This report summarises the findings of data collected from January to December 2018, as well as historical data collected since 2016 through the reef monitoring activities carried out by People and the Sea in the Municipality of Daanbantayan, Province of Cebu, Philippines. The collected data include benthic cover, hard coral lifeforms, coral impacts and stressors, coral recruitment, density and diversity of reef associated and commercially important fish species, as well as abundance of invertebrate species that are indicators of reef health.
As most of coral reefs worldwide, reefs in the Philippines show declining coral cover due to a variety of stressors. Most significant among these are overexploitation, direct impact of human activities and climate change. The coral reefs of Malapascua are prone to natural threats (typhoon, predation) as well as anthropogenic impacts such as destructive fishing practices, damages by touristic activities and water pollution. The results presented in this report aim to describe the health of Malapascua reefs and better understand how they respond to the different stressors.
Percentage hard coral cover across all surveyed sites is found to have increased since previous years to a current value of 33.7 (± 3.7) %, which represents an increase of 6.3% compared to the survey period of 2016. The coral impacts survey results show high occurrence of physical damages (8.9 ± 1.5 occurrences per 100m2), predation (6.0 ± 1.1 per 100m2) and recently killed corals (6.1 ± 1.5 per 100m2). The mean fish density is slightly higher than the previous year, with a current value of 0.36 (± 0.03) fish/m2 representing an increase of 6.7% compared to 2017. However, commercial fish species and large fish occur at very low abundance (0.044 ± 0.013 commercial fish/m2). The abundance of coral predators, calculated from 100m2 transect belts, is higher in 2018 than in previous years, with +0.27 Acanthaster planci, +5.47 Drupella spp. and +5.01 Coralliophylia violacea per 100m2 in the three-years period. This drastic increase is related to the increase of coral cover, but may negatively impact reef health if the density of predators raises above sustainable levels (i.e. when the rate of coral regeneration becomes lower than the feeding rate of their predators).
Overall, the results may indicate a positive trend of coral recovery from previous damages caused by typhoons and human activities, although the low density and small sizes of exploited fish and invertebrate species still indicate overharvesting. Thanks to its long term monitoring programme, People and the Sea collects data that aims to support the sustainable use of marine and coastal resources. Our objective is to engage with Local Government Unit (LGU) and the community of Malapascua to work together toward a community-based marine resource management and conservation model.