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National Committee on Marine Sciences (NCMS)

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    Fish predation on mangrove-associated penaeids: The role of structures and substrate
    Primavera, J. H. (Elsevier BV, 1997-08)
    The effect of habitat structure and substratum on predation of the greasyback shrimp Metapenaeus ensis (De Haan), white shrimp Penaeus merguiensis De Man and tiger shrimp Penaeus monodon Fabricius by sea bass Lates calcarifer Bloch and mangrove snapper Lutjanus argentimaculatus (Forsskal) was evaluated. The shrimp juveniles measured 6–15 mm in carapace length; fish measured 6.5–12.5 cm in standard length; structure types were pneumatophores of the mangrove Sonneratia griffithii Kurz and dried coconut leaf bracts; structure densities were 0, 32 and 98 pneumatophores per tank; and sediment particle sizes were pebbles, sand-granules and silt–sand. Predation on shrimp was significantly higher in controls or bare sand (48.7%) than among pneumatophores (29.9%), but not among leaf bracts (43.5%). Shrimp mortality was also significantly higher on bare sand (72.9%) compared to medium-density (54.2%), but not high-density (68.8%), pneumatophores. Fish predation on the burying shrimp M. ensis was affected by predator type but not by sediment size. The generally higher predation rates of snapper may be due to their habit of leaving unconsumed pieces of shrimp, whereas sea bass which devour whole prey require fewer shrimp to reach satiation. Moreover, the presence of structures did not affect sea bass behaviour of chasing prey among pneumatophores and under leaf bracts, but reduced predation by the relatively passive snapper. Predation rates among pneumatophores vs. control, and among medium-density pneumatophores vs. bare sand, were lower for P. monodon but not P. merguiensis. This may be related to the greater and more frequent use of (laboratory) shelters by juvenile tiger shrimp compared to white shrimp. The results demonstrate that the effective provision of shelter depends not only on structure type and density but on the behaviour of predator and prey as well. The use of mangrove structures (pneumatophores) by juvenile shrimp as refuge from predation is also documented for the first time.
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    Multi-scale coral reef and seascape habitat variables combine to influence reef fish assemblages
    Sievers, 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.
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    Variation in epibiont communities among restocked giant clam species (Cardiidae: Tridacninae) and across different habitat types
    de Guzman, Ian Joseph A.; Cabaitan, Patrick C.; Hoeksema, Bert W.; Sayco, Sherry Lyn G.; Conaco, Cecilia (Springer, 2023-07-07)
    Giant clam shells provide a solid substrate for various species of epibionts. Yet, it is not well known how epibiont communities vary among populations of different giant clam species and in giant clams restocked in different habitat types. Here, we examined differences in the epibiont communities of three species of giant clams with different shell morphology (Tridacna gigas, Tridacna derasa, and Hippopus hippopus), and characterized the epibiont communities on T. gigas from three different habitat types (sandy reef flat, seagrass bed, and coral reef). Tridacna gigas had higher species richness, abundance, and cover of epibionts compared to the other two species. Tridacna gigas in coral reef habitat also displayed higher species richness and cover of sessile epibionts, while the same species in the sandy reef flat had higher species richness and abundance of mobile epibionts. Epibiont communities were more variable across habitat types than among different giant clam species restocked in a similar area. Differences in abundance of Trochus sp., Pyramidella sp., and crustose coralline algae contributed to the variability in epibiont communities among the giant clam species and across habitats. A few taxa were observed only on specific giant clam species and sites. For instance, Diadema sp. and Echinometra sp. were found only on T. gigas, and Diadema sp. was present only in the sandy reef flat. Both the complexity of the giant clam shells and habitat type contribute to differences in associated epibiont communities. This further emphasizes the ecological importance of giant clams as habitats for other invertebrates.
    The authors acknowledge Jun Castrence and the staff of Bolinao Marine Laboratory for assistance with field work. We also acknowledge the assistance of Edwin Dumalagan with coral and algae identification, Timothy Quimpo for his assistance and advice on statistical analysis, and Elizabeth Gomez for her assistance in generating the map of study sites. Lastly, we would like to thank members of the Coral Reef Ecology Laboratory (CoRE) for their helpful comments and suggestions on the study. This study was supported by a grant from the Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development of the Department of Science and Technology to PCC and CC (QMSR-MRRD-MEC-314-1542) and a Department of Science and Technology ASTHRDP Scholarship and University of the Philippines Marine Science Institute Thesis Writing Grant 2020 to ID. We thank the reviewers for the suggestions that helped improve our paper.
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    World Migratory Bird Day 2021: Understanding the vanishing migratory birds
    Mayuga, Jonathan L. (Philippine Business Daily Mirror Publishing, Inc., 2021-10-31)
    Birds travel thousands of kilometers across oceans and continents to escape the cold winter and move to warmer areas in search of food for survival and to breed. In the Philippines, this natural phenomenon happens between the months of September to April when flocks of birds start arriving in September. They find a suitable place to feed and roost, and leave in March or April the following year to return to their place of origin when the temperature becomes tolerable.