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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- Contrasting reproductive strategies between stress-tolerant and competitive coral taxaBonilla, K. G.; Guest, J. R.; Baria-Rodriguez, M. V. (Springer, 2023-04-19)Reproductive traits such as fecundity (i.e., the number of gametes produced) and the size and age of coral colonies at reproductive onset can vary in predictable ways among life history strategies. However, most studies on the onset of reproductive maturity in corals only report the presence or absence of oocytes with little known about variation in fecundity across size and age classes. This study aimed to determine the colony size and fecundity at the onset of reproductive maturity across size classes of two scleractinian corals with contrasting life history strategies, Acropora millepora (competitive) and Favites colemani (stress-tolerant). Colonies at a site in northwestern Philippines were sampled to determine the smallest colony size class with mature oocytes and to estimate fecundity across size classes. Histological slides were also prepared to verify the presence of mature gametes. Colonies were able to produce mature oocytes when they had attained colony diameters of 4.7 cm for A. millepora and 1.5 cm for F. colemani. A. millepora had lower fecundity, but larger oocytes compared to F. colemani. Although small colonies can contribute to the larval pool, the proportion of mature colonies increased for larger size classes, suggesting that larger colonies make a disproportionately greater contribution to population reproductive output. These findings contribute to our understanding of coral population dynamics, particularly in parameterizing population and demographic models for different coral life histories.
- Synthesis and biological evaluation of cyanobacterial-inspired peptidesCasanova, Jannelle R.; Villaraza, Aaron Joseph L.; Salvador-Reyes, Lilibeth (Philippine-American Academy of Science and Engineering, 2024-03-18)Cyanobacteria are known producers of structurally diverse and potent natural products; the majority are peptides with unique modifications. Yet, there remains a huge underexplored chemodiversity from cyanobacteria. Here, we designed a linear octapeptide as a product of combinatorial peptide design inspired by the natural products from the filamentous cyanobacteria Hapalosiphon welwitschii and Leptolyngbya sp. The target peptide was synthesized via solid-phase peptide synthesis (SPPS) using fluorenylmethyloxycarbonyl-protecting group (Fmoc) strategy. Structural diversity was expanded by the substitution of unnatural amino acids to yield five analogues. The structure and sequence of the synthesized peptides were confirmed using nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Biological activity evaluation was done; with none of the peptides showing antimicrobial or cytotoxic activities against microbial pathogens and mammalian cells, respectively. To our knowledge, this study is the first to report a combinatorial peptide design inspired by a natural product and a predicted biosynthetic product. This strategy of peptide design expands the chemistry of a known bioactive natural product with the aid of unexplored cyanobacterial biosynthetic gene clusters.
- Ontogenetic variability in the diel activity pattern of the marine gastropod Cassis cornuta(Mollusca: Cassidae)Calle, Lala Grace; Cabaitan, Patrick C; Sayco, Sherry Lyn G; Tan, Shau Hwai; Conaco, Cecilia (Oxford University Press, 2024-01-25)Examining activity patterns is essential in understanding gastropod feeding and movement ecology. However, the diel activity patterns of large-bodied gastropods, such as Cassis cornuta, remain poorly studied. Here, we conducted outdoor hatchery-based experiments to examine the diel activity patterns of C. cornuta adults and juveniles under natural sunlight and photoperiod. Activities of C. cornuta, such as crawling, hunting, feeding, burrowing and resting on the substratum, were examined every hour for 3 days. Although most individuals were inactive for a greater part of the observation period, active behaviours were recorded for some individuals during both daytime and nighttime, suggesting that C. cornuta is cathemeral, as supported by a nonsignificant result from a Rayleigh's test of uniformity. A higher proportion of adult and juvenile C. cornuta were inactive, either burrowed or resting on the substratum, during the 24-h period. Peak activity time for juveniles started at 20:00, with up to 50% of individuals active, while peak activity time for adults started at 21:00, with up to 20% of active individuals. Adults spent more time resting aboveground, whereas juveniles spent more time burrowed under the sand when not feeding. Juveniles hunted more frequently and spent more time feeding compared to adults. Additionally, juveniles crawled faster and were more successful in capturing sea urchins than adults. The information on variability in the diel activity patterns and movement rates between adult and juvenile C. cornuta would allow further demographic studies, and provide insights into possible conservation strategies for this species.
- Genetic connectivity and diversity between tropical and subtropical populations of the tropical horned sea star Protoreaster nodosus in the northwest PacificNakajima, Yuichi; Yasuda, Nina; Matsuki, Yu; Arriesgado, Dan M.; Fortes, Miguel D.; Uy, Wilfredo H.; Campos, Wilfredo L.; Nadaoka, Kazuo; Lian, Chunlan (Springer, 2024-06-01)Seagrass beds are ecologically and economically important coastal ecosystems, and seagrass-associated organisms are a key part of their biodiversity. Marine organisms that reproduce through broadcast spawning are likely to have less genetic differentiation among populations than those that use other modes of reproduction, but this has not been well studied. Here, we investigated the genetic diversity, genetic differentiation, and migration patterns of the seagrass-associated sea star Protoreaster nodosus across 12 sites spanning approximately 2500 km from the Ryukyu Archipelago, Japan, to the Philippines. We genotyped 405 individuals by using seven microsatellite loci and analyzed allelic richness and expected heterozygosity as indices of genetic diversity. Of these two indices, only expected heterozygosity decreased slightly with increasing latitude. These results suggest that genetic diversity has not clearly decreased, even in the isolated Ryukyu Archipelago populations. Geographic distance was significantly correlated with genetic differentiation (pairwise FST: − 0.005 to 0.049). However, populations in the Ryukyu Archipelago and the Philippines showed relatively low genetic structuring and the pairwise genetic differentiation between these regions was often non-significant. Analysis of historical migration rates showed bidirectional north–south migration, which appears to be influenced by the Kuroshio Current and its countercurrents.
- Decadal stability in coral cover could mask hidden changes on reefs in the East Asian SeasChan, Y. K. S.; Affendi, Y. A.; Ang, P. O.; Baria-Rodriguez, M. V.; Chen, C. A.; Chui, A. P. Y.; Glue, M.; Huang, H.; Kuo, C-Y.; Kim, S. W.; Lam, V. Y. Y.; Lane, D. J. W.; Lian, J. S.; Lin, S. M. N. N.; Lunn, Z.; Nañola, C. L.; Nguyen, V. L.; Park, H. S.; Sutthacheep, M.; Vo, S. T.; Vibol, O.; Waheed, Z.; Yamano, H.; Yeemin, T.; Yong, E.; Kimura, T.; Tun, K.; Chou, L. M.; Huang, D. (Springer, 2023-06-10)Coral reefs in the Central Indo-Pacific region comprise some of the most diverse and yet threatened marine habitats. While reef monitoring has grown throughout the region in recent years, studies of coral reef benthic cover remain limited in spatial and temporal scales. Here, we analysed 24,365 reef surveys performed over 37 years at 1972 sites throughout East Asia by the Global Coral Reef Monitoring Network using Bayesian approaches. Our results show that overall coral cover at surveyed reefs has not declined as suggested in previous studies and compared to reef regions like the Caribbean. Concurrently, macroalgal cover has not increased, with no indications of phase shifts from coral to macroalgal dominance on reefs. Yet, models incorporating socio-economic and environmental variables reveal negative associations of coral cover with coastal urbanisation and sea surface temperature. The diversity of reef assemblages may have mitigated cover declines thus far, but climate change could threaten reef resilience. We recommend prioritisation of regionally coordinated, locally collaborative long-term studies for better contextualisation of monitoring data and analyses, which are essential for achieving reef conservation goals.
- Hydrodynamics rather than type of coastline shapes self‐recruitment in anemonefishesSato, Masaaki; Honda, Kentaro; Nakamura, Yohei; Bernardo, Lawrence Patrick C.; Bolisay, Klenthon O.; Yamamoto, Takahiro; Herrera, Eugene C.; Nakajima, Yuichi; Lian, Chunlan; Uy, Wilfredo H.; Fortes, Miguel D.; Nadaoka, Kazuo; Nakaoka, Masahiro (Wiley, 2023-07-25)Many marine species have a pelagic larval phase that undergo dispersal among habitats. Studies on marine larval dispersal have revealed a large variation in the spatial scale of dispersal and self-recruitment. However, few studies have investigated the influence of types of coastline (e.g., bay vs. open coast) on marine larval dispersal. Bays or lagoons generally enhance the retention of larvae, while larvae are more likely to be flushed by strong currents in open coasts. To examine associations between larval dispersal, coastline type, and hydrodynamics, we compared fin-scale dispersal patterns, self-recruitment, and local retention (LR) of two anemonefishes (Amphiprion frenatus and Amphiprion perideraion) between a semi-enclosed bay and an open coast in the Philippines combining genetic parentage analysis and biophysical dispersal modeling. Contrary to our expectations, parentage analysis revealed lower estimates of self-recruitment in the semi-closed bay (0%) than in the open coast (14–15%). The result was consistent with dispersal simulations predicting lower LR and self-recruitment in the semi-closed bay (0.4% and 19%) compared to the open coast (2.9% and 38%). Dispersal modeling also showed that cross-shore currents toward offshore were much stronger around the semi-closed bay and were negatively correlated with LR and self-recruitment. These results suggest that stronger cross-shore currents around the semi-closed bay transport anemonefish larvae to the offshore and mainly contributed to the lower self-recruitment. Our results highlight importance of hydrodynamics on larval dispersal and difficulty in predicting self-recruitment from coastline type alone.
- 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.
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