Teach a man to farm seaweed, he’ll eat even if fisheries collapse

[Senegal] When Thierno Mbengue walks down the main street leading to the village of Ngor, he calls out a greeting to almost everyone he passes. He seems to know everyone’s name, and he asks them about their jobs. When Mbengue, 41, spies a certain young boy walking alone, he takes him by the hand and leads him in the other direction; it is his nephew, and the boy is late for school. Mbengue and his family have lived here for generations, on this corner of the Cap-Vert peninsula that also holds Senegal’s capital city, Dakar.

Today, the Ngor area is known for its fancy villas and well-heeled foreigners who like the proximity to the ocean. But at the center, in the village, most houses are reached via narrow, sandy pedestrian passageways built long before there were cars and paved roads, long before the city of Dakar expanded around it, clogging the entire peninsula. Mbengue and the generations of Mbengues before him lived in this village, where they all had the same profession. They were fishers.

Their methods have changed over time; the previous generation fished with lines and nets, but most fishers in Ngor today fish by free diving into the ocean with spear guns. “It’s like you are a hunter,” said Mbengue. “If you see a fish, you shoot it.” Ngor’s fishers specialize in grouper, dorade, and shellfish, selling most of their catch to the expensive restaurants and hotels that hug the shores of the city.

More than a decade ago, Mbengue said, some buyers started asking for something different: They wanted a specific kind of red seaweed, Meristotheca senegalensis, that flourishes in Ngor’s bay and during a certain time of year washes up on the sand everywhere, in wave after unrelenting wave. But what washes up is just a portion of what can be found in the sea. So Mbengue started diving for that too, noticing where it grew in large quantities. “Wherever you find rocks, there will be seaweed,” he said.

Diving for seaweed was just the beginning, though; now, Mbengue and some other fishers want to farm it.

When the seaweed season arrives, and if there is a buyer, the whole village of Ngor mobilizes to collect the stuff—not just divers like Mbengue but also children and market women who gather seaweed from the sand. “You have to wake up early in the morning to do it, because if you wait other people will collect all of the seaweed,” said Mbengue. He says that he works with his brothers to dive for the seaweed in a group. That way they can maximize their efforts and take back more to the shore. But wild seaweed, like most wild things, comes in unpredictable quantities. When Mbengue heard that you could farm it, he understood the advantages right away.

The conceptual road to seaweed farming began not in the ocean but in the laboratory. Mbengue first learned about seaweed farming just a couple of years ago from Moussa Yagame Bodian, a plant biologist at Dakar’s Cheikh Anta Diop University. In Bodian’s laboratory, the counters are covered with beakers full of what looks like swamp water—an experiment of a colleague who studies microscopic algae.

Dried red tosaka seaweed, often used in salads. (Photo: Getty Images)
Dried red tosaka seaweed, often used in salads. (Photo: Getty Images)

For his part, Bodian has long been interested in macroalgae, the kinds that grow in the ocean like weeds and whose forms are as numerous as can be imagined: some with broad leaves like lettuce and others full of fine, stringy tendrils. He says that he has never heard of his Senegalese ancestors using seaweed in their culinary traditions. However, he likes to remind people here that seaweed is versatile and can be used in cosmetics or as a food additive or, yes, eaten directly for its health benefits and taste. Meristotheca senegalensis, for example, was first harvested here to make carrageenan, an additive that shows up in everything from soy milk to toothpaste. But a second wave of exporters started sending it to Japan where it is known as tosaka nori and eaten like salad.

Bodian said he first started studying seaweed in the mid to late 1990s, just after a long period of expansion in fishing industry. “When we got interested in seaweed, it was a time when the fishing industry was just starting to suffer a little,” he said. “Before, there was an enormous amount of fish. No one thought that there could ever be a problem in terms of biomass. We just couldn’t imagine it. But it has happened.”

Scientists say the fishery here peaked during the late 1990s, worn out after decades of ever-increasing catches from the legal industrial trawlers and illegal pirate fishing boats working offshore, plus the tens of thousands of small-scale fishers working, well, everywhere. At the same time, a series of environmental challenges sprung up: Cities along the littoral expanded, and so did the pollution authorities discharged directly into the ocean; trawlers disturbed sensitive ecosystems; mangroves were cut down; and coastlines eroded. The fishing industry in Senegal entered a period of slow decline, a period it is still in today despite all the efforts to rehabilitate it. That means not everyone who wants to can make a living from the ocean as they once did.

Mbengue’s older brother Oumar said he has not gone out fishing for more than six months. There are too many disputes between those fishers who use a line, as he does, and divers like his younger brothers. And sometimes, pretty often even, the fish he catches might not be worth the money he used to buy gas for the outboard motor. “I am almost ready to quit,” he told me.

What is happening in Senegal is a part of a global downward trend for marine fisheries. The U.N. Food and Agriculture Organization estimates that worldwide, fishers are harvesting nearly 30 percent of fish stocks at levels so unsustainable that they may eventually lead to collapse. In parts of West Africa, the specter of collapse is an issue that hits people both in their pocketbooks and on their plates. Fish provide 44 percent of the animal protein that people in Senegal eat, because it has traditionally been both cheap and abundant. And that wealth of fish has benefitted more than just the people of coastal Senegal; traders come from as far away as Mali and Burkina Faso to export fish to their landlocked countries.

For those fishers who do want to quit or even just fish less, Bodian thinks seaweed could be part of the solution. “We think that seaweed collection and, eventually, seaweed farming could help coastal communities have an alternative source of revenue,” he said.

Massata Ndao has been leading a project to evaluate the potential of Senegal’s seaweed resources, a project that has been sponsored by the Senegalese government with financing from the Japan International Cooperation Agency. He said that before the first seaweed prospectors came, no one gave algae much thought. “The fishermen and the women who sell and clean fish, they saw the seaweed, but they didn’t know that they could do anything with it,” he said. His project is cataloging all the existing species of seaweed in Senegal and evaluating their commercial potential. “There is certainly some money to earn with this.”

Oumar and Thierno Mbengue are both exploring the idea and are part of a group of other fishers and divers from Ngor, some students in fishery science, and Bodian himself who have formed a seaweed farming collective. Their inaugural season in 2014 was to test their farming methods in the bay of Ngor.

Boats surround Ngor beach Dakar, Senegal, Africa
Boats surround Ngor beach Dakar, Senegal, Africa

“For seaweed, farming it in general is not so hard, but the problem is getting a pure sample and making sure that when you harvest it, you only get the species that you planted,” said Bodian. Years ago, when he first started trying to explore the idea of farming seaweed, he began with another species, Hypnea musciformis, which has high levels of carrageenan. But the algae’s hair-like branches have a tendency to wrap themselves around any foreign object that comes their way. So the final product was full of impurities—shells, nets, trash, and other algae. When he switched to Meristotheca senegalensis, its bigger leaves were much easier to manage.

The process is simple: Meristotheca senegalensis cuttings are attached to a cord, and Mbengue and the other divers anchor the cord at the chosen spot, about 40 feet down in the water column. After that, like all good farmers, they wait. Nature does most of the work, and they just survey it from time to time, checking on its growth. “The seaweed grows fast,” said Mbengue. “We harvest it by pruning the plants back, but they will grow to a good size again in about 15 days.” As an extra benefit, wherever Meristotheca senegalensis grows, abalone follows. A patch of seaweed can serve as habitat for small fish and shellfish and thus as a building block for a regenerating ocean. In that way, it can build biodiversity at the same time that it helps fishers regain ground economically. Abalone, for example, fetches a high price locally and an even higher price in China and other parts of Asia, where enterprising merchants often send it.

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