Small villages along the Bohol and Sulu Sea have traditionally hunted Mobulas for over a century. These creatures were once believed to be so common that people could walk on their backs to cross between islands.
In the 70s, these local fisheries replaced their artisanal catch methods with industrialized techniques. Kilometers-long nylon driftnets and commercial engines took the place of traditional hand-tossed harpoons and sail and paddle propulsion.
This modernization of fishing practices facilitated an increase in catch to the point that the local coastal fishing grounds were no longer able to support the industry. This caused fishers to venture further and further offshore to meet the ever-rising demand for mobula byproducts.
This transformation of the local fisheries from traditional to industrial set-ups was driven by an increase in demand by both local and overseas markets. Local people developed a taste for mobula meat while the traditional Chinese medical market sought out ever-increasing quantities of the rays’ dried gill rakers.
Manta and devil rays were targeted by fisheries in the Philippines until as recently as 2017. While the oceanic manta ray has technically been protected in the country since 1998, the overlapping occurrence of these species, the non-selective fishing methods used by local fishers, and the lack of enforcement by the authorities meant that the oceanic manta, along with other mobula, were still caught in large numbers.
Manta and devil rays are susceptible to dramatic population declines and thus are unable to sustain these intense fishing pressures. This is because they are k-selective species characterized by slow growth, late sexual maturation (5-9 years), low fecundity (typically giving birth to a single pup every 2-5 years), and long gestation periods (12 months).
In 2017, all species of mobula were listed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). This is an international agreement between governments that seeks to ensure that the trade of wild species does not threaten their survival.
In the Philippines, this resulted in a national ban on the catching and selling of all mobula rays and their byproducts, in accordance with the Amended Philippine Fisheries Code (RA 8550). This code ensures that the catch of any species listed under CITES Appendices is prohibited until the sustainability of the harvest is scientifically proven.
Illegal targeted fishing and incidental bycatch;
Chemical pollution, especially oil spills
Solid pollution including microplastics
Unregulated diving tourism in critical habitats such as cleaning stations and aggregations sites;
Habitat degradation and destruction in key habitats such as unsustainable coastal development, boat anchoring, ghost nets, dynamite and cyanide fishing, and trawling over cleaning stations;
Boat and ship traffic.
Scientific study takes a deeper look into the reproduction of mobulid rays in the Philippines
A new scientific publication by Large Marine Vertebrates Research Institute Philippines (LAMAVE) was lead by researcher Joshua Rambahiniarison and aimed to determine life history and reproductive parameters for several mobulids caught in the Philippines to provide vital information on the sustainability of the exploitation and consumptive use of these megafauna, at the country level and worldwide.