An extremely rare megamouth shark was caught by Filipino fishermen, marking only the 41st time the species has been seen in the 33 years since its discovery and giving new insight into the elusive shark’s behaviour.
Fishermen based in Donsol were trawling for mackerel along the eastern coast of Burias Isle on the morning of 30 March when they caught a large shark from a depth of approximately 200 meters.
The shark was brought to shore in Barangay Dancalan in Donsol, Sorsogon and the Danish-funded WWF Donsol Project Manager Elson Aca immediately arrived to assess the haul and identified it as a megamouth shark – considered the world’s rarest shark. Megamouth 41, as the Florida Museum of Natural History has named the Donsol shark, measured four meters and weighed an estimated 500 kg.
For more than a decade, WWF has worked in Donsol to establish community-based whale shark eco-tourism, transforming the once sleepy town into one of the Bicol region’s busiest revenue generators. Current initiatives funded by WWF-Denmark and supported by the local government include researching whale shark migration routes and numbers through state-of-the-art photo-identification and satellite tagging techniques.
Last week’s megamouth encounter underscores the importance of the Donsol-Masbate region – part of the Coral Triangle – as a haven for rare marine life, according to WWF Philippines.
The discovery follows last month’s rescue by WWF of a 38 cm baby whale shark – considered the world’s smallest of its kind ever discovered.
“The presence of two of the world’s three filter feeding sharks warrants special attention for the Donsol-Masbate region,” Aca said. “Whale and megamouth sharks, mantra 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,” Aca said.
WWF works with a host of partners to protect the megafauna of the Coral Triangle which is considered a major center for marine biodiversity. WWF’s satellite tagging initiatives have already shown that pelagic filter feeders such as whale sharks and manta rays regularly prowl through the region.
The megamouth (Megachasma pelagios) is a fairly recent scientific discovery, with only 40 recorded encounters worldwide until the latest find. The first specimen was caught off Oahu, Hawaii in 1976. The discovery led to 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 and rivaling the rediscovery of the coelacanth in 1938. The megamouth shark is so named for its enormous jaw – almost a meter wide and lined with a brilliant silver band to attract planktonic prey. It has been found roaming throughout the Atlantic, Indian and Pacific Oceans. The males average four
meters while females – which don’t lay eggs, but give birth to live young offspring – can grow to five meters long.
Relatively little was known of their habits until researchers fitted a megamouth – the sixth one discovered – with a pair of ultrasonic transmitters and tracked it for two days in 1990. The research indicated that the sharks spend the daytime in waters up to one kilometre deep and surface only at night to feed on plankton, small fish and jellyfish – usually at a depth of around 15 meters.
Eight megamouth sharks, a fifth of all recorded encounters, have been caught in Philippine waters. Four were caught in Cagayan de Oro and one each in Negros, Iloilo and Cebu. Megamouth 41 is the first megamouth shark to have been caught in Luzon, which is the Philippines’ largest island.
Sadly and despite protests from Aca, the megamouth shark caught near Donsol was later butchered and eaten. Its stomach contents revealed it was feeding on shrimp larvae.
The waters around Donsol are part of the Sulu-Sulawesi Seas ecoregion, one of WWF’s Global 200 ecoregions — a science-based global ranking of the world’s most biologically outstanding habitats and the regions on which WWF concentrates its efforts. The also make up part of the Coral Triangle, a major area of marine biodiversity.
Leaders of the six nations that make up the Coral Triangle – Philippines, Indonesia, Malaysia, Papua New Guinea, Solomon Islands and Timor Leste –will meet on May 15 in Manado, Indonesia for the World Oceans Conference where they will announce a comprehensive set of actions to protect ecosystems and food security in the region.