The symbol of longevity and unique conservation.
Coral reefs are not very common or widespread around the ocean. But they are invaluable to the marine environment. Because even though they cover less than one percent of the ocean floor, coral reefs house more than twenty-five percent of all marine life. That says something about their importance and that is why the conservation work of Danir’s very own coral reef is so important in the marine ecosystem.

What is actually named Shungimbili Island is also referred to as Thanda Island, a name that came with the Olofsson family when they sought to build a resort on the island and create a paradise retreat. This would become a place for calm, tranquillity, and indescribable experiences, on land, at sea, and below the surface. Thanda, which means “love” or “to love” in Zulu, is also the name of the company that, among other things, runs Thanda Private Game Reserve in South Africa and is the group’s representative in the five-star hospitality and experience industry. So, you could say that Thanda Island is the experience and Shungimbili is the island.
When the Olofsson family took over the island, one of the requirements was to establish a marine nature reserve in the sea around Shungimbili. This is because the waters around the island, as well as around the neighbouring islands of Nyororo and Mbarakuni, have been severely abused over the years. The seabed, coral reefs and all marine life had suffered severe damage from destructive fishing methods such as dynamite fishing and drag netting. And already in 2007, long before construction on the island had begun, the area around these three islands was declared a marine nature reserve. It also received the highest possible level of protection, a so-called “no-take zone”, which means that no fishing is allowed within the reserve.
The responsibility and monitoring of the Shungimbili Marine Nature Reserve falls under and is run by the Mafia Island Marine Park. And since Thanda Island was completed and began operations in 2016, park rangers from Mafia Island Marine Park have been stationed on the island.
The protection of the marine environment has already begun to yield results, and the coral reef ecosystem is slowly recovering. First, the fish population has increased both in number and diversity. Since 2016, species such as the large and impressive eagle rays and giant groupers have returned to the reserve. A good sign that the work to recreate the reef is paying off.
Further evidence of Thanda’s serious commitment is that since 2017, they have their own marine biologist, Rianne Laan, based on the island. Rianne, originally from the Netherlands, earned her master’s degree in biology from Wageningen University, specialising in marine biology. During her final internship with the Reefolution Foundation in Kenya, she worked on coral reef restoration, which later brought her to Tanzania and Thanda Island. Her work focuses on monitoring the reefs in the island’s private marine reserve, educating guests, and taking them snorkelling on the reefs. She also runs a small reef restoration project and collaborates with Ropes of Hope on Mafia Island to share knowledge and experience, with the aim of expanding efforts in the region and making a real difference.
Coral reefs, the rainforests of the oceans
Coral reefs are living structures created mainly by stony corals, or Scleractinians. The small coral animals form colonies and secrete a calcareous skeleton that forms the basis of the coral reef. How a coral colony grows depends on which environmental factors, such as light, currents, sediments and waves, it is exposed to. Therefore, corals of the same species can look completely different depending on where they grow. This contributes to a fascinating diversity of shapes, colours and textures.
It is these physical structures that create habitats for hundreds of species. And because of their high biodiversity, coral reefs are often called the rainforests of the ocean. Although they cover less than one percent of the world’s ocean floor, they provide living conditions for more than 25 percent of all marine life. The reefs also provide natural coastal protection, and coastal communities are economically dependent on them for fishing and tourism.
Thanda’s efforts are paying off
Unfortunately, coral reefs worldwide are threatened by human impact. Locally, by mass tourism, destructive fishing methods and pollution. Globally, by climate change. Increasing sea temperatures and the acidification of the oceans mean big problems for coral reefs. And the reefs at Shungimbili are no exception. You could say they have had to start from scratch. Devastating dynamite fishing and drag netting left large sections of the reefs in a pile of rubble. Since it became a marine nature reserve in 2007, the reefs have had the opportunity to recover. But corals grow slowly, and it therefore takes an extra-long time for them to grow large and spread. But things are progressing, and coral colonies are starting to re-form, and new corals have established themselves on the reefs.
Thanda Island puts a lot of resources into the active restoration of the reefs around Shungimbili. And to help nature along, Thanda has, among other things, started a project to grow coral fragments in underwater nurseries, which are then placed on the reefs when they have grown enough. Coral fragments that have been broken off and are lying on the seabed are collected and placed in the coral nursery where they remain until they are large enough to be planted back out onto the reefs.
Over the years, several different forms of artificial reefs have been experimented with. The first to be deployed around Shungimbili were bottle reefs.
In the nurseries, the small corals have optimal growing conditions. Here they are kept elevated from the seabed so that they do not risk being buried in the sand. They get a good water flow which ensures that nutrients and food reach the corals. At the same time, waste can be carried away by the currents. It takes between six months and a year for the coral fragments to grow to a size where they are ready to be planted on the reefs.
The first coral nursery at Shungimbili started in July 2018, testing two types of nursery structures: tables and trees. The test turned out well and paved the way for an expansion of the project. In late summer 2021, two new nurseries were established on rope structures in collaboration with the The Ropes of Hope, an NGO based on Mafia Island. Today, there are two rope nurseries, six tree nurseries, and three table nurseries. Together, they harbour over 9,000 coral fragments.
When the corals have grown large enough in the nurseries, it is time for them to be moved out onto the reefs. Corals have no roots but attach themselves to the substrate by secreting a calcareous skeleton. For the corals to be able to take hold, it is important that they are planted on a stable surface and secured properly. If there is the slightest movement in the substrate, the coral will not be able to attach itself and will have difficulties surviving. To secure the corals, several different methods are used depending on which substrate is available at the site. If there is enough stable ground, the corals can be planted directly on the reef.
When reefs are severely degraded, as in the case of Shungimbili, where dynamite fishing and drag netting had pulverized them, the stable substrates needed to plant corals are unavailable. Artificial reefs are then used to create a stable base. Over the years, several different forms of artificial reefs have been experimented with. The first to be deployed around Shungimbili were bottle reefs. They consist of a concrete foundation with embedded glass bottles that are perfect for placing corals in between. Several of these bottle reefs were created and laid out in the way that reefs spread naturally. Another solution are the hollow concrete pyramids. As well as providing a firm base, they have proven to be very popular hiding places for reef fish and all kinds of marine invertebrates.
But the construction most used to create artificial reefs are “reef stars”. They are very easy to handle, cover larger areas and are therefore more efficient. Reef stars are used successfully all over the world and consist of iron frames that are covered with a painted layer of cement and sand. This prevents rust and helps the corals to attach. The corals from the nurseries are attached to the frames with zip ties and even if you want to use as little plastic as possible this is the most successful method so far. A better alternative has not been found.
Creativity plays a large part in the construction of artificial coral reefs. Creativity and recycling were the keywords when the largest artificial reef structure to date was created from an old telephone tower. The tower was cut into sections, treated with the same concrete slab as the reef stars and placed at a depth of about 10 meters on the Villa Reef just south of the island. The corals that were planted on the structure have already grown a lot and many different fish live a better and more protected existence in and around the old telephone tower.
A vision for long-term nature conservation
As Thanda Island is situated in the heart of the Shungimbili Island Marine Reserve, the care of marine life means a lot to Thanda as a business, but also as an experience. After all, swimming over a living coral reef is a completely different experience than swimming over a flat rubble bottom. The rangers provided by Mafia Island Marine Park are crucial for the conservation of marine life and for supporting Thanda's current and future initiatives.
The continued focus of Thanda Island's conservation efforts is the marine biologists' monitoring of the reefs. The reefs are regularly inventoried and checked to assess their condition and development. This provides a better understanding of the ecosystem around the island and efforts can be made to strengthen the reef's resistance to natural shifts and the effects of climate change.
Thanda also strives to expand its efforts outside the marine nature reserve and therefore supports a wider network of conservation organizations in the area. Through collaborations with non-profit organizations such as Sea Sense and the Marine Megafauna Foundation, Thanda also contributes to the conservation of sea turtles in Tanzania and the research on whale sharks at Mafia Island.
Thanda’s mermaid, a symbol of the beauty of marine conservation
In addition to knowledge about ecosystems, animals and plants, creativity is also required when it comes to finding solutions for how we can restore the nature that we humans have damaged. Functional creativity is often tested. Aesthetic creativity, however, is not as common when it comes to coral reef restoration. But there are examples, and British sculptor and artist Jason deCaires Taylor has made a name for himself with his spectacular underwater installations. Works of art that are in constant change with the help of ocean organisms. And that will be completely integrated into nature.
Inspired by this award-winning artist, Thanda Island’s General Manager Antigone Meda wanted to create an underwater sculpture that would become part of the regular reef restoration work at Shungimbili. In 2019, Antigone began sculpting a mermaid in clay, a project that would take two years to complete. The sculpture was designed to promote natural growth of coral fragments. When the clay sculpture was ready, a fiberglass mold was built, which was then filled with concrete. To enable the transport of the mermaid to her new home on the reef, she was split in two.
It was a team-building task to get the sculpture in place, but since 2021, Thanda Island’s own mermaid watches over the nurseries and corals have found a home on her. Slowly but surely, she is transforming along with all the living things on the reef. And when she is completely integrated into the reef, she will lie there as a buried but strong symbol of the beauty of restoring nature to the way it was before we destroyed it. She also becomes a symbol of the long-term and solid work Thanda does for nature and the environment, a prerequisite for the experiences they want to offer their guests.
Subsidiary group
Thanda
Thanda Group operates in the hospitality industry, property development, and conservation. The crown jewel is Thanda Safari in...