Monday, April 5, 2010

Whale Shark Stranding in Maribulan, Alabel, Sarangani Province

A whale shark stranding was reported by the Provincial Governor’s Office in the shores ofSACI Wharf, Maribulan, Alabel, SaranganiProvince last March 5, 2010 at around 2:30 p.m. The staff of the Environmental Conservation and Protection Center (ECPC), together with the Provincial Environment and Natural Resources Office (PENRO), went to respond to the stranding and confirm the identity of the organism.


The 4.75-m long, juvenile butanding, as what whale sharks are locally known, was unintentionally caught and dragged ashore in a 300-m net, which was laid perpendicular to the shore at a depth of approximately 6 feet. Close inspection of the animal revealed a number of scratches in some parts of its body, especially on the dorsal portion. It was also noted that there were at least three scars found in dorsal fin and a triangular cut was observed at tip of its tail. Since the butanding was still alive and can function normally, the team decided to tow it (with the help of some locals) to deeper water for release to the open sea. Moreover, it was also noted that there were at least three documented whale shark strandings/sightings in the area within the past four years. Sightings/stranding in the area may have been caused by its feeding behavior – they are often found in areas of where food is abundant. A previous study during a sighting revealed that the water in the area have high plankton content, especially that of krill (a shrimp-like crustacean), which is one of the preferred diet of a butanding. The ECPC team shall schedule yet a monitoring regime in order to pinpoint the main (and other) reasons for the stranding/sighting.

Whale sharks (Rhincodon typus) were among the largest animal in the planet and is considered as the largest fish in the world, growing up to 20 meters and weigh of up to 34, 000 kilograms. They are characterized by a massive and long body, with white or yellow round spots (which are now used for identification and monitoring), and their skin is considered as the thickest among all animals. Although a butanding has a wide and big mouth, it only feeds by filtering planktons through a fine mesh in their gill-rakers. These gentle giants pose no harm to human; however, whale sharks are now threatened and are classified by the World Conservation’s Union (IUCN) as ‘vulnerable to extinction’[1].

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1 Tim Winton. ECOCEAN Brochure. www.whaleshark.org