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    Fungal pathogen associated with Rhizophora stylosa: A comparative study between oiled and unoiled sites within Taklong Island National Marine Reserve (TINMAR), Nueva Valencia, Guimaras
    Balanga-an, Kristoffer (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2009-03)
    Mangroves, refer to an assemblage of trees and shrubs that inhabit the coastal intertidal zone in tropical and subtropical regions. They help in the soil formation, protection, and stabilization of our coastal environment as well as serve as shelter and breeding grounds for some of our marine organisms. A mangrove habitat represents the borderline between land and sea and is considered as one of the principal places where spilled oil and associated impacts converge. Oil spill threaten mangroves by predisposing the plants to fungal attacks thereby reducing their resistance to stress and diseases. Studies also show that certain fungi species are able to utilize oil in contaminated mangrove species. This study generally aims to compare the fungal population found on the diseased leaves of Rhizophora stylosa between oiled and unoiled sites in the Taklong Island National Marine Reserve (TINMAR). It also aims to isolate, characterize and identify fungi present in diseased leaves of Rhizophora stylosa using potato dextrose agar (PDA) culture media and determine their frequency of occurrence. Leaf samples were collected from two sites in TINMAR, one of which was contaminated by oil and the other one was not. Three trees were selected to represent each of the two sampling sites (oiled and unoiled), and to each of the selected trees, three diseased leaves were collected. The results of this study showed the dominance of some species of fungi namely, Aspergillus (40%), Penicillium (20%), Cladosporium (13.33%), Monilia (6.67%), Mycelia (6.67%), Humicola (6.67%), and Pestalotiopsis (6.67%). Five out of these seven genera were isolated from the unoiled site while six of these were isolated from the oiled site. Generally, the fungal population was observed to be greater in the oiled site than in the unoiled. This preliminary data indicate that R. stylosa might still be undergoing stress due to the remaining components of the spilled oil in the area. However, this can only be resolved by further monitoring.
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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.