Between 2005 and 2007, researchers detected unusual aggregations of whale sharks in the waters of Madagascar, home to one of the world’s most unique biodiversity. From then on, many local divers and tourists reported spotting whale sharks around Nosy Be, an island off Madagascar’s northwest coast. Since then, whale shark tourism on the island has boomed and tourists from all over the world started visiting Nosy Be specifically to see and swim with these creatures. A study published in 2021 estimates that whale shark tourism in Madagascar’s Nosy Be generates $1.5 million USD for the local economy in a three-month season.
Stella Diamant, a conservation biologist, saw her first whale shark in 2014 after spending some time in Madagascar. She became so fascinated with the animals that she decided to take action and get involved in protecting them.
Two years later, The Madagascar Whale Shark Project (MWSP) was born, a foundation to improve data collection, protection measures and local regulations on megafauna in the area, and also an organization that is involved in raising awareness and empowering local communities. MWSP is now a registered private foundation that is studying and protecting whale sharks in the area and working on educating local communities and women.
When MWSP was first established, there weren’t any studies conducted on the island, which means that there wasn’t any data at hand yet. Stella and her team started from scratch and garnered scientific data by attaching satellite tags on sharks to receive signals whenever they come to the surface to eat. This technique helped them to better assess where the whale sharks would frequently go, and which locations were thus interesting to study. They also used acoustic tags to detect the location of animals when they are near a listening station.
With modest resources available in the country, they had to rely on multidisciplinary collaborations to move forward with their research. Whale sharks are known to be friendly animals that don’t harm humans as they only eat plankton and some fish, which encouraged people to swim and take videos of them. Little did they know that this footage would help with the progress of Stella’s research to gather as much information as possible about the sex, age, size, and movement of whale sharks on the island. With the help of scientists, MWSP staff, volunteers, and random divers, it was possible to collect data on the whale shark population, and behaviour in addition to other ecological data. The data was monitored, processed, analysed, and then published in peer-reviewed journals.
More than 400 whale sharks were identified on the island, and they named every one of them. Each whale shark can be recognized by a unique dots-and-waves-trademark right next to their side fin, or by scars that make them stand out from the rest. Although these giant creatures are highly migratory, they sometimes come back to the same place repeatedly. Proof of that, some whale sharks were spotted and recognized again in Nosy Be years after they disappeared from the coast.
Gross of the whale sharks identified by Stella and her team were located rather close to the coast, which is typical for juveniles to feed. These are usually between 3 and 8 meters long, unlike adults, whose size varies between 10 and 20 meters and stay usually in the deep ocean to feed. They can also dive deep in water (with the highest ever-recorded dive depth of 1928 meters) where they feed themselves with other tiny sea creatures.
In 2016, whale sharks were classified as endangered species and the number is rapidly decreasing with their population being halved in the last 75 years. The more research was done, the more Stella and her team detected the risks these animals are facing on a daily basis. While it is estimated that whale sharks can give birth to 300 or even 400 babies in one pregnancy, unfortunately only a few of them survive long enough to mature and reproduce further. Once they do reach maturity after 30 years, their average lifespan is between 80 and 130 or even 150 years. In other words, they are dying faster than they can reproduce.
Besides these natural deaths, there are numerous human-caused factors that are putting the sharks at risk of extinction. For instance, the collision of whale sharks with cargo ships, fishing and touristic boats is a common incident that cuts their bodies and causes severe injuries which can lead to death. In addition, the aggregation of boats would prevent them from coming to the surface to eat as they are very sensitive to noise which can lead to underfeeding. For this reason, MWSP developed a code of conduct and organised training sessions to inform tourists on ways to behave in water or on boats around whale sharks without harming and annoying them.
Another problem is pollution. Particularly, plastic bags and microplastics that float on the surface of water get stuck in the small esophagi of whale sharks. To minimize the overall damage of pollution to marine life, MWSP has organised several ocean cleaning initiatives.
On another note, whale sharks often get stuck in fishing nets. For example, it is known that whale sharks and tunas are considered water companions as tunas hide under their massive bodies to protect themselves from other sharks. So, when fishers are on the hunt for tuna with huge fishing nets, often whale sharks get caught as bycatch. In this case, they can die from being out of the water, or their fins get cut off before they are thrown back into the water. Often, the bodies are never found because they sink to the bottom of the ocean, so it is hard to do further research on death causes.
The team of MWSP has been actively supporting the development of legal protection as well as any local initiative to put end to illegal fishing, cutting the fins of sharks for lucrative benefits and other threats. Plus, they collaborated with the ministry of tourism and participated in local conservation initiatives to raise awareness of these issues. They now run education programmes with local schools to empower the next generation and educate them on environmental topics.
However, a lot of work still needs to be done on the island. Stella and her staff constantly recruit volunteers to help them collect data and improve their work. They also appreciate any donation to support their project and assist them to have a lasting impact on Madagascar.
Whale sharks are one specie among many others endangered today due to human activity or a loss of their habitats. High hopes are pinned on conservation projects and initiatives like The Madagascar Whale Shark Project, especially in places where official protection measures are absent. Conserving biodiversity is one of the main objectives in our fight against climate change to ensure sustainable management of our ecosystems.