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03. Science and Technology (Natural Sciences) Committee

Permanent URI for this communityhttps://repository.unesco.gov.ph/handle/123456789/3

In creating a culture of peace and addressing sustainable development challenges, UNESCO aims to cultivate the generation and application of scientific knowledge among its Member States. At UNACOM, we facilitate access to UNESCO’s international programmes in the sciences, such as the Intergovernmental Oceanographic Commission (IOC), Man and the Biosphere (MAB) Programme, and International Geoscience and Geoparks Programme (IGGP), among others.

Through this sector, the Commission aims to contribute to the following SDGs: 11 - Sustainable Cities and Communities, 13 - Climate Action, 14 - Life Below Water, and 15 - Life On Land. With the overarching vision of the 2023-2028 Philippine Development Plan (PDP), UNACOM targets grassroots-inspired cultural heritage and biodiversity protection and conservation, as well as multi-stakeholder partnerships for SDGs promotion.

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Author: search.filters.author.Hinaloc, Lourie Ann R.Ocean Decade Challenge: search.filters.odc.Challenge 2: Protect and restore ecosystems and biodiversity

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    Nitrate and phosphate uptake of morphologically distinct calcified macroalgae
    Narvarte, Bienson Ceasar V.; Hinaloc, Lourie Ann R.; Gonzaga, Shienna Mae C.; Crisostomo, Bea A.; Genovia, Tom Gerald T.; Roleda, Michael Y. (Informa UK Limited, 2023-05-02)
    Calcified macroalgae are essential components of marine ecosystem, yet much of their physiology remains to be understood. Here, the nutrient (NO3– and PO4–3) uptake physiologies of two branched macroalgae, Actinotrichia fragilis (Nemaliophycidae) and Amphiroa fragilissima (Corallinophycidae), and the non-geniculate rhodolith Sporolithon sp. (Corallinophycidae) were examined. Sporolithon sp. had the lowest uptake rate through time and the three calcified macroalgae had a surge in NO3– and PO4–3 uptake that occurred between 3 and 20 min, with a maximum uptake at 3 min, after which the nutrient uptake rates declined. The NO3– uptake of the three calcified macroalgae followed Michaelis-Menten kinetics. For NO3– uptake, Sporolithon sp. had the lowest Km (2.72 ± 0.97 µM), Vmax (0.08 ± 0.01 µmol gDW–1 h–1), Vmax/Km (0.05 ± 0.03 µmol gDW–1 h–1 µM−1) and α (0.01 ± 0.00 µmol gDW–1 h–1 µM−1), while A. fragilis had the highest Km (12.35 ± 0.71 µM) and Vmax (6.41 ± 0.23 µmol gDW–1 h–1), and A. fragilissima had the highest Vmax/Km (1.52 ± 0.26 µmol gDW–1 h–1 µM−1) and α (0.37 ± 0.01 µmol gDW–1 h–1 µM−1). Moreover, the PO4–3 uptake rate of the three species was faster at higher PO4–3 levels. These differences in species-specific nutrient uptake traits are likely caused by differences in morphology. These traits are important for survival and proliferation of this group of marine organisms, particularly in a nutrient-variable environment.
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    Physiological and biochemical characterization of new wild strains of Kappaphycus alvarezii (Gigartinales, Rhodophyta) cultivated under land-based hatchery conditions
    Narvarte, 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.