Whale sharks (Rhincodon typus), fascinating large creatures, live in the warm tropical ocean waters. Whale sharks are the largest fish species in the world with a length of up to 18 meters and a weight equivalent to a city bus. However, behind their stunning size, these sharks are famous for their calm and friendly nature, deviating from the common belief that They are ferocious predators.

This subtle giant has attracted the attention of many divers, coastal communities, and researchers. However, behind that admiration there is an alarming reality: human activities have caused whale shark populations to decline drastically in many places around the world, including in Indonesia.

Whale sharks are the only species of the family Rhincodontidae. Andrew Smith first recorded this species in 1828 off the coast of South Africa. Although referred to as "sharks" and "whales", these animals are scientifically classified as sharks because they have a cartilaginous skeleton rather than the bones of actual marine mammals. One of the most recognizable features of whale sharks is the white spotted pattern on its body which is grayish-blue. The unique patterns that each individual possesses, similar to human fingerprint patterns, can be used for identification in population studies and migration tracking.

Around the world, whale sharks live in tropical and subtropical waters, and Indonesia is one of its main habitats. One of the most mobile fish species in the world, they are known to migrate thousands of kilometers following ocean currents and food availability.

In some areas in Indonesia, Whale Sharks have names according to the beliefs of the local community. In the Balikupup Area, East Kalimantan it is called Hiu Mbok (Grandmother Shark) while in Muncar, East Java it is named Hiu Kekakek (Grandfather Shark) this is based on the belief that Whale Shark is part and incarnation of their ancestors. Other names are Kareo Dede (Labuan Bajo, NTT); Deaf Shark (Sumbawa, NTT); Gurano Bintang/Hiu Bintang (Cendrawasih Bay, West Papua); Munggianggo Hulalo/Moon Shark (Botubarani, Gorontalo).

Whale Shark Ecology

Whale sharks can be found living in a variety of places in warm waters, from shallow coastlines to open oceans. They are often found in places where there is a lot of plankton, such as around atolls, river deltas, or areas that are experiencing upwelling. They are usually present somewhere during the season, depending on the cycle of marine productivity.

Whale sharks feed on plankton and play an important role in maintaining the balance of marine ecosystems. Every day, they filter thousands of liters of seawater to retrieve zooplankton, fish eggs, and crustacean larvae, indirectly helping to control populations of marine microorganisms.

Whale Shark filter feeding plankton at night,
Thaa Atoll, Maldives (Photo Credit : Arturo de Frias Marques)

Interestingly, however, recent studies show that whale sharks don't just eat plankton; Some eat small fish and even benthic organisms, which live on the seafloor. This suggests that whale sharks can adapt to the way they eat. These results suggest that whales are not entirely dependent on plankton and can adapt to changes in the environment.

Morphology

The whale shark's highly efficient body design for eating particles is one of its wonders. Whale sharks are real marine giants that weigh about 20 tons and are up to 18 meters long. Its fusiform (torpedo-like) body shape, which reduces water resistance when swimming, allows it to move very gracefully and efficiently in the sea.

The size and growth of the whale shark (Photo Credit : Steveoc 86)

Having about 300 to 350 rows of small teeth, the mouth of a whale shark can be 1.5 meters wide. However, these teeth are not used to chew or bite food; Instead, they filter food through a process referred to as a "feeding filter ram," in which water enters through the mouth and passes through dental rakers, special filtering structures that hold food particles.

The adaptation of his brain is no less interesting. As shown by research conducted by Yopak and Frank (2009), whales have very large brains and have complex structures. In particular, the part of the brain responsible for spatial sensing and processing is the most prominent. This improves their ability to identify the surrounding environment and navigate remote migrations. Whale sharks are highly adapted to their environment, both as ocean explorers and food filters. This is due to its unique structure and sturdy outer morphology.

Social Behavior and Adaptation

Whale sharks don't always live in one place. In some places, such as Ningaloo Reef in Australia, Isla Holbox in Mexico, or Cenderawasih Bay in Papua, they are often seen gathering in large numbers. This happens especially during the abundant plankton feeding season. In marine ecotourism, this phenomenon has become very interesting and is referred to as "aggregation."

They usually swim calmly and slowly, but they are capable of diving to depths of more than 1000 meters in vertical diving. It is believed that these dives involve searching for food, avoiding predators, or navigating through ocean temperature gradients.

Whale sharks are highly adaptive when interacting with humans. In tourist spots where you can swim with whale sharks, such as in Oslob (Philippines) and Cenderawasih Bay, whale sharks often accept the presence of humans. However, this tolerance carries risks. Studies show that repeated interactions can alter their natural behaviors, such as diet and migration, and also increase the risk of getting injured from boats or propellers.

Interestingly, recent studies show that whale sharks can also "eat from the bottom of the sea", i.e. eat food from the seafloor. This suggests that this species not only relies on plankton on the surface but is also capable of exploring a variety of food sources, adding to the evidence that they are flexible in the environment.

Threats Whale Sharks Face

Despite their gigantic size and seemingly unshakable, whale sharks face serious threats—mostly from human activities. In many parts of the world, whale shark populations are declining, even in some areas they are barely visible.

• Bycatch and Hunt

  One of the main threats is bycatch by large-scale fishing vessels. Whale sharks caught in nets—albeit accidentally—are often severely injured or die from being unable to breathe without active swimming. In the past, whale sharks were also hunted for their meat, fins, and oil, especially in East Asian countries.

• Habitat Destruction

  Degradation of the marine environment due to pollution, mining activities, and coastal development has an impact on whale shark habitats and migration routes. Oil spills, microplastics, and chemical contamination have been identified in the bodies of some whale shark individuals, indicating that this species is not immune to pollution dangers.

• The Impact of Unmanaged Ecotourism

  Ecotourism can actually be a tool for conservation, but if it is not properly regulated, it can actually backfire. In some popular destinations, the practice of feeding whale sharks to attract tourists leads to natural behavioral changes and dependence on humans. In addition, physical damage due to collisions with tourist boats or propellers is also a concern.

Global and National Conservation Status

1. Global Status

   Globally, Rhincodon typus has been included in the IUCN Red List with "Endangered" status since 2016. This is based on data on a significant population decline of more than 50% in recent decades. Whale sharks are also protected in the CITES Convention (Convention on International Trade in Endangered Species of Wild Fauna and Flora) Appendix II, which restricts international trade in this species.

   Global conservation efforts include satellite tracking to monitor movements, fisheries regulation, and the establishment of marine protected areas (MPAs) that cover their migration routes.

2. Status in Indonesia

   Indonesia is one of the important habitats for whale sharks in Southeast Asia. Significant populations are found in Papua (Cenderawasih Bay), Maluku, and the eastern part of Sulawesi. Realizing the importance of this species, the Government of Indonesia designated whale sharks as a fully protected animal through the Decree of the Minister of Marine Affairs and Fisheries No. 18 of 2013. This regulation also includes the National Action Plan for Whale Shark Conservation (2021-2025) which is outlined in the Ministry of Fisheries and Fisheries Number 16/2021.

   As a fully protected animal, it means that all forms of capture, utilization, and trade of whale sharks in Indonesia are illegal. Violations of this rule can be subject to criminal sanctions based on Law No. 31 of 2004 concerning Fisheries. Regulations on whale sharks in Indonesia emphasize full protection and sustainable management, with the aim of preserving the existence of this species and marine ecosystems.

   However, the biggest challenge is not only in regulation, but in law enforcement and public education. There are still cases of whale shark catching, whether intentional or not, as well as tourism practices that have the potential to damage the natural behavior of this species. Therefore, whale shark conservation requires a holistic approach—combining science, policy, and community participation.

Conservation Efforts and Future Hope

Whale shark conservation is a complex challenge, but that doesn't mean it's impossible. The success of the conservation of this species relies heavily on deep scientific understanding, government policy support, and public awareness and participation.

• Technology-Based Research and Monitoring

  One of the key approaches that is now being developed is the tracking of whale shark movements using satellite technology and tagging. With this tool, scientists can more accurately study their migratory pathways, feeding behavior, and important habitats. In Indonesia, several collaborative initiatives have been undertaken by LIPI (now BRIN), KKP, and international partners to understand the movement of whale sharks in Cenderawasih Bay and other waters in eastern Indonesia.

  In addition, the use  of automated underwater cameras and artificial intelligence (AI)-based photo-identification analysis also allows for the identification of individuals quickly and efficiently. It is very important to know the population dynamics and trends of individual visits to a particular location from year to year.

• Community-Based Conservation

  The success of conservation cannot only rely on government policies or research institutions. In many locations in Indonesia, coastal communities are the first to interact with whale sharks. Therefore, community-based conservation  initiatives are key.

  For example, in Cenderawasih Bay, the local government together with NGOs and indigenous peoples have formed a whale shark tourism management group that not only keeps tourism interactions safe for animals, but also brings direct economic benefits to local residents.

  Educational programs are also important, especially for fishermen, tourism actors, and the younger generation. Campaigns on the importance of whale sharks in marine ecosystems, prohibitions on hunting, and proper ways to interact during tourism, have been shown to reduce the number of conflicts and increase public support for the protection of this species.

• Harmonization of Ecotourism and Conservation

  Ecotourism, if managed responsibly, can be a very effective conservation tool. The experience of seeing or swimming with whale sharks can create an emotional connection between tourists and animals, fostering concern for marine conservation.

  However, regulations must be strictly enforced. The number of vessels, the duration of interactions, and the safe distance between humans and whale sharks should be clearly regulated. In some places, certification systems for whale shark tour guides have been implemented, complete with ethics and safety training.

  This harmonization between economic benefits and ecological sustainability is the foundation of a healthy future of ecotourism and long-term conservation.

Conclusion

Whale sharks, as the largest fish in the world, are an important symbol of the biodiversity of tropical seas. Not only is it physically stunning, but it also plays an important ecological role in maintaining the balance of marine ecosystems. Unfortunately, its existence is increasingly threatened by human activities—from bycatch, poaching, habitat destruction, to uncontrolled ecotourism.

In the midst of the complexity of these challenges, Indonesia has a great responsibility as one of the main areas for the distribution of whale sharks. The legal protection status that has been granted by the Indonesian government is a big step, but it still needs to be supported by consistent implementation in the field, continuous scientific research, and active involvement of local communities.

Through collaboration between scientists, policymakers, tourism actors, and local communities, we have the opportunity to ensure that future generations can still witness the presence of this gentle giant in Indonesia's seas.

PROTECTING WHALE SHARKS MEANS SAFEGUARDING THE FUTURE OF OUR OCEANS.

-Yuni Sulaiman

References

Guzmán, H., Collatos, C., & Gómez, C. (2022). Movement, behavior, and habitat use of whale sharks (rhincodon typus) in the tropical eastern pacific ocean. Frontiers in Marine Science, 9. https://doi.org/10.3389/fmars.2022.793248

Rowat, D. and Brooks, K. (2012). A review of the biology, fisheries and conservation of the whale shark rhincodon typus. Journal of Fish Biology, 80(5), 1019-1056. https://doi.org/10.1111/j.1095-8649.2012.03252.x

Stacey, N., Karam, J., Meekan, M., Pickering, S., & Ninef, J. (2012). Prospects for whale shark conservation in eastern indonesia through bajo traditional ecological knowledge and community-based monitoring. Conservation and Society, 10(1), 63. https://doi.org/10.4103/0972-4923.92197