Mobulid rays (Family Mobulidae), commonly known as 'devil rays', comprise the genus Mobula and the genus Manta. Five species have been recorded in the Bohol Sea, the spine tail devil ray (Mobula japanica), bent fin devil ray (Mobula thurstoni), sickle fin devil ray (Mobula tarapacana), and the iconic oceanic manta ray (Manta birostris) and reef manta ray (Manta alfredi). All these species are listed as 'vulnerable' within the South East Asia region under the IUCN Red List, with the exception of the sickle fin devil ray, data deficient. Currently, these pelagic animals face significant threat in the Philippines as century-old mobulid fisheries thrived around the Bohol Sea. Nowadays, with the collapse of most of these fisheries, Jagna, in Bohol Island, remains one of the last and the largest mobulid fishery in the country. While M. birostris has been protected in the Philippines since 1998, the species is still regularly caught, and no protection or national fishery regulation exist for the other species.
A LAMAVE team, lead by a Principal Investigator (PI), is studying priority research questions on the ecology and biology of mobulid rays in a landing site. Current studies are focusing on the description of life-history and reproductive parameters, which are fundamental to improving demographic models and support fishery management plans. The possibility of over-fishing needs to be examined and addressed, while alternative livelihoods for the locals communities of this island need to be established, and awareness raised. One of LAMAVE’s cornerstone is to work with the local community in developing and promoting alternative livelihoods to help them overcome their fear of losing their income source.
Teamwork is essential during and after field work. The team may work as a single unit. The studysite is the fishery landing site, volunteers have to be able to deal with dead animals and bloody circumstances. We are on site from when the first boat arrives until the final boat returns, thus you may sometimes be ready to spend hours waiting.
Volunteer duties include:
- Collecting morphometric data
- Equipment maintenance
- Tissue sample collection and processing
- Aiding with coinciding research projects
- Photo documentation and sorting
- Data entry
- GPS deployment and downloading
- Assisting in information, education & communication (IEC) campaigns
Morphometric and anatomic data – measurements and morpho-anatomic data are recorded from specimens landed every day, with a range of measurements being taken for each animal. It includes measuring individuals but also collecting internal organs. The Samples collection – Samples may be required from some of the measured animals, depending on the desired research outcomes. Samples can include tissues, parasites, stomach content and specific organs. A tissue sample from any Manta spp or M. tarapacana caught is always taken to be stored at the project base. Process tissue samples collected Photos – Photo identifications of the specimens recorded, photo of interests, proofs and documentations are taken systematically in the field. Data Input – Upon returning to the project base, data from the day are inputted to the database, photos are sorted. Accuracy of Data – Accuracy in transcribing data is essential, as this data that will be analyzed and implemented into LAMAVE scientific literature. Any mistakes will compromise the accuracy of our research. The GPS deployment – A GPS is deployed daily on each boat going out fishing. Equipment maintenance – clean, organize, prepare the material after/before the field. It is the responsibility of each of the team member to handle equipment carefully, especially considering field conditions. Salty water, sun, high humidity level, and high temperature, damage equipment faster. Education and Communication – Organize and coordinate events with the community such as beach cleanup or documentary showin.