|A diver spots a whale shark. Photo provided by World Wildlife Fund
MANILA, Philippines -- If you want to spot a whale shark, more commonly known as butanding among Filipinos, Donsol in Sorsogon is still the best place to visit.
According to the World Wildlife Fund (WWF), Donsol hosts the most whale sharks in the Philippines with at least 377 identified by the group -- more than any other area in the country.
In a statement released on Wednesday, WWF-Philippines said it has identified 458 individual whale sharks in the country since 2007, with 377 of them found in Donsol.
Cebu was a far second with 54 butandings identified, 14 in Leyte and the rest in Bohol, Palawan, Albay and Batangas.
With the support of WWF-Denmark, WWF-Philippines teamed up with Australia-based ECOCEAN, the Hubbs Sea World Research Institute and Banco de Oro Unibank to catalogue the country’s whale sharks. The partnership provides researchers with both population pegs and migratory data to guide conservation efforts not just for whale sharks – but for all migratory pelagic species.
Sporting waterproof digital cameras, trained WWF skin divers snap photos of a spot right above each shark’s pectoral fins, behind its gill slits. The photos are fed into a computer which uses a program to triangulate each shark’s unique spot configuration. The data is then uploaded to the web-based ECOCEAN library.
Unless it is a new individual, the library shows researchers when and where the shark was last encountered. Since 2003, ECOCEAN has catalogued 3,822 individual sharks from places as far as Mexico, Mozambique and the Galapagos Islands.
“Photo-identification is a non-invasive approach for identifying sharks,” said Dave David, a whale shark researcher at WWF-Philippines. “The library uses the whale shark’s distinct patterns, plus information on scars, sex and size to identify individuals.”
To complement the photo-identification drive, 29 whale sharks were also affixed with detachable GPS satellite tags designed to pop to the surface after several months of data collation. Four sharks were tagged in May 2007, 10 more in May 2009 and 15 in April 2010, according to the WWF.
"The results suggest that most tagged whale sharks keep to 200 kilometers of Donsol. Three however, swam east to the Philippine Sea, with one more swimming as far north as Taiwan. All spent most of their time below 50 meters, rarely rising to the surface to feed," the group said in the statement.
David said the results suggest that whale sharks are "highly mobile, transient foragers which recognize no country or territorial boundary as their own."
"The distribution of whale sharks and other large filter-feeders also indicate the presence of plankton and the overall health of our oceans,” he added.
For years, Donsol has been identified as a whale shark hotspot, hosting one of the largest aggregations of whale sharks on Earth.
Other large aggregations include Ningaloo Reef in Australia with 808, Mexico with 812 and Mozambique with 624.
Through continued research, David and other WWF volunteers hope to generate an accurate peg of the country’s migratory and resident whale shark population.
“Long days at sea are worth it, considering the immense scientific, ecological and economic value that whale sharks bring people,” David said.
“Even after years of research, there’s still so much we have to discover – where they feed, mate and give birth. Our work continues, which is just as well because diving with these gentle giants is pure magic.”