Oslob Whale Shark Tourism: What the Research Shows

It is early morning in Oslob, on the island of Cebu in the Philippines. Small boats paddle out, fishermen drop food into the water, and within minutes a whale shark is gulping at the surface a few metres from a line of swimmers. Is whale shark tourism at Oslob a problem? The research gives a clear main answer: the sharks are fed every day, and over the years that feeding has changed how long many of them stay and how they behave around boats and people.

That is exactly why Oslob is one of the most studied places in wildlife tourism. Scientists have been watching it closely since 2012. We think their findings are worth reading before you book anything. Not to tell you what to think, just so you start from the same information they have.

How Oslob actually works

Encounters in Oslob are built around daily provisioning, which simply means feeding. Local fishermen hand-feed the whale sharks from small boats each morning to keep them close to shore. This is what makes sightings so reliable, compared with places where you wait for a natural migration or a seasonal plankton bloom. Visitors then watch from the boats or in the water, close to where the feeding happens.

Because the food arrives at the same spot, at roughly the same time, every day, many of the same sharks keep coming back. For travellers, this means near-certain sightings. For the sharks, it means a daily routine that would not exist without people.

What has the research on Oslob whale sharks found?

The first detailed study of this population was published in PeerJ in 2014 by Araujo and colleagues. They photo-identified 158 individual whale sharks at Oslob between March 2012 and December 2013. Most were young males: 129 males (82%), 19 females and 10 of unknown sex. About a third of them (54 sharks, 34%) were seen being hand-fed by fishermen.

The difference in how long the sharks stayed is striking. The fed sharks had a modelled average stay of about 45 days, against about 22 days for sharks that were not fed. One shark was present on 572 of the 621 survey days, so it basically never left. The same study also saw propeller scars on 47% of the sharks, a reminder of how many boats share this small piece of sea.

A longer analysis, published in Royal Society Open Science in 2017 by Thomson and colleagues, covered three years and identified 208 individuals. The patterns were very different from shark to shark. Some visited only once, others came back now and then, some were seasonal and some stayed all year round. Year-round residency is not what you would expect from a species that usually travels with its food.

A 2015 follow-up in PeerJ, by Schleimer and colleagues, looked at behaviour and at how well the site's own code of conduct was followed. Sharks with a longer history at Oslob were less likely to avoid touches or contact with boats. Newly identified sharks slowly started arriving earlier at the feeding site after their first sighting, which the authors read as learning to link the place with food. And breaches of the minimum 2 m distance rule rose from 79% of observations in 2012 to 97% in 2014. The authors recommended better enforcement and less feeding, as a precaution.

A later study by Legaspi and colleagues, using in-water data from 2015 to 2017, found a similar picture: people were closer than 2 m to the sharks in 93% of surveys.

The trade-off behind the predictability

None of this means a shark is being hurt in any single moment. What the data points to is a slower change that builds up over time: in how long the animals stay, how close people get, and how the sharks react to boats and swimmers.

There is a real difference between an encounter shaped by an animal's own migration and food, and one shaped by daily feeding. The first is unpredictable by nature. You go when the season is right and you hope. The second is far more reliable, which is exactly why feeding-based models like Oslob's became popular, and exactly why researchers have spent more than ten years documenting how that reliability is made. We have written more about this difference in how to recognise an ethical encounter.

Other places to see whale sharks in the Philippines and beyond

Whale shark encounters also exist without feeding. Donsol, in Sorsogon province, is the best-known Philippine example. There the sharks come on their own to feed on plankton. WWF credits strict enforcement of the interaction guidelines, including the ban on feeding, as a key reason the site works, and says it has recorded 771 whale shark sightings there since 2007. Snorkelling only is the rule, with no scuba gear in the water with the sharks. Sources disagree on the exact season and on group limits, so check with the local interaction office before you go.

Sightings at places like this are never guaranteed the way they are in Oslob. That trade-off, less certainty in exchange for less influence on the animal, is the heart of the whole comparison. For a wider look, see our guides to ethical whale shark encounters around the world and ethical whale shark encounters in the Philippines.

The ethical layer: where we stand

We do not go to Oslob, and this is not about judging anyone else's choices. Our own rule with any marine animal is simple: we never chase, touch, bait or feed, and we never try to make an animal change what it would naturally do. We only work with local guides who keep the same standard. The short version of that thinking is in how we decide what counts as an ethical wildlife experience. Sightings on our trips are never promised. That is the honest cost of not feeding anything.

If you already have a trip to Oslob booked, you can still make choices that help: stay well beyond the 2 m minimum, never touch a shark, and keep your visit short and calm. On any boat day, a roll-top dry bag for your phone and passport is worth having, and a rash guard keeps you covered in the water without a thick layer of cream. The Philippines page of our Ocean Atlas gives the wider picture. And if this made you curious about meeting the ocean this way, have a look at our Moalboal referral trip, also on Cebu. Through Ocean Match we connect you with a vetted local team, and the focus there is the reef and its sardines, not whale sharks.

Whale sharks are listed as Endangered on the IUCN Red List. Wildlife encounters are unpredictable. Swimming with whale sharks should always follow local regulations and experienced professional guidance.

Questions people ask

Does feeding harm the whale sharks in Oslob?

Research has not shown that a single feeding encounter injures a shark. Published studies do show changes in behaviour among regularly fed sharks: longer stays (about 45 days on average for fed sharks against about 22 for unfed ones in the 2014 study), year-round residency for some, less avoidance of touches and boats, and earlier arrival at the feeding site.

How many whale sharks have been identified at Oslob?

A 2014 study identified 158 individuals between 2012 and 2013, mostly males. A 2017 study covering three years identified 208.

Do tourists follow the 2 m rule at Oslob?

Mostly not, according to the research. Breaches of the 2 m minimum distance rose from 79% of observations in 2012 to 97% in 2014, and a later study found people within 2 m in 93% of surveys from 2015 to 2017.

Are the whale sharks trapped in Oslob?

No. They are not physically confined and can leave. Some visit once, some come seasonally and some stay all year. Crowding around the sharks is a separate issue from confinement.

Where can I see whale sharks without feeding in the Philippines?

Donsol in Sorsogon is the best-known site with natural, unfed encounters. Feeding is prohibited there and only snorkelling is allowed. Sightings are not guaranteed.

Does Ocean Calling go to Oslob?

No. We do not visit sites where animals are fed for tourism, and we never promise a sighting.

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.

Sources & further reading

1. Araujo, G. et al., 2014. Population structure and residency patterns of whale sharks, Rhincodon typus, at a provisioning site in Cebu, Philippines. PeerJ 2: e543.
2. Schleimer, A. et al., 2015. Learning from a provisioning site: code of conduct compliance and behaviour of whale sharks in Oslob, Cebu, Philippines. PeerJ.
3. Thomson et al., 2017. Feeding the world's largest fish: highly variable whale shark residency patterns at a provisioning site in the Philippines. Royal Society Open Science.
4. Legaspi, C. et al., 2020. In-water observations highlight the effects of provisioning on whale shark behaviour at the world's largest whale shark tourism destination. Royal Society Open Science 7: 200392.
5. Asia News Network, 2025. In Philippines' Donsol, whale shark conservation bears fruit.
6. Poston, L. (WWF Media Relations). Swimming with whale sharks in Donsol.
7. Australian Geographic, 2016. Vulnerable to endangered: whale sharks one step closer to extinction (reporting the IUCN reassessment).

Further reading on Ocean Calling: More from the journal · Wildlife & the law · See the retreats · Ocean Atlas