National Committee on Marine Sciences (NCMS)
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- Insights into the environmental conditions contributing to variability in the larval recruitment of the tropical sardine Sardinella lemuruPata, Patrick R.; Yñiguez, Aletta T.; Deauna, Josephine Dianne L.; De Guzman, Asuncion B.; Jimenez, Cesaria R.; Rosario, Roselle T. Borja-Del; Villanoy, Cesar L. (Elsevier, 2021-07)The small pelagic fishery in the southern Philippines is one of the largest contributors to fisheries production in the country, and is dominated by the Bali sardine Sardinella lemuru. This species is a year-round spawner that has its peak spawning period during the northeast monsoon (NEM) months of November to February. However, there is still limited information on the conditions that affect this species’ survival during its early life history stages. Here, we attempt to discern the importance of temperature, prey density and advection on sardine larvae. The larvae were represented as passive particles that were released in known spawning grounds to simulate dispersal. The conditions the larvae experienced, namely, temperature and estimated prey density based on satellite chlorophyll-a values were recorded at each time step until the estimated recruitment age of 60 days. The temporal and spatial averaged conditions of recruited sardines showed that sardines spawned during the NEM months experienced higher chlorophyll-a, lower (more optimal) sea surface temperature, albeit higher advective loss, than sardines spawned during other months. Comparisons between years showed that during higher reported catch years, sardine larvae experienced lower temperatures and higher retention nearshore. Our results emphasize that sardine stock management efforts need to recognize the contribution of the temporally variable sardine environment to patterns in sardine recruitment and consequently in catches.The authors would like to thank Dr. Wilfredo Campos, Luke Felix, Dr. Rio Naguit, Denmark Recamara, and the Research for Sardines Volunteer Program (RSVP) volunteers for sharing sardine fisheries data; Arjay Cayetano for helping start the model used; and Iris Salud Bollozos for useful insights on larval ecology. This study was fully funded by the Department of Science and Technology–Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (DOSTPCAARRD) under the program, “Development of robust tools for managing sardine fisheries in the Philippines: Zamboanga Upwelling Bohol Sea System Program.” The authors declare no conflict of interest.
- 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.
- Structure and temporal dynamics of macroinfaunal communities of a sandy reef flat in the northwestern PhilippinesNacorda, Hildie Maria E.; Yap, Helen T. (Springer, 1997)Temporal variation in macroinfaunal community structure was assessed from monthly monitoring of the sandy substrate of the Lucero reef flat in Bolinao, Pangasinan (northwestern Philippines) between November 1990 and November 1991. The community was composed of 98 taxa from 10 phyla and was consistently dominated by the polychaete family Syllidae (19–33% of monthly total abundance). Five polychaete and crustacean taxa co-dominated with the syllids and exhibited monthly shifts in dominance ranks. Overall, there was no significant change in the composition of the community after a year. Results of the study show that the temporal dynamics of the community was a function of the seasonality in salinity and of the relatively consistent nature of the substrate. Abundances of macroinfaunal crustaceans, chaetognaths, and molluscs fluctuated significantly over 12 months, and corresponded to the seasonal fluctuation in salinity. Total and polychaete abundances did not show significant monthly variation, but tended to be influenced by salinity changes. Densities of turbellarians, nemerteans, and echinoderms appeared homogeneous across 12 months, and correlated with the consistency of substrate structure in the reef flat over the experimental period. In addition, sipunculid numbers seemed to be supported by the stable amount of organic matter in the sandy substrate.