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Journal Articles - UP - MSI

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  • Community structure of periphytic diatoms in early-stage marine biofilms in a mariculture-impacted area
    Baure, Jerwin; San Diego-McGlone, Maria Lourdes; Juinio–Meñez, Marie Antonette (Science and Technology Information Institute, 2022-07-06)
    Periphytic diatoms constitute a major part of complex unicellular aggregations called marine biofilm or periphyton, of which little is known about in tropical marine environments. The early-stage community structure of periphytic diatom genera on two artificial substrates – glass slide and polycarbonate sheets was characterized. These artificial substrates were placed underwater for 6 d and examined on Days 1, 3, and 6 in four sites around Santiago Island, Bolinao, Pangasinan, Philippines, with different relative distances from the intensive milkfish mariculture area. Correlations of diatom community structures in these sites with physico-chemical factors were investigated. The five most abundant diatom genera – namely, Cylindrotheca, Nitzschia, Navicula, Amphora, and Pleurosigma – exhibited a weak correlation with nutrients. Less abundant genera Pseudonitzschia, Haslea, Bacillaria, Thalassionema, Rhizosolenia, Eucampia, Diploneis, Asterionellopsis, Chaetoceros, Bacteriastrum, Licmophora, Skeletonema, Lioloma, Thalassiosira, and Thalassiothrix showed a positive correlation with nutrients. Among sites, the highest benthic diatom cell densities (4.6 × 105 cells cm−2) after 6 d was found in Lucero. Generic richness and diversity varied among sites, with the highest diversity (H’ = 1.58) on Day 1 in Tomasa, the site nearest to the mariculture area, whereas the highest richness (D = 2.17–3.26) for all days and diversity (H’ = 1.38–1.52) for Days 3 and 6 were recorded in Silaqui, the most distal site. Generally, the highest diversity and richness were found on Day 1, which then decreased on succeeding days in all sites. The lack of a clear patternin community structure among sites relative to the proximity of these sites to the mariculture area may in part be attributed to the presence of other nutrient sources. Results of the study provide baseline information on the variability of periphytic diatom community structure in a mariculture-impacted area, and insights on how benthic diatoms may be used in monitoring the impacts of nutrient pollution.
    This work was supported by the Department of Science and Technology–Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development under Grant QMSR-MRRDMEC-295-1449. The authors would like to thank Tirso O. Catbagan and Garry R. Bucol for their assistance during field sampling, and Timothy James Cipriano for the site map. We would also like to thank the Marine Biogeochemistry Laboratory of the Marine Science Institute, University of the Philippines Diliman for providing environmental data.
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    Evolving governance structures in community-based sandfish mariculture and their interactions with livelihood outcomes: Evidence from the Philippines
    Fabinyi, Michael; Gorospe, Jay R; McClean, Nicholas; Juinio–Meñez, Marie Antonette (Frontiers Media SA, 2022-11-02)
    Sea cucumber mariculture is an important emerging field of practice and applied research in the coastal tropics. This is due to the existing importance of tropical sea cucumber fisheries for wealth generation and poverty reduction, and the potential for mariculture to contribute to the longer term sustainability of these fisheries while generating benefits additional to those from wild caught sea cucumber. Understanding the optimal institutional arrangements for sea cucumber mariculture is an important area of focus in this field, with a variety of arrangements currently in place. This paper documents the establishment of a communal form of sea ranching in the Philippines, as a case study of community level institutional processes. It describes the background to establishment of the sea ranch in the community of Victory, challenges encountered and how these were managed, and the evolution of governance arrangements. In charting this process, we assess the impacts on livelihood outcomes, highlighting this as a crucial aspect influencing this evolution and the nature of community involvement in the sea ranch. While the sea ranching project generated a range of benefits for livelihoods, including possible spillover effects for the surrounding fishery, substantial economic returns from harvests did not occur. Thus, the system of governing the sea ranch evolved from a communal model to a more exclusive household model primarily to improve operational efficiency. In order for possible benefits of the sea ranch to be sustained and enhanced, greater integration with fisheries management and government support will be needed.
    We are grateful to the Samahan ng Maliliit na Mangingisda ng Barangay Victory, Inc., the local government unit of Barangay Victory and Bolinao for their support to the Sea cucumber Research Program. We are also thankful to Tirso Catbagan, Josh Caasi, Rona Cabanayan-Soy, and Garry Bucol for their invaluable assistance during the field monitoring of sandfish in the sea ranch.
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    Ensuring aquatic food security in the Philippines
    Cabral, Reniel; Geronimo, Rollan; Mamauag, Antonio Samuel; Silva, Juan; Mancao, Roquelito; Atrigenio, Michael (National Fisheries Research and Development Institute, 2023-12)
    The human population of the Philippines is expected to reach 158 million by the year 2050, or an increase of 37% relative to 2022. This implies increased demand for aquatic food (or “fish” hereafter). This begs the question of whether the Philippines can meet the expected increase in fish demand. We estimate that even if the Philippines can maintain its current fish production, the Philippines will still require 1.67 million metric tons more fish per year by 2050 to at least maintain its current per capita fish consumption of 34.27 kg per year. Continued mismanagement of inland and marine fisheries will further widen the gap in fish supply. However, we argue that simultaneously rebuilding overfished fisheries, restoring degraded habitats crucial to supporting productive fisheries, addressing current threats to fisheries sustainability, and expanding sustainable marine aquaculture (or mariculture) have the potential to meet future fish demand in the Philippines. Sustainably expanding mariculture requires careful siting and management of mariculture development areas so that mariculture can improve food security without disenfranchising and marginalizing local coastal communities.
    This policy brief is the product of the address delivered by RBC during the 44th Annual Scientific Meeting of the National Academy of Science and Technology, Philippines, last July 2022, with the theme Foresight 2050: Science for a Sustainable Future. We dedicate this work in memory of our friend, Lito Mancao, who championed good governance in the Philippine fisheries and has generously supported numerous fisheries researchers and practitioners.