Is Oslob Whale Shark Watching actually ok?
At Oslob, whale sharks are fed every morning so visitors can swim beside them. But Oslob is not a simple story. The tours have given a fishing community a far better standard of living, and some respected scientists argue there is little evidence that the feeding harms the sharks. We give their case real space here, next to the research that concerns us.
Whale sharks have been protected in the Philippines since 1998, and the IUCN lists the species as Endangered. Day tours to Oslob are sold throughout Dumaguete, and at several dive resorts in nearby Dauin. Occasionally our volunteers ask if they should go. We see whale sharks on our own dives too, unfed and on their own terms, and in the year to April 2026 our divers logged six at four of the sites we monitor, up from almost none a decade ago. The answer is not black and white, and we reached our conclusion only after careful deliberation. You may find it helpful if you are considering going.
How Oslob began
Whale sharks were no strangers to Tan-awan, the fishing village in Oslob where the tours take place. Fishermen there had known them for generations, and some accounts say they fed them small shrimp long before any tourists came, but until 2011 the sharks were seen only now and then and there was no whale shark tourism to speak of. Organised tours began in early 2012, and within months hundreds of visitors were arriving every day.
Tan-awan’s fishermen run the tours through their sea wardens and fishermen’s association. Under the town’s ordinance, 60% of the income goes to the fishers’ associations, 30% to the municipality and 10% to the village. State auditors recorded ₱182.7 million in whale shark watching income in 2019. No full-year figure has been published since the pandemic, but Oslob has since been reclassified from a fourth-class to a first-class municipality, a rise largely credited to whale shark tourism.
Each morning, boatmen paddle out in small outrigger boats and hand-feed the sharks sergestid shrimp, known locally as uyap. In 2019, the feeders used 150 to 400 kg of shrimp a day. Visitors snorkel or watch from the boats for about 30 minutes, in a marked area just offshore.
Visits peaked at 508,000 in 2018, averaging about 1,400 a day. That year, the town and the fishers’ association agreed to limit visitors to 800 a day. In May 2026, local reports put daily visitor numbers at 800 to 900. Presently fees run 500 php for locals and 1000 for foreigners wanting to snorkel. Scuba diving is 1500 php.
Current status on whale shark research
Researchers from the Philippine group LAMAVE recorded Oslob’s sharks almost daily between 2012 and 2020. LAMAVE then put its Oslob work on hold, saying local and regional stakeholders were unwilling to move away from unsustainable practices. During the time in Oslob, a lot of significant research was published.
The 2014 LAMAVE study identified 158 whale sharks at Oslob in under two years and found that they stayed far longer than at other aggregation sites, with a clear difference between the sharks seen being fed and the rest. A three-year follow-up of 208 sharks later found every pattern, from a single visit to year-round residency.
Most sharks pass through. The concern is the minority that remain, because time spent at the feeding site replaces time spent foraging naturally.
Sharks with a long history at Oslob also learned the routine, arriving on average five minutes after the feeder boats and feeding vertically at the surface more often, according to a 2015 study of the site. Sharks tagged for a 2020 study spent about six times as much time at the surface during feeding hours as on days when they stayed away.
Regular visitors also reacted less to touching and contact with boats, while fed sharks were less likely to move away from people.
In fairness Oslob has a code of conduct, but keeping an excited crowd back from a large animal swimming towards food is difficult. Breaches of the 2 m minimum distance rose from 79% of surveys in 2012 to 97% in 2014, and between 2015 and 2017, 93% of surveys still found people closer than 2 m. Despite telling people not to, many cannot help but touch the sharks either wilfully or by accident. In 2018, there were an average of 40 boats in the interaction area.
Nearly half of the sharks identified in the first two years carried propeller scars. A later study of scarring found that sharks visiting regularly had significantly more scars than occasional visitors, mostly nicks and abrasions from boats and ropes, and many propeller injuries appeared despite a ban on propellers in the feeding area.
The authors of the 2015 study warned that as sharks become less wary of boats and people, they face a greater risk of injury and harmful encounters with fishing gear.
In September 2019, researchers fitted 16 sharks with accelerometers, a kind of fitness tracker, and found that the sharks’ activity doubled during tourism hours as they move around boats and each other. Using a model of the sharks’ energy use, the team estimated that their metabolic rate rose by 57 to 72%. The same model suggests that the food provided probably covers the extra energy used. The authors recommended changing the way feeding is run rather than the amount of food given.
The feeding also affects the reef beneath it. A study of the reef off Tan-awan, carried out when up to 50 tonnes of shrimp a year were being fed over it, found under half the coral density of a reference site further along the coast, 20% more macroalgae, a less diverse coral community dominated by hardy, fast-growing species, and signs of nitrogen pollution from human sources, and the 2019 feeding figures above suggest the amount of shrimp has grown since.
In defence of Oslob
Oslob’s defenders begin with people, and they have a point. Researcher Judi Lowe describes Tan-awan before the tours as one of the poorest fishing communities in the Philippines. A study found that the operation provided livelihoods for 177 fishers and generated about US$18.4 million in ticket sales during its first five years.
That income also pays for protection. According to the same study, the fishers fund sea wardens and police patrols that guard the sharks against poaching, and help manage five marine reserves. Whale sharks are protected by law, but poaching still happens in parts of the country, so supporters of Oslob argue that a shark staying near a guarded shore is safer than one that wanders.
Some scientists also challenge the research itself. In 2019, Mark Meekan of the Australian Institute of Marine Science and Judi Lowe reviewed the studies published by that point and called them fundamentally flawed, citing the lack of a baseline from before feeding began, limited methods and over-interpreted results. They note that whale sharks also stay for long periods at Donsol, where they are not fed.
They also note that most of the critical studies came from LAMAVE and its partners, and while shared authorship doesn’t make findings wrong, it does mean few of them have been independently repeated. Later work has added new methods rather than independent checks, with the energy study, led by Flinders University, using tags instead of in-water observation, and the reef study, co-authored by LAMAVE researchers, measuring the reef itself.
Where the evidence actually stands
Some findings are well supported, while others remain contested. Feeding clearly changes the behaviour of individual sharks at Oslob. No study has established whether it harms the wider population.
| Question | What the research shows | What we're uncertain about |
|---|---|---|
| Does feeding change behaviour? | Yes. Regular visitors arrive with the boats, feed vertically, stay near the surface and avoid people less. | Whether the changes carry over once a shark leaves Oslob |
| Do the sharks stay longer? | Some do. A minority become seasonal or year-round residents. | Whether this differs from natural sites. Critics point to long stays at Donsol, where sharks are not fed. |
| Are they injured? | Regular visitors carry more scars, including propeller cuts. | How many of the scars come from Oslob itself, and if Oslob behaviour is learned and then repeated elsewhere |
| Is the population harmed? | No study has shown this. | Long-term effects on survival, breeding or migration |
| Does the reef suffer? | Locally yes. Reefs show more macroalgae and signs of nitrogen pollution compared with a nearby reference site | How much is caused by feeding rather than other coastal pressures |
How we weigh it
Whether the population declines is not the only test. Individual sharks matter. A shark injured by a propeller, crowded by dozens of boats or touched by swimmers is harmed, whatever happens to the species as a whole. Precaution fits this species. Whale sharks are endangered and long-lived, with long generation times, so harm becomes apparent late and takes decades to reverse. The best-practice guide for shark and ray tourism, written by WWF, Project AWARE and the Manta Trust, calls for a precautionary approach wherever animals are fed, supported by a written plan and monitoring. Lastly, for visitors, caution costs little. Wild encounters are available in Sogod Bay and Donsol, without feeding.
The cost of change for Tan-awan is significant, and we cannot pretend otherwise. That is why our advice focuses on visitors’ choices, and why we are in favour of a gradual, funded change in Oslob rather than closure. Our own diving follows the Green Fins code of conduct, which asks divers and operators not to feed marine life at all. Compliance with best practices can be a powerful driver of tourism too, even if the marketing is different.
We don’t believe the answer is to shut Oslob down overnight. Bohol’s closure left people without work, and our own work alongside local governments in Negros Oriental has taught us that conservation rules only last when the people they affect can still make a honest living. Researchers and officials have already proposed some sensible steps to reduce pressure on the sharks without ending the income, but ultimately implementing these measures are decisions that belong to the people of Oslob.
- Change how the feeding is run. The energy study recommended changes to operations, so the whale sharks spend less effort.
- Enforce the distance rules. National rules ask swimmers to stay 3 m from a whale shark’s body and 4 m from its tail.
- Enforce the visitor cap. The 800-a-day limit agreed in 2018 only helps if it is kept.
- Protect sharks from propellers. Researchers have long recommended propeller guards. Regulating boat speeds is a sensible move too.
Another concern: The success of Oslob is a template
In 2012, within months of the first whale shark tourism in Oslob, Moalboal on Cebu’s west coast proposed its own feeding ordinance. The proposal was dropped only because the whale sharks failed to appear.
In 2019, a private operator began feeding whale sharks in Lila, Bohol, and sites in Alburquerque and Dauis followed. The Lila operator had no business permit, and none of the sites had clearance from the environment department. Here inspectors later found krill in the water and a foul smell over the interaction areas. When the province closed the sites in February 2025, about 135 people in Lila lost their jobs. The governor stressed that watching whale sharks was fine and that feeding was the problem. Bohol has since passed an ordinance banning feeding and allowing only natural, unprompted encounters, and plans to reopen under those rules.
Pintuyan in Southern Leyte built its whale shark tourism without feeding. After a benchmarking visit to Oslob, its tourism officer admitted the town had been tempted by the feeding model, pointing to one year when Oslob’s tours earned US$1.5 million against Pintuyan’s US$50,000, though so far Pintuyan has kept to its no-feeding rules.
Copies may also lack Oslob’s sea wardens and patrols. In 2026, Mylene Sadagnot, a marine biologist at Cebu Normal University, warned that sharks that are safe where they are fed may become easy targets for poachers elsewhere.
Where to see whale sharks instead
Wild whale sharks visit several parts of the Philippines in season, where local communities run encounters without feeding.
Sogod Bay, Southern Leyte: In Pintuyan, on Panaon Island, encounters are run by a community group of about 60 trained spotters and guides, all local fishermen. Feeding, touching and scuba are not allowed, and swimmers keep 3 m from the sharks. The season runs from 1 October to 1 June, and the 2026 season drew 9,842 visitors, up from 2,040 in 2023.
Donsol, Sorsogon: Donsol was the country’s first whale shark destination, developed with support from WWF-Philippines. Each boat goes out with a spotter and a trained Butanding Interaction Officer, and all encounters are snorkelling only. The season usually runs from about November or December to May, with the peak from March to May.
Bohol: Bohol plans to reopen whale shark watching without feeding. Check the current status before you go.
Our guide to diving in the Philippines covers Sogod Bay and Donsol in more detail.
How to choose a responsible operator
- No feeding, no promises. Wild sightings can’t be guaranteed. If one is promised, ask how.
- A briefing first. Good operators explain the rules on distance, touching and photography before anyone enters the water.
- Small groups and space. Look for limits on swimmers per shark, and boats that idle or cut their engines near the animals.
- No scuba, no flash. Encounters at the Philippines’ dedicated whale shark sites are snorkelling only, and flash photography is not allowed.
- Green Fins membership. Green Fins members are assessed against an environmental code of conduct.
Frequently asked questions
Is Oslob whale shark watching ethical?
In our view, not as it operates today. Feeding changes the sharks’ behaviour and exposes them to crowding, contact and injury for an encounter available at wild sites without feeding. The long-term effects remain unknown, and we think an endangered species warrants caution.
Is feeding whale sharks legal in the Philippines?
Four national departments issued joint rules for marine wildlife tourism. Section 8.3 prohibits provisioning, meaning luring, baiting or feeding animals, at dedicated interaction sites, and Annex I includes Oslob among those sites. How come the rules are not applied to Oslob is unclear: the town still operates under its own 2012 ordinance, apparently with provincial support.
Do the whale sharks live at Oslob all year?
Most sharks pass through, but a minority remain for weeks, months or all year. Sightings still vary: no sharks appeared for four days in May 2026, and the town said they were feeding on natural plankton nearby.
Hasn’t the feeding helped the town?
Yes. The tours have supported 177 fishers, the municipality and the village, and help pay for sea wardens and marine reserves. That is why we believe any change has to protect those livelihoods.
Where can I see whale sharks without feeding?
In Sogod Bay, Southern Leyte, from October to June, and in Donsol, Sorsogon, from about November to May. Our guide to diving in the Philippines has the details.
Suggested further reading
This post draws on published research, news reporting and Philippine regulations as well as our own experience. If you would like to dig into the question yourself, these are the places to start:
- Population structure and residency patterns of whale sharks at a provisioning site in Cebu, Philippines, Araujo et al., PeerJ (2014). The first large study of Oslob’s sharks, showing how much longer the fed sharks stay than sharks at natural sites.
- In-water observations highlight the effects of provisioning on whale shark behaviour, Legaspi et al., Royal Society Open Science (2020). Three years of observations on crowding, contact and how fed sharks respond to people in the water.
- Estimating the energetic cost of whale shark tourism, Barry et al., Biological Conservation (2023). Uses accelerometer tags to measure how hard the sharks work during tourism hours, and whether the food makes up for it.
- Does provisioning for tourism harm whale sharks at Oslob?, Meekan and Lowe, Tourism Management (2019). The main scientific critique of the research above, arguing that the evidence of harm is weak.
- Linking livelihoods to improved biodiversity conservation: Oslob Whale Sharks, Lowe, Tejada and Meekan, Marine Policy (2019). The case for Oslob as a livelihood and conservation success, from the fishers’ side.
- Joint Memorandum Circular No. 01, Series of 2020, DOT, DA, DILG and DENR. The national rules for marine wildlife tourism; section 8.3 and Annex I cover feeding and list Oslob.
