Lem conducting "photo ID" studies in southern Tañon Strait, identifying individual dolphins through scars, shape, and unusual pigments in dorsal fins. Photo courtesy of the UPD-IESM Marine Mammal Research and Stranding Laboratory

Marine mammals—such as whales, dolphins, dugongs—are descended from ancestors that lived entirely on land. Fleeing from terrestrial competition, they turned to the waters and the vast resources of its depths. The Philippines is rife with marine mammals, a fact confirmed by stranding incidences—more than 800 recorded since 2005—exceeding the normal numbers in the region.