The sighting of a newborn whale shark off the waters of Sorsogon and Masbate has provided proof that the areas serve as significant reproductive habitats for the endangered whale shark, locally called "butanding," according to a study.
A new scientific publication by the Large Marine Vertebrates Research Institute Philippines (LAMAVE) and the Bureau of Fisheries and Aquatic Resources-Region 5 (BFAR-Bicol Region) that was released on Monday, highlighted the importance of Donsol in Sorsogon and Ticao-Burias Pass in Masbate as a likely pupping ground and nursery area for the whale shark.
The study cited the discovery of a newborn whale shark, as well as the observation of whale sharks' mating-like behavior early this year.
On March 15, 2020 a free-swimming neonate whale shark was found in the shallow waters of Donsol by a member of staff from the Donsol Tourism Office.
Researchers from LAMAVE identified the whale shark as a male and measuring 60 centimeters (cm).
LAMAVE said it is smaller than the largest embryo, measuring 64 cm, reported in the only investigation of a pregnant female in Taiwan in the 1990s. This indicates that what was seen in Donsol was a newborn whale shark.
"Given their poor at-birth swimming abilities, it is likely that neonates remain fairly close to their birthing grounds, thus indicating Donsol and the Ticao-Burias Pass to be an important pupping ground and nursery area. It is the third neonate recorded in the area and it was the 1,930th individual whale shark to be identified in the Philippines," the experts said.
LAMAVE, who have been conducting research in Donsol since 2015 also underscored the value of local ecological knowledge of the Butanding interaction officers, who have, on occasion, reported mating-like behaviour by whale sharks where one individual was observed swimming below a second whale shark with its ventral side up.
The researchers also observed a large male whale shark lowering and "unfurling" its claspers or male reproductive organ.
The team concluded that these findings paired with previous reports of newborn whale sharks within the area, as well as the globally rare co-occurrence of adult males and females, "strongly suggests that Donsol and the Ticao-Burias Pass is an important reproductive habitat for the world’s largest fish."
"The Philippines is already a globally important area for whale sharks: the country’s waters host the second-largest known aggregation of whale sharks in the world. However, this new study suggests that for the first time the country, and specifically Donsol and the Ticao-Burias Pass, is a globally unique habitat for the whale shark and important for their reproduction," LAMAVE said.
"The continued protection of the area is paramount, and development within the area that may impact the species and/or the environment should be strictly regulated," it added.