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Undergraduate Special Problem

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/30

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AGROVOC Keyword: search.filters.agrovoc.oil spillsCommittee Chair: search.filters.chair.Katalbas, Ma. Severa Fe

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    Preliminary assessment of forest canopy and seedling condions of mangroves in oil affected areas in Taklong Island National Marine Reserve, Guimaras
    Benitez, Zaina Lei Licaniel (2007-04)
    Mangroves are important ecologically and economically in coastal areas in tropica] and sub-tropical areas in the world. However, they continue to be under threat from various human activities either directly or indirectly. The recent oil spill off the coast of southern Guimaras has brought numerous damages to these critical habitats including the mangroves in Taklong Island National Marine Reserve. This study is part of the over all Oil Spill Assessment program conducted by University of the Philippines in the Visayas following the sinking of M.T. Solar 1. This study aimed to determine the effect of oil spill on shoot development as an indicator of health conditions of trees and seedlings of selected mangroves such as Aegiceras floridum, Avicenia marina, Rhizophora apiculata Rhizophora , Rhizophora stylosa, and Sonneratia alba, in Taklong Island National Marine Reserve. Specifically, it aims to determine 1) standing leaves, 2) new leaves, 3) leaf scars of trees and seedlings. Results showed that shoot development among trees were not significantly different between oiled and unoiled sites but closer examination of species response revealed significant differences on standing leaves and new leaves only. Seedling shoot development showed a consistent significant difference among species and between sites. Aegiceras floridum and Sonneratia alba were least affected as shown by the higher number of standing leaves and least number of leaf scar while the Rhizophora spp. and Avicennia marina had the greatest number of leaf scars and least number of standing leaves. Results of this study showed that seedlings are clearly under stress and are more sensitive to oiling than trees although species response also varied individually. While tree species such as the Rhizophora spp. (e.g. R. apiculata, R. stylosa and R. mucronata) appear to be the most sensitive compared with Aegiceras floridum, Avicennia marina and Sonneratia alba. Results of this study will be useful in providing new knowledge on the evaluation of impacts of oil spills on mangroves.
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    Fungal pathogens associated with Sonneratia alba: A comparative study between oiled and unoiled sites within Taklong Island National Marine Reserve (TINMAR), Nueva Valencia, Guimaras
    Albacete, May Therese F. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2009-03)
    Majority of researches on impacts of oil spills on mangroves focused on the immediate post-spill acute effects. However, the persistence of oil in sediments at oil spill sites has been reported in a number of published works. As such, this remaining oil could serve as source of stress to mangroves resulting into the expression of sub-lethal effects such as changes in foliage and canopy, abnormalities in reproductive structures among others. Furthermore, oil in mangroves also has the potential of increasing fungal attacks due to their impairment of natural defense mechanisms such as salt removal from leaves and trunks. Thus, this study was conducted to determine if there was a difference in fungal species composition and frequency of occurrence of fungal population of mangrove leaves collected in oiled and unoiled areas within Taklong Island National Marine Reserve, Nueva Valencia, Guimaras following the spill that occurred in August I1,2006. Fungi from diseased leaves of Sonneratia alba were isolated and characterized using Acidified Potato Dextrose Agar (APDA) for samples collected in January 2009 only. A total of 7 and 6 species were identified from among the isolates in oiled and unoiled sites. Although there is a little difference in species composition, almost all the isolated species was frequently occurring in both oiled and uncoiled sites. Gliomastix morurom (5.8%) in the unoiled site was only frequently occurring. The results may imply that difference in frequency of occurrence of certain species might be an indicator for sub-lethal effects of oil but needs further investigations to consider environmental factors among other factors.