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.
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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- Natural diet, feeding periodicity and functional response to food density of the abalone,Haliotis asininaL., (Gastropoda)Tahil, A. S.; Juinio‐Menez, M. A. (Hindawi Limited, 1999-02)The natural food spectrums of the different size groups of abalone, Haliotis asinina L., from Tawi-Tawi, southern Philippines, were determined by analysis of gut contents. Laboratory experiments were conducted to determine the feeding and defecation patterns and functional response of the abalone to varying food density under ambient water conditions. Like other tropical haliotids, H. asinina prefers red algae to brown algal species. Eighteen algal species, 72.2% of which are red algae (Rhodophyta), were observed in the gut contents of all size groups of abalone; Laurencia, Hypnea, Amphiroa and Coelothrix are the most frequent food species. Hypnea and Laurencia are also the most abundant food items of H. asinina. A chi-square test indicated that frequency of occurrence (%) of most algal food species in the gut samples is independent of the size of the animal. About 84% of all algal species were observed in the gut contents of small abalone. Haliotis asinina (mean shell length ± SD = 3.48 ± 0.05 cm) showed a distinct nocturnal feeding periodicity and remained cryptic during daylight hours. Feeding activity was intense from 1800 to 0200 h, but it slowed down a few hours before sunrise, resulting in about 11 h of feeding time within a 24-h cycle. Defecation occurred during the feeding period in proportion to the amount of food consumed and faecal production during the night was significantly higher than during the daylight hours. The total daily faecal output was 1.26 mg dry weight abalone–1. The experiments showed that H. asinina (mean shell length ± SD = 3.55 ± 0.02 cm) consumed more food when food density increased in linear proportion to food abundance. However, food consumption levelled off at a food density equivalent to 35% of body weight.
- Thecal tabulation, body scale morphology and phylogeny of Heterocapsa philippinensis sp. nov. (Peridiniales, Dinophyceae) from the PhilippinesBenico, Garry; Lum, Wai Mun; Takahashi, Kazuya; Yñiguez, Aletta T.; Iwataki, Mitsunori (Elsevier, 2021-08)The thecal tabulation and body scale structure of the marine armoured dinoflagellate Heterocapsa, isolated from Philippines, were examined using LM, SEM and TEM, and its phylogenetic position was inferred from ITS and LSU rDNA sequences. Cells were ovoid and the plate tabulation (Po, cp, X, 5′, 3a, 7′′, 6c, 5s, 5′′′, 2′′′′) was consistent with most Heterocapsa species. The second anterior intercalary plate (2a) had a circular pattern with a thick marginal border free of pores. The nucleus was longitudinally elongated and curved, and located at the dorsal side of the cell. Discoid lobes of brownish chloroplast were peripherally distributed, and a pyrenoid was positioned at the centre. The triradiate body scales, measuring 250–300 nm in diameter, consisted of a roundish basal plate with six radiating ridges, nine peripheral uprights/spines, and three radiating spines. These components were identical to those of H. pseudotriquetra and H. steinii, except for the roundish outline of basal plate. Molecular phylogeny showed that the species clustered with H. pseudotriquetra and H. steinii. This species was differentiated from all other Heterocapsa species in the sausage-shaped nucleus and circular pattern on the 2a plate. This study proposed a novel species Heterocapsa philippinensis sp. nov. for the isolate.
- Manzaea minuta gen. & comb. nov. (Scytosiphonaceae, Phaeophyceae) from the tropical Northwestern Pacific OceanSantiañez, Wilfred John E.; Kogame, Kazuhiro (Philippine Journal of Systematic Biology, 2022-07-11)Recent molecular-assisted taxonomic studies on the brown algal genus Hydroclathrus has resulted in discoveries of new taxa in the family Scytosiphonaceae, both at the genus and species level. However, phylogenetic studies on Hydroclathrus based on wide geographical sampling also suggested that the genus is not monophyletic. That is, one of the recently described species Hydroclathrus minutus is consistently segregated from the Hydroclathrus main clade. We propose here to segregate H. minutus from the brown algal genus Hydroclathrus and establish the new monotypic genus Manzaea (i.e., Manzaea minuta gen. & comb. nov.) based on information on molecular phylogenetics and morpho-anatomy. Morphologically, M. minuta is similar to Hydroclathrus and Tronoella in having clathrate (net-like) and spreading thalli but is differentiated from the latter two genera in having membranous thalli that are sometimes interadhesive resulting in portions of the thallus forming amorphous clumps. Additionally, Manzaea is distinguished from both clathrate genera in having thick-walled medullary cells and short closely arranged quadriseriate plurangia. Phylogenetic analyses (Maximum Likelihood and Bayesian Inference) based on single (plastidial psaA and rbcL genes) and concatenated (cox3 + psaA + rbcL) genes showed that M. minuta is consistently segregated from the highly supported clade of Hydroclathrus species and often clustering with Tronoella and/or Rosenvingea. Our proposal further increases the diversity of monotypic genera in the Scytosiphonaceae and underscores the need to conduct further studies on tropical seaweed biodiversity.WJES thanks Dr. Gavino C. Trono, Jr. and Dr. Edna T. Ganzon-Fortes for the inspiration and encouragement to conduct seaweed biodiversity and systematics research. WJES is funded by the University of the Philippines through the Balik PhD Program of the Office of the Vice President for Academic Affairs (OVPAA-BPhD-2018-05), the University of the Philippines Diliman through the In-house research grant of the Marine Science Institute, and the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of the Government of Japan under the Monbukagakusho Scholarship Grant. WJES also acknowledges the support of the Department of Science and Technology (DOST)-Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD) of the Government of the Philippines through the DOST Balik Scientist Program.
- Sargassum sp. juice as an early juvenile supplemental feed for Stichopus cf. horrensIbañez, Glaiza; Cabanayan-Soy, Rona; Baure, Jerwin; Juinio-Meñez, Marie Antonette (Springer, 2022-09-28)The development of an efficient and low-cost feed is important to reduce the production and maintenance costs of microalgae. In this study, two experiments were conducted to evaluate the feasibility of using Sargassum sp. juice (SARG) to boost the growth and survival of post-settled Stichopus cf. horrens juveniles. Experiment 1 tested whether SARG improves growth compared with live microalgae diets, Chaetoceros calcitrans (Cc), combined Cc and Navicula ramosissima (Nr), and an unfed treatment. Experiment 2 determined the best SARG concentration—high feeding regime (HFR; 1 mL ind−1), medium (MFR; 0.5 mL ind−1), or low (LFR; 0.25 ml ind−1), relative to live microalgae Chaetoceros muelleri (CM). Juveniles in both experiments were reared for 30 days. In Experiment 1, the average daily growth rate (DGRL) of juveniles in SARG (0.04 ± 0.01 cm d−1) was the highest although not significantly different from Cc and Cc + Nr, but was significantly higher than the control. In Experiment 2, DGRL at day 14 in HFR (− 0.02 ± 0.02 cm d−1) was significantly lower than LFR (0.01 ± 0.01 cm d−1) and MFR (0.02 ± 0.02 cm d−1). Survival was higher in all SARG treatments compared with CM, while a significant decrease in feeding activity was observed in HFR by day 30. Results indicate that concentrations of 0.25–0.5 mL SARG per juvenile can boost growth and be an alternate diet for post-settled juveniles during early rearing. However, SARG alone is not sufficient to maintain growth beyond 3 weeks. With SARG feed supplementation and water quality management, the scaling-up of juvenile production of this emergent culture species can be accelerated.Our sincere gratitude to Mr. Tirso Catbagan and Mr. Garry Bucol for their assistance in the set-up of the experiments. We also thank Ms. Rose Angeli Rioja and Ms. JayR Gorospe for providing inputs to improve this paper. We also thank the Sea cucumber Research Team and the staff of the University of the Philippines—Marine Science Institute, Bolinao Marine Laboratory for their support and assistance during the conduct of the study.
- Molecular-assisted taxonomic study on the Sargassum C.Agardh (Fucales, Phaeophyceae) in Northwestern Luzon, PhilippinesSantiañez, Wilfred John E.; Lastimoso, John Michael L.; Hoshino, Masakazu; Villafuerte, Brix Nester Q.; Kogame, Kazuhiro; Trono, Gavino C. (Museum National d'Histoire Naturelle, 2023-10-18)The diversity of the brown algal genus Sargassum C.Agardh in the Philippines is the highest in the tropical western Pacific Ocean. However, most studies on Philippine Sargassum are based on morphoanatomies and the assumption that the genus is very diverse in the country has never been tested based on molecular information. Considering that many Sargassum species are highly polymorphic and the recent advance on Sargassum systematics facilitated by molecular phylogenetic studies, we believe that the species of Sargassum from the Philippines should now be reassessed with the tools of molecular taxonomy. We present here the results of our molecular-assisted taxonomic studies on the Sargassum of the northern Philippines, particularly along the coasts of four coastal provinces in northwestern Luzon (i.e., Ilocos Norte, Ilocos Sur, La Union, and Pangasinan). We recognized three distinct species lineages, namely, Sargassum aquifolium (Turner) C.Agardh, Sargassum ilicifolium (Turner) C.Agardh, and Sargassum polycystum C.Agardh based on our molecular analyses of 74 specimens from our study areas. Our morphological observations on the range of characters of these species also suggest that several common Sargassum taxa in the Philippines have been misidentified. Particularly, specimens previously attributed to S. kushimotense Yendo should be referred as S. aquifolium while the widely distributed and highly plastic S. ilicifolium is often confused and identified in the Philippines under several names including S. crassifolium J.Agardh, S. cristaefolium C.Agardh, and S. turbinarioides Grunow. Taken together, our results suggest that Sargassum biodiversity in the Philippines may have been inflated by misidentifications, and, that species diversity is actually much lower than initially thought.
- Taxonomy and toxin production of Gambierdiscus carpenteri (Dinophyceae) in a tropical marine ecosystem: The first record from the PhilippinesVacarizas, Joshua; Benico, Garry; Austero, Nero; Azanza, Rhodora (Elsevier, 2018-12)Morphological and phylogenetic analysis showed that the Gambierdiscus isolate from Bolinao, Philippines belongs to the species of G. carpenteri. It was morphologically more similar to the Merimbula strain than the subtropical Florida Keys strain. Growth and toxin production were also investigated at varying levels of temperature, salinity, and irradiance. Gambierdiscus are known to grow favorably in a low light environment. However, this study showed high growth rates of G. carpenteri even at high irradiance levels. Generally, cells produced more toxins at lower treatment levels. Highest cellular toxin content recorded was 7.48 ± 0.49 pg Pbtx eq/cell at culture conditions of 25 °C, 100 μmol photons m−2 s−1, and salinity of 26. Growth rate and toxin production data suggest that cells produced more toxins during the slowest growth at certain range of treatments. This information gives insight into how changes in environmental conditions may affect toxin production and growth of G. carpenteri.
- Nitrate and phosphate uptake of morphologically distinct calcified macroalgaeNarvarte, 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.This is contribution no. 494 from the University of the Philippines – the Marine Science Institute, (UP-MSI). We thank our laboratory aides Jerry Arboleda, Guillermo Valenzuela and Robert Valenzuela for their help in our sample collection. We also thank the UPMSI-Bolinao Marine Laboratory for providing us with the venue where we conducted our experiment and laboratory analyses. MYR acknowledges the Department of Science and Technology (DOST) Balik Scientist Program (BSP) fellowship.
- W. Visayas coastal waters still red-tide freeZabal, Boy Ryan (Panay News, Inc., 2019-12-05)The Bureau of Fisheries and Aquatic Resources (BFAR) said coastal waters of Panay and Negros Islands’ remain safe from toxic red tide. In its Dec. 2 bulletin, BFAR issued no red tide advisory in the coastal waters of Aklan, Negros Occidental, Capiz, Antique, Iloilo, and Guimaras In Aklan, coastal waters of Altavas, Batan and New Washington in Batan Bay
- Dagupan’s ‘Bangus King’ leads way for othersSotelo, Yolanda (Philippine Daily Inquirer, Inc., 2013-02-09)If there is someone who deserves to be called “Bangus King” here, it is Eduardo Maramba, who belongs to four generations of milkfish growers. “My great grandfather, Franciso, my grandfather, Cipriano, and my father, Rufino, were all engaged in bangus culture, but it is only during my time when the industry blossomed into its present state,” says Maramba, 58, who owns 8 hectares of fishpond in this city, 5 ha in Alaminos City and 12 fish cages also in Alaminos. Maramba, who is accredited by the Bureau of Fisheries and Aquatic Resources’ Ilocos office as a fish grower, saw how the industry grew. He started helping his father tend the family’s fishpond when he was 12 years old.
- Boracay's environmental woesAngelo, F. Allan L. (Daily Guardian Multi-Media Services, Inc., 2018-05-05)Some dimwits online and elsewhere are trying to make light of Boracay Island’s environmental problems by spewing fallacies. One hilarious fallacy or lie is that lumot or green algae that bloom in the island’s shoreline are a good indication and essential to the beach area because it is the main source of the famed white sand. What?! Any kid in elementary or high school will tell these dimwits that lumot or green algae serve as food for marine life and an indicator of ecological balance or the lack of it.