Why Whale Sharks Move Around South Ari Atoll

Why do whale sharks appear in one part of South Ari one month and seem to vanish the next? A 2026 study suggests a big part of the answer is food. The paper, published in Scientific Reports in February 2026, analysed whale shark sightings from boat surveys between 2016 and 2019. The researchers compared them with sea-surface temperature and chlorophyll data.

Chlorophyll is often used as a broad sign of microscopic plant life in the water. That tiny life sits near the bottom of the food web, the one a whale shark ends up filtering.

The short answer: food conditions may help shape local movements

The researchers asked whether the amount of nutrients in the water helps explain seasonal changes in sightings in South Ari. The idea is simple. A huge filter-feeding shark needs places where food gathers, and ocean conditions change where that is.

But “linked to” does not mean “controlled by one switch.” A sighting record shows where animals are and also where people are looking. Temperature and chlorophyll tell part of the story, not every turn of a shark’s route.

The study uses several years of field observations and ocean data. It does not take one memorable season and turn it into a rule.

Is there a guaranteed whale shark season in South Ari?

No. Even where sightings are recorded over many years, the animals move. Conditions change from year to year. A boat may search one part of the atoll while a shark is somewhere else.

The study helps explain why local sightings change. It does not predict that a visitor will see a whale shark on a given date.

If a tour page promises certainty, ask what that promise means. A refund? Another trip? Or just hopeful words? Wildlife cannot sign a guarantee.

What the research means for responsible tourism

Long-term records help managers see when and where encounters happen. That supports better decisions about how people share the water with the animals. It also shows patterns that short visitor reports would miss.

For visitors, the same science invites a gentler mindset. Arrive curious. Follow local instructions. Let the shark choose its direction. Never cut across its path for a photo. Do not touch or crowd it.

A whale shark filtering food at the surface is already doing something extraordinary. It does not need a swimmer inches from its head. Wildlife encounters are unpredictable. Swimming with whale sharks should always follow local regulations and experienced professional guidance.

A better question to ask before booking

Instead of only asking, “Will we see one?”, ask, “How does your crew behave if a whale shark appears?” A responsible answer includes clear distance and approach rules. It includes being willing to end an encounter when the animal moves away. And it makes no promise that an animal will be there. Rules can change, so check the current ones locally.

The research gives us a better story than a calendar. These sharks respond to a living, shifting ocean. Use the science to ask an operator better questions, not to expect a guaranteed encounter.

Questions people ask

Wildlife encounters are never guaranteed and never forced. Ocean Calling works only with vetted, ethical local operators, and every animal is free to approach, or not, entirely on its own terms.