Baited Remote Underwater Video (BRUV) Technique Enhances Seagrass and Fish Assemblage Assessments in Palawan’s MPAs

A recent study utilizing Baited Remote Underwater Video (BRUV) has provided valuable insights into fish assemblages and seagrass ecosystems in Marine Protected Areas (MPAs) and non-protected areas of Busuanga and Roxas, Palawan. This research is part of the Seagrass Ecosystem Services Project, funded by the International Climate Initiative (IKI) and led by the Convention on Migratory Species Office of Abu Dhabi under the Dugong MOU. It is being implemented in six countries across the Asia-Pacific region, including the Philippines, where Community Centred Conservation (C3) Philippines, Inc. is one of the project partners.

Seagrass ecosystems, known for their essential role in marine biodiversity, are being closely studied in the coastal waters of Busuanga and Roxas, Palawan, with the use of Baited Remote Underwater Video (BRUV) technology. A recent study led by C3 Philippines, in partnership with local government units, explores the impact of seagrass meadows on fish assemblages in both Marine Protected Areas (MPAs) and adjacent non-protected zones (Figure 1) . The BRUV survey, conducted across multiple sites, offers a non-intrusive method to observe marine life, providing crucial data on fish species composition, abundance, and the overall health of seagrass meadows in the region.  The project aims to fill knowledge gaps in marine conservation and provides vital data for future marine management.

Figure 1. Study Sites in Busuanga (Calawit and Ocam-ocam), and Roxas (Johnson Island and Green Island), Palawan, Philippines.
An underwater shot recorded during the Baited Remote Underwater Video (BRUV) survey. The camera captures a view of the lush seagrass ecosystem, where the bait canister is set in place to attract marine species for monitoring. This footage is part of the efforts to assess biodiversity and habitat health in the surveyed marine area.

Seagrass ecosystems play a pivotal role in supporting marine biodiversity and maintaining ecological balance. They provide habitat and nursery grounds for various fish species, contribute to carbon sequestration, and help protect coastlines from erosion. In Palawan, seagrass meadows are essential to the marine ecosystems of both Busuanga and Roxas, but comprehensive assessments of these habitats and the fish communities they support have been limited. “The ecological importance of seagrass meadows cannot be overstated; they support both marine biodiversity and local livelihoods,” remarked Mr. Leo Magbanua, one of the community partners and MPA Manager in Roxas, Palawan. These results underscore the need for informed management strategies to protect these vital habitats.

The study deployed a total of 60 BRUV drops during both wet and dry seasons, supplemented by the analysis of 300 quadrats placed within seagrass beds. Video footage captured through the BRUV system allowed the team to document fish behavior, identify species, and classify them into different trophic levels, revealing patterns of fish diversity and abundance across the different areas.

C3PH together with the technical partner and MPA Manager of the study site deploy the Baited Remote Underwater Video (BRUV) system into the water to monitor marine biodiversity. The BRUV setup, designed to attract and record marine life, plays a crucial role in assessing species richness and ecosystem health in the area.

Preliminary findings showed that the BRUV technique was highly effective in sampling fish communities within seagrass habitats. A variety of species were recorded, including several economically valuable ones such as rabbitfish, emperors, groupers, and snappers, indicating potential hotspots for sustainable fishing activities. These results not only highlighted the ecological importance of seagrass meadows but also underscored the need for informed management strategies to protect these habitats.

Seagrass ecosystems in the study areas were found to be diverse, with eight distinct species documented across Busuanga and Roxas such as Cymodocea rotundata, Halophila ovalis, Thalassia hemprichii, Halodule uninervis, Halodule pinifolia, Syringodium isoetifolium, Enhalus acoroides, and Cymodocea serrulate. The distribution of these species varied across the sites, driven by factors such as water depth, light availability, sediment type, and water quality. The study’s findings suggest that seagrass beds in both MPAs and non-protected areas continue to provide critical ecological services, supporting both marine biodiversity and local livelihoods.

Despite the study’s successes, several challenges were encountered. Adverse weather conditions, including typhoons and strong waves, often delayed fieldwork and affected the ability to deploy BRUVs in the water safely. “There were times when rough seas and high winds made it impossible to conduct our surveys as scheduled,” explained one of the programme officers. In addition to these logistical issues, the team had to contend with changing environmental conditions, such as fluctuating water quality, which influenced the visibility and accuracy of the video footage.

Nevertheless, the BRUV technique proved adaptable and efficient for use in the region, offering a non-invasive alternative to traditional survey methods. By capturing detailed underwater footage, the BRUV system allows for repeatable data collection without the need for divers or intrusive equipment, minimizing human impact on marine life.

C3 PH staff member John Rey Padilla and technical partner Alex Bartlett from Project Seagrass collaborate during a Baited Remote Underwater Video (BRUV) survey. The team is pictured in shallow waters, preparing to deploy the BRUV equipment used to monitor marine biodiversity and assess seagrass ecosystem health. They are reviewing data on a mobile device to ensure precise placement of the equipment for optimal results.

The data gathered through this study will contribute to the ongoing conservation efforts in the area and help shape policies aimed at protecting seagrass ecosystems. Potential recommendations include enhancing MPA coverage in critical areas, enforcing existing regulations on sustainable fishing practices, and establishing long-term monitoring programs to track the health of seagrass meadows and their associated fish populations.