National Committee on Marine Sciences (NCMS)
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- Potential of sediment bacterial communities from Manila Bay (Philippines) to degrade low-density polyethylene (LDPE)Gomez, Norchel Corcia F.; Onda, Deo Florence L. (Springer, 2022-12-24)The persistence of plastics and its effects in different environments where they accumulate, particularly in coastal areas, is of serious concern. These plastics exhibit signs of degradation, possibly mediated by microorganisms. In this study, we investigated the potential of sediment microbial communities from Manila Bay, Philippines, which has a severe plastics problem, to degrade low-density polyethylene (LDPE). Plastics in selected sites were quantified and sediment samples from sites with the lowest and highest plastic accumulation were collected. These sediments were then introduced and incubated with LDPE in vitro for a period of 91 days. Fourier transform infrared spectroscopy detected the appearance of carbonyl and vinyl products on the plastic surface, indicating structural surface modifications attributed to polymer degradation. Communities attached to the plastics were profiled using high-throughput sequencing of the V4-V5 region of the 16S rRNA gene. Members of the phylum Proteobacteria dominated the plastic surface throughout the experiment. Several bacterial taxa associated with hydrocarbon degradation were also enriched, with some taxa positively correlating with the biodegradation indices, suggesting potential active roles in the partial biodegradation of plastics. Other taxa were also present, which might be consuming by-products or providing nourishment for other groups, indicating synergy in utilizing the plastic as the main carbon source and creation of a microenvironment within the plastics biofilm. This study showed that sediment microbes from Manila Bay may have naturally occurring microbial groups potentially capable of partially degrading plastics, supporting previous studies that the biodegradation potential for plastics is ubiquitously present in marine microbial assemblages.
- Fisheries Administrative Order No. 1. Organization and functions of the Bureau of Fisheries.(Department of Agriculture and Natural Resources, 1947-07-01)
- Attachment of potential cultivable primo-colonizing bacteria and its implications on the fate of low-density polyethylene (LDPE) plastics in the marine environmentBitalac, 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.
- Total polyphenol content of tropical marine and coastal flora: Potentials for food and nutraceutical applicationsNarvarte, Bienson Ceasar V.; Genovia, Tom Gerald T.; Hinaloc, Lourie Ann R.; Gonzaga, Shienna Mae C.; Tabonda-Nabor, April Mae; Palecpec, Flora Maye R.; Dayao, Helen M.; Roleda, Michael Y. (Springer, 2023-07-08)The marine environment is abundant in natural products that are beneficial to humans. Among these compounds are the polyphenols produced by marine flora as secondary metabolites and used as a defense against stressful environmental conditions. Accordingly, recent pharmacological and biomedical studies showed that polyphenols from marine and coastal floras have several important bioactivities including antioxidant property. In this study, we measured the total polyphenol content (TPC) of 75 species of marine-associated flora. The TPC of their methanolic extracts was measured spectrophotometrically using the Folin-Ciocalteu assay and was expressed both as mg phloroglucinol equivalent per g of dry weight (mg PGE g−1 DW) and as mg gallic acid equivalent per g dry weight (mg GAE g−1 DW). The TPC values are higher when expressed in terms of GAE compared to PGE. Also, the mean TPC of tracheopytes (229 ± 43.0 mg PGE g−1 DW) was higher compared to the mean TPC of macroalgae (69.4 ± 9.59 mg PGE g−1 DW). For macroalgae, ochrophytes (97.9 ± 22.7 mg PGE g−1 DW) had the highest mean TPC followed by chlorophytes (80.0 ± 20.5 mg PGE g−1 DW) and rhodophytes (49.5 ± 8.60 mg PGE g−1 DW). Moreover, our study also showed that TPC varied between young and mature tissues, among different color morphotypes and different parts of the plants. Although the concentrations of total polyphenols varied among species, ages, strains and parts of the plant, our study showed that marine and coastal floras are rich sources of polyphenols that could be further examined for their biological activities and other applications in food industry.
- Moving towards open data, public access, and information sharing to combat marine plastics pollution in the Philippines and the Southeast Asian regionAlindayu, Ricardo C.; Licnachan, Lance Oliver C.; Luzadas, Ramgem L.; Ignacio, Paul Samuel P.; Onda, Deo Florence L. (Elsevier, 2023-09-01)Despite the consistent tagging of countries in Southeast Asia as among the top polluters of plastics in the oceans and the increasing local literature documenting the presence and abundance of plastics in marine environments, there still lacks a comprehensive, open, and accessible repository for marine plastics pollution data in the region. As such, this study presents the development of the PlastiCount Pilipinas portal in line with the call for a common data repository by the Philippines’ National Plan of Action for the Prevention, Reduction, and Management of Marine Litter and the ASEAN Regional Action Plan for Combating Marine Debris in the ASEAN Member States. A total of 14 existing databases were reviewed to identify key features for the online portal implemented to promote ease of access and diversified functionality. For the database, a total of 38 publications, 2 reports, 1 scientific poster, and 3 baselining studies were used to develop the initial ground-truthed baseline for marine plastic pollution, covering 23 provinces and 14 regions across the Philippines. The challenges presented by an observed variation across different methodologies and reporting styles emphasize the critical need to harmonize methods toward generating a more refined national baseline for marine litter. The initial baseline data and other resources such as manuals, information sheets, photographs, news, and publications are uploaded onto a public online portal for viewing and download (https://plasticount.ph/). Data and resource submissions from the public are also accepted and considered for inclusion in the database. The insights gained from developing the online portal and database for the Philippines can be used to inform the development of a regional database for Southeast Asia towards reducing marine litter.
- Transcriptome-derived SNP markers for population assignment of sandfish, Holothuria (Metriatyla) scabraOrdoñez, June F.; Ravago-Gotanco, Rachel (Elsevier, 2024-01-30)The sandfish, Holothuria scabra is a commercially important fishery and aquaculture species contributing to the high-value sea cucumber industry. Overexploited across many areas throughout its distributional range, natural populations are considered in decline. Accurate genetic assignment to population of origin is becoming increasingly important for genetics-based marine fisheries management and monitoring, especially for species experiencing depletion of natural stocks and decline in fisheries productivity due to overfishing and illegal, unreported, and unregulated (IUU) fishing. Initiatives for genetics-based applications on economically important seafood such as H. scabra have been limited by the lack of comprehensive genome or transcriptome resources. The present study developed and evaluated the use of gene-associated single nucleotide polymorphism (SNP) markers to assign sandfish to three locations in the Philippines, in the proximity of existing and emerging hatchery production centers. In silico SNP discovery pipeline using pooled RNA-Seq libraries and medium-throughput genotyping approach generated a dataset comprising 115 individuals genotyped at 88 SNPs. Population assignment using machine-learning analysis and Bayesian approach revealed that the 88 transcriptome-derived SNPs allowed the assignment of sandfish individuals to population of origin, with an overall assignment accuracy of >80%. The novel SNPs developed could find their utility in facilitating the development of geographic traceability tools applicable in the context of sandfish aquaculture, fisheries management and conservation.
- Metamorphic success and production cost of Holothuria scabra reared on microalgae concentrates compared with live microalgaeGarpa, Tomilyn Jan; Caasi, Olivier Josh C.; Juinio–Meñez, Marie Antonette (Bureau of Fisheries and Aquatic Resources, 2024-03-07)The production of live microalgae poses challenges for the expansion of sandfish hatcheries, hindered by high costs and limited technical resources. In relation to this, the use of three imported commercial concentrates (Instant Algae®) - TW1200 (Thalassiosira weisflogii), TISO1800 (Isochrysis sp.), and Shellfish1800 (mixed diatom) - were compared with live Chaetoceros calcitrans (CC). The diet efficacy was evaluated based on larval development, growth, and survival to late auricularia (LA) with hyaline spheres (HS), and the number of post-settled juveniles. Larvae reared with TW did not progress beyond LA, while those fed CC exhibited earlier LA development, larger sizes (1028.43 ± 19.38 µm), and significantly more post–settled juveniles (9,268 ± 2,183.79) compared to SHELL and TISO. Although TISO larvae reached a larger size during LA (855.7 ± 62.67 µm), SHELL resulted in a higher number of post-settled juveniles. The better performance of CC and SHELL may be attributed to their higher carbohydrate content. Despite SHELL and TISO having lower juvenile yields and longer feeding durations, the estimated cost per juvenile using SHELL, TISO, and CC were PHP 2.00, PHP 11.77, and PHP 0.52, respectively. Results showed that microalgae concentrates are not a cost-effective option under the studied conditions. The potential use of microalgae concentrates as supplemental feeds and further research to develop the use of local microalgae concentrates to sandfish larval culture are discussed.