In a remote Indonesian bay, the world's largest fish have learned to beg for food from local fishermen, creating a unique scientific puzzle.
A unique underwater cafe
In Indonesia's Cenderawasih Bay, a strange and wonderful interaction occurs daily. In this bay, the planet's largest fish, the whale shark (Rhincodon typus), gathers around traditional lift-net fishing platforms known as 'bagans'. Fishermen on these wooden structures use powerful lights at night to attract schools of small baitfish, which they then haul up in large nets. The whale sharks, drawn by the scent and commotion, have learned a remarkable behavior. They approach the bagans and suck directly at the nets, slurping up escaping baitfish, or simply wait for fishermen to hand-feed them.
This learned feeding only happens in Cenderawasih Bay. The local fishermen, who have been using bagans since the 1950s, believe the sharks bring good luck and willingly share their catch. This creates a reliable, year-round food source for the sharks, turning the bay into an unparalleled natural laboratory for studying a species that is otherwise highly migratory and elusive. The interaction allows scientists a rare, close-up look at these gentle giants, which can grow up to 18 meters long.
A scientific anomaly
The Cenderawasih Bay aggregation presents a scientific puzzle. Unlike other known whale shark hotspots, which are typically seasonal and attract a mix of individuals, the population here is overwhelmingly composed of juvenile and sub-adult males. A comprehensive 13-year study identified 268 individuals, revealing a male-to-female ratio of nearly 9 to 1. Most of these sharks measure between 3 and 8 meters in length, suggesting the bay acts as an important nursery or feeding ground where young males can grow.
Many of these sharks stay in the area. Satellite tagging studies have confirmed that while some individuals undertake long migrations, a significant portion of the population exhibits long-term residency in the bay. Re-sighting data shows some sharks have been present in the area for over a decade. This unusual, non-migratory behavior is likely linked to the constant food supply from the bagans. The International Union for Conservation of Nature (IUCN) lists the whale shark as an Endangered species, with global populations declining by over 50% in the last 75 years. This makes the predictable and accessible Cenderawasih population exceptionally important for global conservation and research efforts.
💡Fun Facts
The spot patterns on a whale shark are unique to each individual, similar to a human fingerprint, and are used by researchers for photo-identification.
Despite their immense size, whale sharks are filter feeders whose diet consists of plankton, krill, and small fish like anchovies and sardines.
Whale sharks are the largest fish in the ocean, with the largest confirmed individual measuring 18.8 meters.
The skin of a whale shark can be up to 15 centimeters thick, providing excellent protection.
Access is year-round as the whale sharks are resident, but trips are dependent on liveaboard or tour operator schedules. The best interactions are in the morning.
Admission
Access requires joining a chartered tour or liveaboard boat and paying national park entrance fees.
Accessibility
The bay is extremely remote. Access is by multi-day liveaboard boats, typically departing from Nabire or Manokwari. Travel involves flying to these regional airports first.