How Nimba Islanders are restoring coral reefs

Looking out over the Indian Ocean from Nimba Island now, it’s hard to believe that just three years ago, the stunning coral reefs surrounding Tanzania’s Zanzibar archipelago were dying.

Under the threat of climate change, overfishing and other human activities, islanders face the prospect of losing their livelihoods and being relocated entirely.

In an effort to save the colorful oval-shaped coral reef, which is about 7 kilometers (4.3 miles) in length quite close to the coast, communities on the small island have implemented a conservation project that has successfully restored some of the reef that had been lost.

The initiative also aims to protect coral reefs, world-famous for their beauty, in other ways.

The water is so clear that the coral reef, located 10 m (32 ft) below the surface, seems almost within reach.

But a few years ago, locals began to notice how stressed the corals were—due in part to rising sea temperatures caused by climate change.

Coral may look like a plant, but it’s an animal – actually a variety of tiny organisms called polyps. They grow very slowly, forming a hard shell by extracting salt from seawater, which then fuses together to form what’s called a colony.

Coral reefs are sometimes called “rainforests of the ocean” because they create ecosystems that support a variety of marine life.

But when water temperatures are a few degrees warmer than normal, corals expel the brightly colored algae that live in them and provide nutrients. When the algae leaves, corals fade, bleach and eventually die.

Explosives used by fishermen also kill the coral, and a large number of unregulated tourist boats and divers also cause damage to the reef.

Mnemba Island fishmonger Juma Mshindan said it was clear something was wrong: “There was a significant difference between the availability of fish before and now. In the past, fish was plentiful.

Sustainable travel group &Beyond and non-profit Africa Foundation began working with islanders in September 2021 to help address some of these issues.

Underwater nurseries are created using steel mesh tables where coral fragments are grown and then replanted on the reef.

They are cared for and nurtured by local divers trained as conservation rangers.

It takes about two to three months for the coral colonies to form and then rangers bring them to the reef.

Results so far are encouraging, with 80% coverage of the so-called “house reefs” surrounding the islands restored.

“It’s like they grew up on their own,” said conservation ranger Hija Uledi.

“We’ve restored the reefs and you can’t tell the difference. There are fish around them now. Great work, lots of species to see.

Conservationists also built artificial reefs – steel and stone structures – placed about 3 kilometers off the island, where conservation rangers planted new coral growth from nurseries.

These are designed to help replenish marine life – which benefits fishermen, but they also become a destination for snorkelers and divers.

Dr Camila Floros, chief scientist of the Africa Foundation’s Oceans Without Borders programme, said the ongoing restoration program was taking great care to use the right materials – learning from past mistakes around the world.

“When artificial reefs were in their infancy, people were using the wrong materials, like tires, to try and build them. It wasn’t the right way,” she said.

Dr. Floros acknowledged that the success of the redevelopment work around Nimba Island was due to the support of the local community.

“Whenever we have new initiatives, we discuss them with them and get their support,” she said.

Atuwa Omar is one of the local residents involved in the restoration work. Before working as a conservation ranger, the 24-year-old had been caring for young children at home.

“Working as a ranger on the Mnemba Island project not only allows me to provide food for my family, but also supports my son’s education,” she said.

Although Ms Omar admitted it was not easy for her as she was the only woman involved in the scheme.

She faces some conservative attitudes that don’t want women to participate, but she says the challenges are worth it.

Conservation groups have been working closely with local authorities, and the government of Tanzania’s semi-autonomous region of Zanzibar designated the sea around Mnemba a protected area in 2022.

This means action can now be taken to limit the damage caused by tourists and fishermen.

Bakari Jaha, coordinator of the Zanzibar Africa Foundation, noted that the atoll has been visited by a large number of tourists in the past.

“Initially, the area faced huge pressure from tourism, with 200 boats carrying at least 400 guests into this area of ​​only 200 square meters,” he said.

“To protect the area, the government, together with &Beyond and the Africa Foundation, has decided to limit the number of visitors to 80 people.”

Visitors used to pay a $3 (£2.40) fee – this has now increased to $25.

“This approach not only enhances environmental protection but also increases income,” Mr Jha said.

Fishing around the atoll has also been suspended as restoration work is underway.

“We are seeing positive changes. Illegal practices such as the use of dynamite have decreased, and fishermen are more aware of sustainable fishing methods.

The Zanzibar government says it is encouraged by the success of the Mnemba restoration program and hopes to expand it to other threatened areas.

“The government has identified 14 areas where coral reefs are undamaged and others where coral is damaged and we are planning to protect them,” said Dr. Makame Omar Makame, director of the Zanzibar Maritime Authority.

“We have placed buoys so people can be careful and understand that fishing is not allowed in this area.”

The pressures on Zanzibar’s coral reefs mirror the threats facing coral reefs around the world. Those involved in the Mnemba project say that while they can’t stop the ocean currents from warming, they hope their efforts can help other threatened areas.

“The relationship between the ocean and corals is critical to ocean health. We are witnessing the regeneration of corals, even at great depths,” Mr Jha said.

“We are allowing sea conditions to restore the reef to its original state.”