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National Committee on Marine Sciences (NCMS)

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SDG: search.filters.sdg.SDG 13 - Climate actionUNESCO Keyword: search.filters.subject.Marine environment

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    Characteristics of marine heatwaves in the Philippines
    Edullantes, Brisneve; Concolis, Brenna Mei M.; Quilestino-Olario, Raven; Atup, Dale Patrick D.; Cortes, Aiza; Yñiguez, Aletta T. (Elsevier, 2023-09)
    Marine Heatwaves (MHWs) are prolonged, discrete, and anomalously warm events, which have recently gained global attention due to their far-reaching effects and reported impacts. Although intensive studies have been carried out at global and regional scales, these events remained understudied in the Philippines – a country with high marine biodiversity. The Philippines is highly vulnerable to the impacts of these extreme events as it lies in the western boundary of the Pacific that is considered as a hotspot for MHWs. The present study used multi-year climatic sea surface temperature (SST) record to detect MHWs in the Philippines. The detected events were then characterized using the standardized metrics. Linear trend analysis was conducted to determine the magnitude and direction of the change of the MHW metrics over time. Decadal trend revealed that MHWs in the Philippines significantly increased from seven MHWs in the 1980s to 37 MHWs in the last decade. Moreover, increased duration was remarkable in 2020 with 276 MHW days. MHW frequency and duration were increasing at a rate almost twice as its neighboring waters. Intensities did not significantly increase with time, but the highest SST anomaly is associated with El Niño Southern Oscillation. Furthermore, the eastern and western region of the Philippines is vulnerable to MHWs, but hotspots are mostly confined in the West Philippine Sea and western tropical Pacific. An in-depth investigation of the drivers of MHWs is recommended to understand the physical mechanisms of the development of these extreme thermal events in the Philippine seas. The findings have significant implications for coastal marine resource management, highlighting the need for adaptive management strategies and increased monitoring and research efforts to mitigate the impacts of MHWs on marine ecosystems and local economies in the Philippines.
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    Attachment of potential cultivable primo-colonizing bacteria and its implications on the fate of low-density polyethylene (LDPE) plastics in the marine environment
    Bitalac, Justine Marey S.; Lantican, Nacita B.; Gomez, Norchel Corcia F.; Onda, Deo Florence L. (Elsevier, 2023-06-05)
    Plastics released in the environment become suitable matrices for microbial attachment and colonization. Plastics-associated microbial communities interact with each other and are metabolically distinct from the surrounding environment. However, pioneer colonizing species and their interaction with the plastic during initial colonization are less described. Marine sediment bacteria from sites in Manila Bay were isolated via a double selective enrichment method using sterilized low-density polyethylene (LDPE) sheets as the sole carbon source. Ten isolates were identified to belong to the genera Halomonas, Bacillus, Alteromonas, Photobacterium, and Aliishimia based on 16S rRNA gene phylogeny, and majority of the taxa found exhibit a surface-associated lifestyle. Isolates were then tested for their ability to colonize polyethylene (PE) through co-incubation with LDPE sheets for 60 days. Growth of colonies in crevices, formation of cell-shaped pits, and increased roughness of the surface indicate physical deterioration. Fourier-transform infrared (FT-IR) spectroscopy revealed significant changes in the functional groups and bond indices on LDPE sheets separately co-incubated with the isolates, demonstrating that different species potentially target different substrates of the photo-oxidized polymer backbone. Understanding the activity of primo-colonizing bacteria on the plastic surface can provide insights on the possible mechanisms used to make plastic more bioavailable for other species, and their implications on the fate of plastics in the marine environment.