National Committee on Marine Sciences (NCMS)
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- Spatial variation in the benthic community structure of a coral reef system in the central Philippines: Highlighting hard coral, octocoral, and sponge assemblagesLalas, Jue Alef A.; Manzano, Geminne G.; Desabelle, Lee Arraby B.; Baria-Rodriguez, Maria Vanessa (Elsevier, 2023-07)Coral reefs are complex habitats that contain very high biodiversity and provide different ecosystem services. In the Coral Triangle, however, various major benthic components are still understudied. This can limit our understanding of coral reef community dynamics, especially in the presence of a changing climate coupled with local disturbances (e.g., decreased water quality). This study describes the benthic community structure of an ecologically and economically important coral reef system in the central Philippines through characterizing the assemblages of three major components (hard corals, octocorals, and sponges) among sites and stations with varying environmental conditions (i.e., exposure to monsoons, water quality levels). Results reveal significant variations in the mean percentage covers of hard corals, octocorals, and sponges at the site and station levels (ANOVA, p < 0.05), with hard corals dominating in Site 1, which is more exposed to the southwest monsoon, and Site 3, which is an embayed and unexposed site with low water quality, while soft corals dominated in Site 2, which is more exposed to the northeast monsoon. Multivariate analyses also revealed significant variations in the benthic community structure at different spatial scales (ANOSIM, p < 0.05). Interestingly, even stations within a site had significant variations in community structure, with different taxa being dominant. This study highlights the importance of conducting more detailed analyses of understudied taxa (i.e., octocorals and sponges) during coral reef surveys to improve our understanding of coral reef community dynamics that is very important for management.
- Genus and size-specific susceptibility of soft corals to 2020 bleaching event in the PhilippinesBaran, Christine; Luciano, Rhea Mae A.; Segumalian, Christine; Valino, Darryl Anthony; Baria-Rodriguez, Maria Vanessa (Taylor & Francis, 2023-05-08)Soft corals are zooxanthellate sessile animals supporting various organisms in coral reefs. However, their populations are threatened by the impacts of ocean warming. Under thermal stress conditions, soft corals may experience mild to severe bleaching which may lead to death. Understanding soft coral bleaching responses highlights the importance in predicting how populations and diversity may be affected by changing climate scenarios. In this study, we examined the bleaching responses of the three dominant soft coral genera (Lobophytum, n = 1318; Sarcophyton, n = 116; Sinularia, n = 639 colonies) in the Bolinao-Anda Reef Complex (BARC), Pangasinan, north-western Philippines during the 2020 thermal stress event in terms of genus and colony size susceptibility, and zooxanthellae density. Degree heating week (DHW) data from 1986–2020 were obtained using remotely sensed data to determine thermal anomalies in the study sites. The maximum DHW (6.3) in 2020 occurred between July–August while bleaching surveys were done during October of the same year. The percentage of bleached portions in each colony was used to determine bleaching category: no bleaching (0%), moderately bleached (1–50%) and heavily bleached (>50%). Quantification of bleaching prevalence and susceptibility of colony sizes were determined by colony count and mean diameter measurements taken from quadrat photographs in October 2020. Haphazard tissue collection (∼3 cm) in each colony of three soft coral genera per bleaching category was done to quantify zooxanthellae density. Results showed that Lobophytum colonies had the lowest bleaching prevalence (41%), followed by Sinularia (66%) and Sarcophyton (78%). All colony size classes of the three genera were susceptible to bleaching. However, smaller colonies of Lobophytum (<15 cm), Sarcophyton (<5 cm) and Sinularia (<5 cm) showed less susceptibility than large colonies. Zooxanthellae density was significantly reduced in moderately and heavily bleached colonies. The results of this study highlight that bleaching susceptibility is genus specific, with Sarcophyton and Sinularia being more susceptible to bleaching than Lobophytum. Smaller colonies seemed to be less susceptible to bleaching than large-sized soft corals suggesting a differential thermal stress response. Spatial variations in bleaching prevalence were also found among reef sites with varying environmental conditions and thermal stress histories. This work provided initial observations on how bleaching affects soft corals. Further studies on soft coral community recovery are recommended to fully understand how these organisms perform after thermal stress events.
- Institutional dimensions of coral reef restoration in the PhilippinesMatorres, Dane Erlo; Fabinyi, Michael; Horigue, Vera; Novilla, Carmela Therese; Baria-Rodriguez, Maria Vanessa (Elsevier, 2024)While the Philippines is mostly known for its experiences on marine protected areas, local governments and non-government organizations are increasingly using coral restoration with the aim of rehabilitating degraded reef areas. Since the establishment of artificial reefs in the 1970s, the application, techniques and corresponding policy directives for reef restoration have evolved over time, and restoration has recently generated significant interest and investments from donors and government agencies. As the Philippines does not have a policy framework to support effective and sustainable practices for the use of different coral restoration techniques, the increase and unregulated use of restoration may result in unintended consequences and pose potential challenges to coastal management. To address this gap, we conducted a review of existing coral restoration policies, programs and projects across the country, with a focus on social, economic and governance aspects. The study collated existing published literature and unpublished information on coral restoration in the country, and conducted key informant interviews. The results show that coral restoration continues to increase, and that existing guidelines on coral restoration are poorly implemented and not widely understood among practitioners. While coral restoration projects reported ecological benefits, socio-economic impacts are limited. The evidence supports the need to review existing policies and contextualize coral restoration to contribute to relevant policy decisions about the restoration and protection of reefs.