National Committee on Marine Sciences (NCMS)
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- Fisheries Administrative Order No. 1. Organization and functions of the Bureau of Fisheries.(Department of Agriculture and Natural Resources, 1947-07-01)
- Sea surface carbonate dynamics at reefs of Bolinao, Philippines: Seasonal variation and fish mariculture-induced forcingIsah, Raffi R.; Enochs, Ian C.; San Diego-McGlone, Maria Lourdes (Frontiers, 2022-11-11)Coral reefs are vulnerable to global ocean acidification (OA) and local human activities will continue to exacerbate coastal OA. In Bolinao, Philippines, intense unregulated fish mariculture has resulted in regional eutrophication. In order to examine the coastal acidification associated with this activity and the impact on nearby coral reefs, water quality and carbonate chemistry parameters were measured at three reef sites, a mariculture site and an offshore, minimally impacted control site during both the wet and dry season. Additionally, benthic community composition was characterized at reef sites, and both autonomous carbonate chemistry sampling and high-frequency pH measurements were used to characterize fine-scale (diel) temporal variability. Water quality was found to be poorer at all reefs during the wet season, when there was stronger outflow of waters from the mariculture area. Carbonate chemistry parameters differed significantly across the reef flat and between seasons, with more acidic conditions occurring during the dry season and increased primary production suppressing further acidification during the wet season. Significant relationships of both total alkalinity (TA) and dissolved inorganic carbon (DIC) with salinity across all stations may imply outflow of acidified water originating from the mariculture area where pH values as low as 7.78 were measured. This apparent mariculture-induced coastal acidification was likely due to organic matter respiration as sustained mariculture will continue to deliver organic matter. While TA-DIC vector diagrams indicate greater contribution of net primary production, net calcification potential in the nearest reef to mariculture area may already be diminished. The two farther reefs, characterized by higher coral cover, indicates healthier ecosystem functioning. Here we show that unregulated fish mariculture activities can lead to localized acidification and impact reef health. As these conditions at times approximate those projected to occur globally due to OA, our results may provide insight into reef persistence potential worldwide. These results also underscore the importance of coastal acidification and indicate that actions taken to mitigate OA on coral reefs should address not only global CO2 emissions but also local perturbations, in this case fish mariculture-induced eutrophication.
- 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.
- Ensuring aquatic food security in the PhilippinesCabral, Reniel; Geronimo, Rollan; Mamauag, Antonio Samuel; Silva, Juan; Mancao, Roquelito; Atrigenio, Michael (National Fisheries Research and Development Institute, 2023-12)The human population of the Philippines is expected to reach 158 million by the year 2050, or an increase of 37% relative to 2022. This implies increased demand for aquatic food (or “fish” hereafter). This begs the question of whether the Philippines can meet the expected increase in fish demand. We estimate that even if the Philippines can maintain its current fish production, the Philippines will still require 1.67 million metric tons more fish per year by 2050 to at least maintain its current per capita fish consumption of 34.27 kg per year. Continued mismanagement of inland and marine fisheries will further widen the gap in fish supply. However, we argue that simultaneously rebuilding overfished fisheries, restoring degraded habitats crucial to supporting productive fisheries, addressing current threats to fisheries sustainability, and expanding sustainable marine aquaculture (or mariculture) have the potential to meet future fish demand in the Philippines. Sustainably expanding mariculture requires careful siting and management of mariculture development areas so that mariculture can improve food security without disenfranchising and marginalizing local coastal communities.
- Seaweed as a resilient food solution after a nuclear warJehn, Florian Ulrich; Dingal, Farrah Jasmine; Mill, Aron; Harrison, Cheryl; Ilin, Ekaterina; Roleda, Michael Y.; James, Scott C.; Denkenberger, David (American Geophysical Union, 2024-01-09)Abrupt sunlight reduction scenarios such as a nuclear winter caused by the burning of cities in a nuclear war, an asteroid/comet impact or an eruption of a large volcano inject large amounts of particles in the atmosphere, which limit sunlight. This could decimate agriculture as it is practiced today. We therefore need resilient food sources for such an event. One promising candidate is seaweed, as it can grow quickly in a wide range of environmental conditions. To explore the feasibility of seaweed after nuclear war, we simulate the growth of seaweed on a global scale using an empirical model based on Gracilaria tikvahiae forced by nuclear winter climate simulations. We assess how quickly global seaweed production could be scaled to provide a significant fraction of global food demand. We find seaweed can be grown in tropical oceans, even after nuclear war. The simulated growth is high enough to allow a scale up to an equivalent of 45% of the global human food demand (spread among food, animal feed, and biofuels) in around 9–14 months, while only using a small fraction of the global ocean area. The main limiting factor being the speed at which new seaweed farms can be built. The results also show that the growth of seaweed increases with the severity of the nuclear war, as more nutrients become available due to increased vertical mixing. This means that seaweed has the potential to be a viable resilient food source for abrupt sunlight reduction scenarios.
- Physiological and biochemical characterization of new wild strains of Kappaphycus alvarezii (Gigartinales, Rhodophyta) cultivated under land-based hatchery conditionsNarvarte, Bienson Ceasar V.; Hinaloc, Lourie Ann R.; Genovia, Tom Gerald T.; Gonzaga, Shienna Mae C.; Tabonda-Nabor, April Mae; Roleda, Michael Y. (Elsevier, 2022-12)The red alga Kappaphycus alvarezii is globally cultivated as a major source of k-carrageenan. Farming of this species through clonal propagation has been confined to a few good-quality commercial strains. After more than 50 years of successful cultivation and high productivity, the production of K. alvarezii in most “cottonii”-producing countries like the Philippines had declined in recent decades. This can be attributed to low genetic variability, making “old” cultivars more susceptible to environmental stressors, pests (epi- and endophytes) and diseases (e.g., ice-ice). Hence, the establishment of new cultivars from wild strains with desirable traits may provide alternative seedstocks with different genetic makeup from the currently farmed cultivars. Here, we examined the physiological and biochemical properties of 10 new wild strains of K. alvarezii, belonging to four non-commercially cultivated haplotypes, collected from Eastern Samar, Philippines. These strains were cultivated in an outdoor, land-based hatchery with ambient light and flow-through, nutrient replete seawater. Growth rates, ranging from 0.44 % to 3.74 % d-1, significantly varied among the strains but did not significantly vary among haplotypes. The cultivars also showed a notable change in color and morphology as they adapted to hatchery conditions. Pigments and total phenolic content did not significantly vary among cultivars. Proximate analysis showed that the dry biomass of all K. alvarezii strains was composed mainly of ash (ranging from 39.2 % to 51.0 %), followed by carbohydrate (ranging from 26.0 % to 35.3 %), and with trace amounts of proteins (ranging from 1.02 % to 4.61 %). Moreover, tissue stoichiometry (C, N and P) was comparable among the 10 strains. Considering the promising growth performance of strain SamW-014 under hatchery condition, we recommend its cultivation at sea and conduct corresponding carrageenan yield and quality analyses on its raw dried biomass. Among the 10 strains, five others are also of interest and for consideration. Thereafter, selected strain(s) will be introduced to seaweed farmers for future cultivation to increase biomass production, harvest yields, and income.