of the commercial seaweed market. One conservative estimate put it at $16.7 billion in 2020, with growth to $30.2 billion projected by 2025. The food industry comprises most of the market and is expected to be the main driver for growth; however, reports cite the cosmetics and personal care industry, and agricultural use — both as a fertilizer and in animal feed — as additional drivers.

This projected growth continues the trend of the past 50 years. Between 1969 and 2019, global seaweed production increased to 35.8 million metric tons from 2.2 million metric tons, according to a report from the UN’s Food and Agriculture Organization. Asia dominates the market with 97.4 percent of world production, but indications point to a rapid increase in European and North American cultivation, by both large corporations that have dabbled in seaweed for some time and startups founded on algae’s environmental promise. 

A handful of organizations are even trying to make use of harmful sargassum blooms in the Caribbean, by collecting the seaweed and turning some of it into products, including fertilizer. Startups such as SOS Carbon, based in the Dominican Republic, and C-Combinator, a U.S. company with operations in Puerto Rico and Mexico, are two of those. But much of this work remains in its early stages, because sargassum is tricky for a few reasons. Most important, the blooms contain unhealthy levels of arsenic and heavy metals that must be removed before it’s sprayed on plants or ingested by humans or animals. 

SOS Carbon, a startup born at MIT in 2018, has partners working on various products and aspires to use sargassum as a carbon sink, by sequestering the seaweed, along with the CO2 it’s absorbed, in the deep ocean. In the short-term, though, the company is focused on collection using its Littoral Collection Module, which mounts on any small boat and is designed to sweep up sargassum before it reaches shorelines. 

The birth of what is essentially a new industry doesn’t happen overnight, and investors don’t always have a lot of patience. 

In addition to the environmental damage, the blooms have hurt the Caribbean’s tourism industry and local fishers’ livelihoods. The Global Tourism Resilience and Crisis Management Center estimates that governments spent about $120 million in 2019 trying to clean Caribbean beaches, with limited success. This doesn’t include what hotels and resorts pay to clean up their private beachfronts, which owners estimate can cost a medium-size hotel $60,000 a year. 

SOS Carbon contracts with hotels in the Dominican Republic’s resort area of Punta Cana and hopes to quickly expand across the Caribbean. Through these contracts, it’s able to train local fishers how to use its collection module and as of now employs seven full time. 

"They just need a way to sustain themselves," said co-founder and CEO Andrés Bisonó León, a Dominican Republic native. "We’re bringing them in as formal employees and providing health insurance." 

Not your average startup

Although the outlook for the broader industry appears positive, the West’s seaweed revolution does face challenges. Securing suitable nearshore sites for cultivation and building the infrastructure for growing, transporting and processing seaweed takes time. We’re several years into a media love affair with seaweed that’s seen more than one "kelp is the new kale" headline, and a young crop of North American producers focused on food are just now seeing business take off

Then there’s the issue of money. The birth of what is essentially a new industry (outside of Asia anyway) doesn’t happen overnight, and investors don’t always have a lot of patience. 

"The first intentions of a lot of funds are positive," said Joost Wouters, cofounder of a Dutch startup called The Seaweed Company. "Unfortunately, a lot of funds, even if they claim to be circular and green, it’s still traditional, old-school capitalism. And that’s not always helpful, because we’re not here for a five-year exit. We’re not a software startup."

Like many of its peers, The Seaweed Company, founded in 2018, has a variety of projects and products in the works, but it is furthest along commercially with its brand of biostimulants and of seaweed-based animal feed. The same nutrients that benefit human health can also contribute to the healthy growth of farm animals. Researchers have even found that certain types of seaweed used as feed supplement for cattle can reduce methane emissions from cow farts. Biostimulants, meanwhile, have been shown to improve crop yields, by enhancing nutrient uptake, growth and stress tolerance. 

Like most environmental solutions found in nature, the use of seaweed in land-based farming and animal husbandry goes way back. In Europe, coastal communities from the Iberian Peninsula to the northern British Isles used seaweed to enrich infertile agricultural soils at least as far back as Roman times, researchers have found. 

Much of this knowledge was lost with industrialization, but some local traditions have continued, Wouters said.  

"Farmers in Ireland have used seaweed for centuries," he said. "The farmers we work with in Ireland know it works." 

Word of mouth helps. Pilot programs designed to transition farmers to nature-based practices often count on farmers teaching each other. This is the strategy Ficosterra uses on both sides of the Atlantic. The company in 2017 spun off from its parent Hispanagar, a 50-year-old producer of seaweed extracts for uses in food production and medical science. Three years later, it entered into a joint venture with Algas Marinas, a Mexican company dedicated to harvesting seaweed for agricultural uses, and formed Ficosterra América. 

"We usually work with a reference farmer, a reliable reference customer can convince other customers," Lombana said, adding that the company’s retention rate is 70 percent. "Once you get a customer, they’re very loyal." 

While it’s a start, given the urgency of the crisis, individual farmers changing their ways likely won’t be enough. As with climate change, government policy is needed to move things along. The good news is that governments have begun to acknowledge the crisis. In 2019, UN member states adopted the "Colombo Declaration," which aims to halve nitrogen waste by 2030. And because water nutrient pollution  — unlike global warming — is largely a localized problem, a lot of work can be done at the local, regional or national level. It won’t take all the countries in the world coming to an agreement to get started, just pockets of political will.   

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