Around the world, coral reefs are in danger of disappearing. On the East African island of Zanzibar, however, the organisation marine cultures is working to reforest the damaged underwater ecosystems. It’s a race against time.

The fishing village of Jambiani was once considered an insider’s tip among visitors to the southeast coast of Zanzibar. It is an hour’s drive from the capital Stone Town and stretches for several kilometers along the coast. 

Until a few years, apart from a few travelers  from Europe, only few foreigners strayed here. It has no proper village center with a market like the popular tourist destinations on the north coast. In a whitewashed stone house 150 meters from the beach, behind one of the oldest hotel complexes in the village, is the office of marine cultures. 

Adjacent to it, is a small dive shop, and further ahead, in front of the hotel’s entrance gate, a kiosk selling water, nuts and bananas. In the backyard of the association’s office, coral farmers Abdi Mjaka Haji and Ali Pandu Suleiman – called Tabu – discuss today’s dive with project manager Ali Mahmudi before putting on their thick wetsuits.

From the house across the street, a radio station in the local language, Swahili, blares into the morning silence. It is eight o’clock in the morning, and the equatorial sun is already baking the earth. Ali wishes his colleagues good luck and sits down at his desk under the whirring fan. Meanwhile Abdi and Tabu walk with the heavy oxygen tanks on the back through the alley past a few houses in the direction of the beach.

They greet a little girl wearing a pink headscarf. She looks at them curiously. Across an open, somewhat run-down beach plot, the few steps of the stone staircase up to the beach, Captain Hassan Ameir is already awaiting for  them in the knee-deep water.

 A little further away a group of young Maasai try to offer the early birds a trip or a pair of mirrored sunglasses. There is a typical tropical morning atmosphere in the Tanzanian paradise. But in this deceptive idyll, an environmental catastrophe is gradually unfolding: corals are dying – and with them the entire reef.

In Jambiani people depend on fish for making a livelihood

The underwater gardens off Zanzibar

Soon, the small motorboat carrying Abdi, Tabu and Hassan rushes out to a red buoy in just a few minutes. Beneath it, at a depth of six meters deep and pleasantly cool, is the coral farm of marine cultures.

On a dozen steel beds, corals grow, strictly grouped according to species and genotypes above which hang sponges that are also cultivated by the association.

The underwater gardeners Abdi and Tabu dive four times a week to care for the coral seedlings. The task is to nurture the small coral babies and to clean them. Various pests hinder their growth or deprive them of all nourishment, such as the brown

algae, for example. 

The changing tides sometimes cause strong currents in the lagoon channel, so that other materials get caught in the corals, such as algae, sea grasses or even plastic bags.

Mostly with him on the dives is Christian Vaterlaus, founder of marine cultures. The man in his mid-sixties left Switzerland for Zanzibar 15 years ago together with his wife Connie Sacchi and built up the organization with local and international partners, with the aim of offering the population an alternative to the poorly paid cultivation of seaweed and fishing, which is no longer profitable..

The creeping death of corals

Corals are accustomed to a certain temperature range between five and six degrees. If this is exceeded, the small algae, which live in symbiosis with the polyps, produce too few nutrients, which stresses the coral animals, causing them to reject the symbionts. This leads to bleaching and, and with a prolonged increase in temperature, death.

As a result, brown algae overgrow the skeletons, where corals will never grow again in the future. Thus their spread along the East African coast has decreased by about 25 percent.

If corals were to disappear forever, the consequences would be catastrophic, as they provide habitat and food for a quarter of the marine ecosystem, as well as providing protection for the coasts from tidal waves. And they are also the economic backbone for the fishing and tourism sectors.

Cloning in the race against the crisis

Corals actually all reproduce simultaneously once a year: Each time after the hot spell following a full moon, polyps release eggs and sperm, which then come together in the surrounding water. But about ten years ago, researchers were able to prove for the first time that corals do not only reproduce sexually, but they also clone themselves. Both types of reproduction are now being used by marine biologists for coral reforestation.

Marine cultures has opted for cloning. This is because it is far less expensive and much less complicated than the cultivation of resilient corals in jars, and it is also easier to learn for non-professionals. Above all, the latter was important to Christian; he did not want only graduated biotechnologists to be there to practice their craft.

In the meantime, the four-member team releases between 8000 and 10000 coral seedlings annually. However, reef reforestation is not a quick fix, nor is it the solution to the climate crisis. It only helps species of coral to survive in the long term and to adapt to the higher water temperatures.

“But it’s not just ocean warming that threatens this sensitive system. Overfishing of the lagoons is also a problem, as there is a lack of capacity to monitor it in many places,” explains Christian. This particularly affects coastal dwellers who depend on fishing. Coastal fishing with permitted fishing methods would not affect the natural balance, Vaterlaus is convinced.

The way greater threat to the reefs is happening far off the coast: The partly illegal industrial deep- sea fishing is very efficient and there are no limits on the techniques and catch quotas.

In order for the reefs to survive, there is an urgent need for effective marine protection measures. But: “Up to now, there have been no locally anchored protection concepts, and if they do exist, there is a lack of enforcement,” explains Christian.

The coral farmers are planning the control dive to the coral farm

Difficult educational work

The marine cultures organization doesn’t just work in isolation in its own small underwater gardens, but is in constant exchange with researchers, and its work is scientifically supported.

Coral resilience is a relatively new topic in science, but due to the climate crisis, smaller organizations like Christian and Connie’s are compiling important data for research.

“We have people coming to us from all over the world who are interested in doing their own coral reforestation themselves, as well as other NGOs, scientists and journalists,” Christian explains. Currently his association has a project with another NGO, which is associated with an international hotel chain, that is developing a coral reforestation on the island of Mnemba. 

Christian and marine cultures have trained three more coral farmers for the organization, all three of them Zanzibari, who will work in the future as marine protection rangers for the island. They are trying to reforest the reef there, which is in a bad condition due to the daily snorkeling tourism.

Without sustainable fishing and protection from pollution, the ecological benefits of coral reforestation are minimal. It would be urgent that more investment in marine conservation was done. In 2014, therefore, the Zanzibar Coral Reef Monitoring Network was founded, consisting of a good dozen smaller organizations who have since been active at the grassroots level in Zanzibar in education and marine protection measures. 

Nevertheless, everything is progressing slowly. 

It is sometimes more difficult to convince the neighbor of their concept than to convince the international guests from the world of science or media, who visit them regularly, Christian explains. 

A year ago, for example, a Chinese television station portrayed the coral farm with the intention of having it broadcasted also on local television. Despite the improvement of the fisheries minister, the report has not yet been broadcasted. 

Dream job as a coral farmer?

Project leader Ali himself cannot yet dive. He often sits on the porch in front of the office and waits for his colleagues to return from their dives. Every now and then, unaccompanied cows and goats trot by scavenging for food from kitchen waste in open areas throughout the village. Otherwise there is little activity, except for a few motorcycles or cabs driving tourists to the beach hotel.

The Zanzibari is in his mid-twenties, studied on the Tanzanian mainland in Arusha and is the only one of his small group of students from Zanzibar who have found a permanent job after graduation. At least 14 percent of the inhabitants are unemployed, according to official statistics. 

The region is poor. Ali says he was simply lucky. He had known about marine cultures for some time because he lives next door to the office. “I hoped, even as a student, that I would find a job here later,” he says.

His father was a fisherman, but left the profession after the big coral bleaching event of 2016, because the sea no longer brought in enough catches. Now he works as a gardener. The former student remembers how, as a child, they used to wait for the fishing boats to arrive on the beach: “Children, here, take fish, it’s free,” the fishermen called out to them. Those days are long gone. 

Today the fish are supplied  to the hotels first, and there is hardly enough left for their own families, says Ali. Oftentimes, they survive on cassava and rice.

Tourism or no tourism – both are bad for the environment

Zanzibar is becoming an increasingly popular vacation destination, attracting several hundred thousand tourists each year. Many of the residents of Jambiani now work in tourism – as taxi drivers, hotel employees or tour guides for snorkeling excursions.

East Africa is one of the fastest growing regions in the world, and more people are attracted from up country to the coasts: Tanzania’s population grew between 2012 and 2016 from 44 to 50 million. As a result, the environmental impact has increased. Sanitary facilities are hardly ecological, wastewater often flows directly into the sea, and garbage is being burned in open land.

Thanks to a private initiative, there are regular beach cleaning activities to prevent the worst from happening. During the first phase of the pandemic, before Tanzania reopened its air traffic, all customers disappeared, and basically all hotel employees were on the street. The emergency drove the entire village out into the lagoon, and everyone went fishing.

Everything they could get their hands on was taken out. It became clear that the economic dependence on tourism is not sustainable: the Covid’s closure of all tourist infrastructure accelerated a development that had already begun before.

Snorkel tourism is growing along the East Coast of Zanzibar

More and more hotels

“The village has changed a lot,” Ali confirms. “When I was a child, there weren’t all these houses on the beach front. More and more locals sell their land to investors or private individuals from foreign countries.” 

The result: more and more hotels. And the vast majority of the qualified workers in the village are no longer Zanzibari, but from the mainland of Tanzania or neighboring Kenya.

With the increasing charter tourism, the island threatens to become an Ibiza in the Indian Ocean. The government writes sustainable tourism on its flag; it is to be hoped that this will be implemented. Not least for the sake of the reefs.

That the coral reefs off Zanzibar can still withstand the constant pressure from the climate crisis and the increase in tourism, at least for a while, Ali is convinced. That is why he also wants to learn to dive next year. “To finally see the coral farm himself,” he says with a smile.