National Committee on Marine Sciences (NCMS)
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- MPA-FishMApp – a citizen science app that simplifies monitoring of coral reef fish density and biomass in marine protected areasAbesamis, Rene; Balingit, Rodel; de Castro, Romulo; Aguila, Raphael Nelo; Cabiguin, Maryjune; Villagracia, Julius; Susmeña, Marynoll; Montemar, Mario Neil; Yocor, Antonio (National Fisheries Research and Development Institute, 2022-12)Monitoring changes in fish density and biomass inside marine protected areas (MPAs) through fish visual census (FVC) can determine if MPAs are achieving their goal of promoting fish population recovery. Simplified FVC methods have been developed for citizen scientists to enable them to monitor fish populations in MPAs. However, MPA monitoring programs led by local stakeholders remain rare and difficult to sustain due to technical barriers related to FVC data management. Here, we describe and evaluate a novel online app called MPA-FishMApp, which we developed to help stakeholders of MPAs that protect coral reefs in the Philippines efficiently store, analyze, and visualize FVC data. MPA-FishMApp is coupled to a simplified FVC method wherein the observer records only 21 reef fish species groups during surveys. The app provides a simple data entry interface, cloud storage, and algorithms to estimate fish density and biomass. Spatial and temporal trends in fish density and biomass can be instantaneously visualized in the app based on relative importance to fisheries. Field testing suggested that the MPA-FishMApp methodology (simplified FVC and app) is sensitive enough to detect qualitative patterns showing differences in density and biomass that may develop between MPAs and fished sites, especially in fishes that are highly important to fisheries. However, users must have sufficient training and experience in simplified FVC to produce reliable data. MPA-FishMApp may help reverse the lack of monitoring in MPAs across the Philippines and offers an accessible, transparent, and auditable venue for collaboration between citizen scientists and professional scientists.
- Spatial and short-term temporal patterns of octocoral assemblages in the West Philippine SeaLalas, Jue Alef A.; Lim, Romina Therese S.; Cabasan, Joey P.; Segumalian, Christine S.; Luciano, Rhea Mae A.; Valino, Darryl Anthony M.; Jacinto, Melchor R.; Arceo, Hazel O.; Baria-Rodriguez, Maria Vanessa (Frontiers Media SA, 2022-01-06)Octocorals are relatively understudied than other coral reef organisms despite their ecological and economic values. The Philippines is known to have high marine biodiversity, but information on octocorals is lacking. This study investigated spatial and temporal variations in the assemblage of octocorals in selected reef sites in the West Philippine Sea (WPS)- the Kalayaan Island Group (i.e., Pag-asa, Sabina, Lawak, and Northeast Investigator) and Ulugan in 2017 and 2019. Results showed high octocoral taxonomic richness (at least 10 families) in the study sites. Mean percent octocoral cover in WPS was 5.35% SE ± 0.55, with Sabina having the highest octocoral cover in both years. Significant differences in octocoral cover were observed among sites in both years, but among-station differences were only observed in 2017. Octocoral assemblage also differed among sites in both years (ANOSIM: R > 0.5, p < 0.05), wherein different octocoral taxa dominated in different sites. In particular, variations were driven by high cover of holaxonians, nephtheids, and coelogorgiids in Sabina, and clavulariids, tubiporiids, and xeniids in Northeast Investigator in 2017. In 2019, significant variations were driven by high cover of helioporiids in Pag-asa, while Sabina had higher abundance of holaxonians, nephtheids, alcyoniids, and xeniids. Short-term temporal variation on octocoral cover in monitoring stations in Pag-asa was not observed (Kruskal-Wallis, p > 0.05), although the overall mean octocoral cover increased from 1.23% ± SE 0.47 in 2017 to 2.09% SE ± 0.37 in 2019. Further, there was no significant change in the octocoral assemblage in Pag-asa between years (ANOSIM, R = 0.11, p = 0.07). This study highlights high octocoral taxonomic richness in the WPS relative to other sites in the Indo-Pacific Region and provides baseline information on the octocoral assemblages, which can be useful for future ecological studies and marine biodiversity conservation efforts.We would like to thank the Department of Agriculture-Bureau of Fisheries and Aquatic Resources (DA-BFAR), Philippine Coast Guard (PCG), the Municipality of Kalayaan, and the Philippine Navy for their assistance and support during the research expeditions in the West Philippine Sea. We also thank Lovely Joy Heyres for assisting in the field collection and image analysis, and Kevin Yatco and Socorro Rodrigo for assisting in the satellite product processing. We also thank the valuable insights and suggestions given by the editor and reviewers of this journal that helped improve this manuscript.
- Nearshore to offshore trends in plankton assemblage and stable isotopes in reefs of the West Philippine SeaYñiguez, Aletta T.; Apego, Gianina Cassandra May; Mendoza, Norman; Gomez, Norchel Corcia; Jacinto, Gil S. (Frontiers Media SA, 2022-01-25)Coral reefs are typified by their benthic components, and reef diversity and productivity are traditionally ascribed to the symbiotic association between corals and zooxanthellae, and other macroalgal forms. Less understood is the role of plankton and adjacent pelagic areas in contributing to reef productivity. Half of the reef benthos are filter or particle feeders, while a significant proportion of reef fishes are planktivorous. These organisms can serve as bridges between adjacent oceanic areas to the reef proper, and the pelagic and benthic realm. Here, we investigate the plankton trophic dynamics in two reef systems in the West Philippine Sea. Physico-chemical data, phytoplankton and mesozooplankton samples were collected from stations spanning offshore to reef areas per site. These were subjected to microscopic and stable isotope analysis to determine variability in plankton distribution, phytoplankton and zooplankton interactions, and gain insights into the trophic dynamics and productivity of reefs. Results showed distinct variations in plankton biomass and assemblage from offshore to reef areas, as well as between the reef systems. Phytoplankton distributions pointed toward filtering out of cells across the fore reef and reef flat areas, while mesozooplankton distributions could be mediated more by other factors. Isotopic signatures of δ13C and δ15N indicated the influence of different nutrient sources for phytoplankton and that mesozooplankton relied only partly on phytoplankton for food in most areas of the reefs. The mesozooplankton likely also obtain food from other sources such as the microbial and detrital pathways. More in-depth spatio-temporal studies on these bentho-pelagic interactions are recommended, which can provide more robust estimates of the trophic dynamics of these reefs that are situated in important fishing grounds and key biodiversity areas.We thank Cesar Villanoy and the Physical Oceanography laboratory for organizing the research cruise, the Philippine Navy and the BRP Gregorio Velasquez (AGR 702) for the help in sample collection during the research expedition conducted in the Kalayaan Group of Islands in 2017. We also thank the Department of Science and Technology – Philippine Nuclear Research Institute for the collaboration in conducting the stable isotope analyses, John Kristoffer Q. Andres for identifying the zooplankton samples, and John Michael N. Aguilar for analyzing the samples for chemical parameters.
- Two hidden mtDNA-clades of crown-of-thorns starfish in the Pacific OceanYasuda, Nina; Inoue, Jun; Hall, Michael R.; Nair, Manoj R.; Adjeroud, Mehdi; Fortes, Miguel D.; Nishida, Mutsumi; Tuivavalagi, Nat; Ravago-Gotanco, Rachel; Forsman, Zac H.; Soliman, Taha; Koyanagi, Ryo; Hisata, Kanako; Motti, Cherie A.; Satoh, Noriyuki (Frontiers Media SA, 2022-04-27)Recurring outbreaks of crown-of-thorns starfish (COTS) severely damage healthy corals, especially in the Western Pacific Ocean. To obtain a better understanding of population genetics of COTS and historical colonization across the Pacific Ocean, complete mitochondrial genomes were sequenced from 243 individuals collected in 11 reef regions. Our results indicate that Pacific COTS (Acanthaster cf. solaris) comprise two major clades, an East-Central Pacific (ECP) clade and a Pan-Pacific (PP) clade, separation of which was supported by high bootstrap value. The ECP clade consists of COTS from French Polynesia, Fiji, Vanuatu and the Great Barrier Reef (GBR). The Hawaii population is unique within this clade, while California COTS are included in EPC clade. On the other hand, the PP clade comprises multiple lineages that contain COTS from Vietnam, the Philippines, Japan, Papua New Guinea, Micronesia, the Marshall Islands, GBR, Vanuatu, Fiji and French Polynesia. For example, a lineage of the PP clade, which has the largest geographic distribution, includes COTS from all of these locations. These results suggest two alternative histories of current geographic distributions of COTS in the Pacific Ocean, an ECP clade ancestry or Western Pacific clade ancestry. Although further questions remain to be explored, this discovery provides an evolutionary context for the interpretation of COTS population structure which will aid future coral reef research in the Pacific Ocean, and ultimately improve reef management of COTS.We thank the following people for their help with sample collection: Dr. Hugh Sweatman and the AIMS Bioresources Library for GBR samples, Dr. Molly Timmers for Hawaiian samples, Geoff Jones and Jeff Kinch for Papua New Guinean samples, Monal Lal for Fijian samples, Christina Shaw for Vanuatu samples, Hoang Dinh Chieu for Vietnamese samples, and Hiromitsu Ueno for Japanese samples. The DNA Sequencing Section and IT section of OIST are acknowledged for its expert help with genome sequencing and bioinfomatic analysis. Last, but not least, we acknowledge the traditional owners of the lands and sea country on which this research took place.
- Submerged reef features in Apo and Tubbataha Reefs, Philippines, revealed paleo sea-level history during the last deglaciationMunar, Jeffrey C.; Aurelio, Mario A.; Dumalagan, Edwin E.; Tinacba, Erin Joy C.; Doctor, Ma. Angelique A.; Siringan, Fernando P. (Springer, 2024-02-27)The morphology of coral reefs provides an effective benchmark of past sea levels because of their limited vertical range of formation and good geologic preservation. In this study, we analyze the seafloor morphology around two atolls in the Philippines: Tubbataha Reef, in Palawan, and Apo Reef, in Occidental Mindoro. High-resolution multibeam bathymetry to a depth of 200 m reveals seafloor features including reef ridges and staircase-like terraces and scarps. Depth profiles across the reefs show terraces formed within six and seven depth ranges in Tubbataha Reef and in Apo Reef, respectively. These were further observed through a remotely operated vehicle. The terraces and scarps are interpreted as backstepping reefs that were drowned during an overall rise in sea level from the Last Glacial Maximum (LGM). Terraces are used as indicators of paleo sea level and the separation between terraces as the magnitude of sea-level rises coeval with meltwater pulse events during the last deglaciation. The pattern for both Apo and Tubbataha reefs indicates subsidence, consistent with the absence of Holocene emergent features and their atoll morphologies. Subsidence of up to 17 m since the LGM in Apo Reef is mainly attributed to the downbowing of the crust toward Manila Trench. In Tubbataha Reef, subsidence of up to 14 m is attributed to the continuous cooling of the volcanic crust underlying the atoll. These can be used to fill gaps in the tectonic history of the study sites from the last deglaciation.This study was funded by the Department of Science and Technology–Philippine Council for Agriculture, Aquatic and Natural Resources Research Development (DOST-PCARRD) Geophysical Coral Mapping Project and Acquisition of Detailed Bathymetry for Coastal Erosion Management Project both under F. P. Siringan, and National Assessment of Coral Reef Environment (NACRE) Project under Hazel Arceo. We would like to mention, in particular, Dominic Jone Cabactulan, Timothy Quimpo, Ronald Olavides, Mary Ann Calleja, Patrick Cabaitan, and Cesar Villanoy who were members of the project team. We thank the Tubbataha Management Office, Sablayan Local Government Unit, and Department of Environment and Natural Resources for the work permits and logistical help during the surveys.
- Multi-scale coral reef and seascape habitat variables combine to influence reef fish assemblagesSievers, Katie T.; McClure, Eva C.; Abesamis, Rene A.; Russ, Garry R. (MDPI, 2024-04-15)While benthic characteristics of coral reef habitats are a major driver of the structure of coral reef fish assemblages, non-reef habitats adjacent to coral reefs (e.g., mangroves, seagrass beds, and macroalgal beds) can affect reef fish assemblages. Here, we investigate how reef fish assemblages respond to local-scale benthic habitats within a coral reef and larger-scale adjacent seascape features (habitats within 500 m of coral reefs) on Siquijor Island in the Philippines. We examined an abundance of species for the entire reef fish assemblage and within the assemblages of parrotfishes (subfamily Scarinae) and wrasses (family Labridae). Five distinct habitat types were identified in a cluster analysis, which incorporated benthic characteristics within coral reefs and habitats adjacent to coral reefs. We found that the diversity and structure of coral reef fish assemblages were affected by benthic characteristics within coral reefs and also by benthic habitat types adjacent to coral reefs. Individual species responses and juveniles of certain species demonstrated uniquely high abundances in habitat clusters characterized by the non-reef habitats surrounding coral reefs. Considering coral reef habitats and adjacent non-reef habitats as a holistic, interconnected seascape will provide better estimations of the drivers of the structures of coral reef fish assemblages.This work would not have been possible without the invaluable contributions of the late Angel Alcala. His groundbreaking work paved the way for research in the Philippines, and his lifelong dedication to exploring and protecting the natural ecosystems of his country granted us access to crucial research sites. He also provided essential logistical and administrative support, significantly enhancing the feasibility of this project.
- 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.
- Fish and benthic communities in an offshore and well-managed coral reef after bleaching disturbance in the PhilippinesQuimpo, Timothy Joseph R.; Requilme, Jeremiah Noelle; Gomez, Elizabeth; Sayco, Sherry Lyn; Dumalagan, Edwin E.; Siringan, Fernando P.; Conaco, Cecilia; Cabaitan, Patrick C. (Springer, 2023-08-29)Climate change is perhaps the greatest threat to coral reefs worldwide. However, there is spatial variation in the extent and severity of this disturbance, with offshore and well-managed reefs presumed to be less vulnerable to anthropogenic disturbance. Here, fish and benthic communities at the offshore and well-managed reefs of Apo Reef Natural Park, Philippines, were examined during a bleaching disturbance in 2016 and reassessed 2 (2018) and 3 years (2019) after using scuba surveys. Results showed that benthic communities varied more strongly with year attributed to changes in the benthic cover of coral. These changes were influenced by site, with some sites experiencing coral loss of 41–48%, while other sites exhibited minimal changes. Site differences in coral loss may be associated with coral cover, with sites that had high coral cover prior to bleaching incurring larger loss of coral cover. Fish communities varied more with sites and was associated with differences in the predominant benthos. The stability of fish communities with year despite coral loss may be attributed to the minimal loss of coral cover at some sites. For sites that experienced high losses of coral cover, the presence of alternative and deeper habitats may have provided shelter and food for more mobile fishes maintaining taxonomic composition within sites. This study shows that bleaching disturbance circumvents effective management, but impacts are variable even at small (≤ 3 km) spatial scales. Benthic community composition and presence of alternative habitats potentially alleviate the negative impacts of bleaching on reef fish diversity and abundance.We are grateful to the laboratory assistants F Castrence, R de Guzman, B Gabuay, R Valenzuela and K Adolfo for their assistance in the fieldwork. We thank the comments and criticisms of two anonymous reviewers that greatly improved the content of this manuscript.
- Decadal stability in coral cover could mask hidden changes on reefs in the East Asian SeasChan, Y. K. S.; Affendi, Y. A.; Ang, P. O.; Baria-Rodriguez, M. V.; Chen, C. A.; Chui, A. P. Y.; Glue, M.; Huang, H.; Kuo, C-Y.; Kim, S. W.; Lam, V. Y. Y.; Lane, D. J. W.; Lian, J. S.; Lin, S. M. N. N.; Lunn, Z.; Nañola, C. L.; Nguyen, V. L.; Park, H. S.; Sutthacheep, M.; Vo, S. T.; Vibol, O.; Waheed, Z.; Yamano, H.; Yeemin, T.; Yong, E.; Kimura, T.; Tun, K.; Chou, L. M.; Huang, D. (Springer, 2023-06-10)Coral reefs in the Central Indo-Pacific region comprise some of the most diverse and yet threatened marine habitats. While reef monitoring has grown throughout the region in recent years, studies of coral reef benthic cover remain limited in spatial and temporal scales. Here, we analysed 24,365 reef surveys performed over 37 years at 1972 sites throughout East Asia by the Global Coral Reef Monitoring Network using Bayesian approaches. Our results show that overall coral cover at surveyed reefs has not declined as suggested in previous studies and compared to reef regions like the Caribbean. Concurrently, macroalgal cover has not increased, with no indications of phase shifts from coral to macroalgal dominance on reefs. Yet, models incorporating socio-economic and environmental variables reveal negative associations of coral cover with coastal urbanisation and sea surface temperature. The diversity of reef assemblages may have mitigated cover declines thus far, but climate change could threaten reef resilience. We recommend prioritisation of regionally coordinated, locally collaborative long-term studies for better contextualisation of monitoring data and analyses, which are essential for achieving reef conservation goals.
- Multiple severe storms revealed by coral boulders at Pasuquin, northwestern Luzon, PhilippinesGong, Shou-Yeh; Liu, Sze-Chieh; Siringan, Fernando P.; Gallentes, Adonis; Lin, Han-Wei; Shen, Chuan-Chou (Elsevier, 2022-11-15)Over 30 meter-sized coral boulders are scattered 45–140 m away from the edge and above high tide on a Holocene reef flat at Pasuquin, northwestern Luzon, Philippines. The boulders are overturned or tilted as indicated by the framework fossil corals in them, but have the same lithology as those along the reef edge and thus were likely broken off from there. The dimensions of boulders larger than 3 m were calculated from 3D models constructed by photogrammetry. Their volumes range from 10 to 53 m3. Assuming 2.1 g/cm3 for wet density, weights of boulders would range from 21 to 110 metric tons. Boulders of such size and weight can't be moved by normal waves, and thus must have been dislodged by extreme wave events (EWEs). Small and well-preserved corals found on the surface of seven boulders were collected for 230Th dating to reconstruct the timing of displacement. The ages of corals are 1781.6 ± 1.9, 1903.4 ± 2.7, 1945.8 ± 1.2, 1956.9 ± 1.2, 1956.75 ± 0.99, 1978.1 ± 1.5 and 2002.78 ± 0.88 CE, respectively. These ages are considered to constrain the timing of boulder displacement from the reef edge. We propose that typhoon-induced EWEs were responsible for the displacement of these boulders at Pasuquin.