The sizzling summer temperatures may be scaring away even the butanding (whale sharks) of Donsol Bay.
While record numbers of tourists are hitting the beaches of Sorsogon this summer, there are fewer and fewer sightings of Donsol's main draw-the gentle whale sharks, according to the World Wide Fund for Nature-Philippines. (WWF).
Donsol's surface water temperature these days averages 28.3 degrees Celsius, 2 degrees warmer than the average 26.1 degrees Celsius recorded in the summer of 2010, the WWF said.
"Our initial findings seem to indicate that the whale sharks are staying in deep water, possibly to avoid the heat," WWF whale shark expert Dave David said.
"They are also highly migratory creatures, so it is not easy to regularly predict their whereabouts," he added.
The last time this phenomenon of fewer butanding sightings occurred was in the summer of 2001.
The human factor
Apart from the warm sea surface temperatures, the WWF said the human factor could also have something to do with the elusiveness of the butanding this summer.
"Donsol now has far more visitors than it can handle. Coupled with the fact that sightings are decreasing, more and more interaction violations are being reported," WWF Donsol project manager Raul Burce said.
Some swimmers touch the sharks against the rules, and bancas tend to race one another whenever a shark is spotted, observed tourist Anton Lim.
Under the rules, only a single boat of six swimmers is allowed per shark. Boats are allowed to tour for three hours at a time.
Swimmers should be 3 meters away from the whale shark's body, and 4 meters away from its tail. They are allowed to interact with the butanding for 10 minutes, and they can neither touch nor use flash photography.
The WWF has called on tourists, boatmen and guides to stick by the guidelines. "By respecting the rules, we're minimizing our impacts on the ecosystem, especially the sharks," said Burce.
"The policies were designed not just to protect the whale sharks, but tourists as well. A 30-foot shark can accidentally swat a swimmer straying too close to its tail," he said.
The WWF is attempting to track whale shark movements through state-of-the-art tracking monitors, instead of relying solely on the trained eyes of spotters.
"Using just your eyes can be difficult, particularly if it is raining or overcast," said Allan Amanse, former president of the Butanding Interaction Officers Association.
"When it rains, the chance of a successful interaction drops," he said.
The new trackers utilize stationary sonar modules, which bounce sound waves off all solid objects. Large creatures such as whale sharks or shoals of fish can easily be made out. The trackers also monitor water temperatures, the WWF said.
The giant butanding (Rhincodon typus), a member of the shark family though not carnivorous, make their annual visit to feed in the waters of Donsol during the first half of the year.
The main attraction are the plentiful plankton-the microscopic animal and plant organisms that float in open waters and are the main food source for fish and whales- in Donsol during that time of year.
Though the whale sharks stop off in Donsol for only six months, their annual visit has given rise to a veritable tourist economy for the town residents of Donsol who are involved in organizing whale-watching activities.
Since the late 1990s, a multisectoral ecological program involving the private sector groups, including the WWF and government, has ensured that the whale sharks will continue to come. This involves, among other projects, the reforestation of the region's mangrove forests which are needed for the plankton to flourish.
Habitat for fireflies
One of the side benefits of sustaining the mangroves is the promotion of the habitat for fireflies which light up Donsol and its watery environs on dark nights.
With fewer sightings of the whale sharks these days, Donsol operators are now able to offer alternative firefly and mangrove tours for visiting tourists.