Rare Megamouth shark found in Philippines

Megamouth 41, caught in the Philippines. Photo credit Elson Aca/WWF Philippines.

April 2009. Fishermen based in Donsol in the Philippines were trawling for mackerel when they caught a strange large shark from a depth of approximately 200 metres. WWF's satellite tagging initiatives have already shown that pelagic filter feeders such as whale sharks and manta rays regularly prowl through the region. It was only a matter of time before something else was discovered.

The shark was brought to Barangay Dancalan for assessment. WWF Donsol Project Manager Elson Aca identified it as a megamouth shark.

Rarest known shark - Only 40 have ever been recorded
Rarest of all sharks, the megamouth (Megachasma pelagios) is a fairly recent scientific discovery, with just over 40 recorded encounters worldwide. The first specimen was caught off Oahu, Hawaii in 1976. So different was it from all other sharks that it necessitated the creation of an entirely new family and genus - prompting the scientific community to hail it as the 20th century's most significant marine find - rivalling the rediscovery of the coelacanth in 1938.

Megamouth 41
Megamouth 41, as named by the Florida Museum of Natural History, measured four metres and weighed an estimated 500 kilograms. Facial scars indicated a protracted struggle with the fishers' gill-nets while stomach contents revealed it was feeding on shrimp larvae.

The megamouth shark is so named for its enormous maw - almost a metre wide and lined with a brilliant silver band to attract planktonic prey in the depths. It is a poor swimmer which ranges sporadically throughout the Atlantic, Indian and Pacific Oceans. Males average four metres while females - which give birth to live young - grow to five.

Relatively little was known of their habits until megamouth 6 was fitted with a pair of ultrasonic transmitters and tracked for two days in 1990. The exercise indicated that the sharks spend the daytime in waters up to a kilometre deep and surface only at night to feed on plankton, small fish and jellyfish - usually at a depth of around 15 meters.

One of only 3 filter feeding sharks
Together with the basking and whale shark, the megamouth is one of only three filter-feeding shark species. It is classified globally by the IUCN as data deficient - but only because so few have ever been studied.

Megamouth 41, the rarest known shark species in the world, caught in the Philippines. Photo credit Elson Aca/WWF Philippines.

Contrary to Aca's advice, the megamouth was butchered - kinunot (shark sautéed in coconut milk) being a local delicacy of the Bicol Region. Fishermen say a similar shark was caught and eaten in the same area about 30 years ago. Fisheries Administrative Order 208 provides that after documentation, the carcass of all endangered marine animals should promptly be buried. WWF now remains on the lookout for further megamouth sharks.

Whale shark tourism
For over a decade, WWF has worked closely with the municipality of Donsol to establish and refine the now-famous community-based whale shark eco-tourism project, transforming the once sleepy town into one of the Bicol region's busiest revenue generators and earning it the title of butanding capital of the world. Current initiatives funded by WWF-Denmark and supported by the local government are led by Aca to establish whale shark migration routes and numbers through state-of-the-art photo-identification and satellite tagging techniques. Just last month WWF found and rescued a 15-inch baby whale shark - the world's smallest.

"The presence of two of the world's three filter feeding sharks warrants special attention for the Donsol-Masbate region," explains Aca. "Whale and megamouth sharks, manta rays, dolphins and other charismatic giants indicate that the region's ecosystem is still relatively healthy. By protecting megafauna, we help maintain the dynamic balance of our seas, and ensure the entire ecosystem's resilience and natural productivity."

WWF works with a host of partners to protect the megafauna of the Coral Triangle. The Philippines sits at the apex of this very special place, hailed by experts as the world's center for marine biodiversity.