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National Committee on Marine Sciences (NCMS)

Permanent URI for this communityhttps://repository.unesco.gov.ph/handle/123456789/6

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    A review of the status of Philippine reefs
    Gomez, E. D.; Aliño, P. M.; Yap, H. T.; Licuanan, W. Y. (Elsevier BV, 1994-01)
    Since 1979, the status of Philippine reefs has been periodically updated. While conditions of the reefs during the early surveys were assessed in terms of live coral cover per se, the ‘coral mortality index’ was applied to the sets of data collected during the past 7 yr which may be a better gauge in determining the health of the reefs. Generally, most reefs surveyed are in fair condition. Major destructive factors described are sedimentation and siltation from coastal development and activities inland, illegal and destructive methods of fishing, and overfishing. If the reefs are to continue to provide for the present and future users, the ecological processes that render them productive must be maintained through integrated approaches of coastal area management.
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    Using deep-belief networks to understand propensity for livelihood change in a rural coastal community to further conservation
    Labao, Alfonso B.; Naval, Prospero C. Jr; Yap, David Leonides T.; Yap, Helen T. (Wiley Blackwell, Inc., 2020-08)
    Overharvesting of terrestrial and marine resources may be alleviated by encouraging an alternative configuration of livelihoods, particularly in rural communities in developing countries. Typical occupations in such areas include fishing and farming, and rural households often switch livelihood activities to suit climate and economic conditions. We used a machine-learning tool, deep-belief networks (DBN), and data from surveys of a rural Philippine coastal community to examine household desire to change livelihood. This desire is affected by a variety of factors, such as income, family needs, and feelings of work satisfaction, that are interrelated in complex ways. In farming households, livelihood changes often occur to diversify resources, increase income, and lessen economic risk. The DBN, given its multilayer perceptron structure, has a capacity to model nonlinear relationships among factors while providing an acceptable degree of accuracy. Relative to a set of 34 features (e.g., education, boat ownership, and work satisfaction), we examined the binary response variables desire to change work or not to change work. The best network had a test set accuracy of 97.5%. Among the features, 7 significantly affected desire to shift work: ethnicity, work satisfaction, number of persons in a household in ill health, number of fighting cocks owned, fishing engagement, buy-and-sell revenue, and educational level. A cross-correlation matrix of these 7 features indicated households less inclined to change work were those engaged in fishing and retail buying and selling. For fishing, provision of economic and other incentives should be considered to encourage changing from this occupation to allow recovery of fishery resources.
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    Intact shallow and mesophotic assemblages of large carnivorous reef fishes underscore the importance of large and remote protected areas in the Coral Triangle
    Salvador, Mikaela L.; Utzurrum, Jean Asuncion T.; Murray, Ryan; Delijero, Kymry; Conales, Segundo F.; Bird, Christopher E.; Gauthier, David T.; Abesamis, Rene A. (Wiley, 2024-02-23)
    1. Overfishing remains a threat to coral reef fishes worldwide, with large carnivores often disproportionately vulnerable. Marine protected areas (MPAs) can restore fish populations and biodiversity, but their effect has been understudied in mesophotic coral ecosystems (MCEs), particularly in the Coral Triangle. 2. Videos were analysed from baited remote underwater video systems deployed in 2016 to investigate the assemblage structure of large carnivorous fishes at shallow (4–12 m) and mesophotic (45–96 m) depths in two of the largest and most isolated MPAs in the Philippines: an uninhabited, fully no-take MPA enacted in 1988 (Tubbataha Reefs Natural Park) and an archipelagic municipality surrounded by an extensive but not fully no-take MPA declared in 2016 (Cagayancillo). Taxa focused on were groupers (Serranidae), snappers (Lutjanidae), emperors (Lethrinidae), jacks (Carangidae) and the endangered Cheilinus undulatus (Labridae). 3. Mean abundance and species richness were not greater in TRNP than in Cagayancillo regardless of depth despite long-term protection in the former. Limited impacts of fishing in Cagayancillo may explain this result. Differentiation of fish assemblages was evident between TRNP and Cagayancillo but more obvious between depths at each location, probably due more to habitat than MPA effects. In Cagayancillo, overall carnivorous reef fish, grouper and jack mean abundance were 2, 2 and 10 times higher, respectively, at mesophotic depths, suggesting that MCEs can serve as deep refugia from fishing. 4. These findings of differentiation between depths and higher abundance of certain taxa in mesophotic depths emphasize that MCEs are distinct from shallow reefs, serve as important habitat for species susceptible to overfishing and, thus, must be explicitly included in the design of MPAs. This study also highlights the value of maintaining strict protection of MPAs like TRNP for the Coral Triangle and an opportunity to safeguard intact fish assemblages in Cagayancillo by expanding its no-take zones.