National Committee on Marine Sciences (NCMS)
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- Evolutionary trends in large pelagic filter-feedersStiefel, Klaus M. (Informa UK Limited, 2020-01-16)This paper attempts a synthesis of the evolution of large pelagic filter-feeding animals from the Cambrian to the present. Lineages known or suspected to have evolved large pelagic filter-feeding species are, in the order of their appearance, stem euarthropods, agnathan fishes, nautiloid cephalopods, placoderms, sharks, bony fishes, reptiles, ammonite cephalopods, and mammals. I discuss evolutionary trends which are apparent from the evolution of the large pelagic filter-feeding niche, which are 1. a size increase relative to their ancestral species, 2. the transition between taxonomic groups giving rise to pelagic filter-feeders, with vertebrates dominating the post-Cambrian, 3. the evolution of large pelagic filter-feeders from large carnivores in most, but not all cases, and 4. lengthy gaps in the record of pelagic filter-feeders around four of the big five mass extinctions.
- Chemical profiling of the Arctic sea lettuce Ulva lactuca (Chlorophyta) mass-cultivated on land under controlled conditions for food applicationsRoleda, Michael Y.; Lage, Sandra; Aluwini, Daniel Fonn; Rebours, Céline; Brurberg, May Bente; Nitschke, Udo; Gentili, Francesco G. (Elsevier BV, 2021-03)The increasing use of seaweeds in European cuisine led to cultivation initiatives funded by the European Union. Ulva lactuca, commonly known as sea lettuce, is a fast growing seaweed in the North Atlantic that chefs are bringing into the local cuisine. Here, different strains of Arctic U. lactuca were mass-cultivated under controlled conditions for up to 10 months. We quantified various chemical constituents associated with both health benefits (carbohydrates, protein, fatty acids, minerals) and health risks (heavy metals). Chemical analyses showed that long-term cultivation provided biomass of consistently high food quality and nutritional value. Concentrations of macroelements (C, N, P, Ca, Na, K, Mg) and micronutrients (Fe, Zn, Co, Mn, I) were sufficient to contribute to daily dietary mineral intake. Heavy metals (As, Cd, Hg and Pb) were found at low levels to pose health risk. The nutritional value of Ulva in terms of carbohydrates, protein and fatty acids is comparable to some selected fruits, vegetables, nuts and grains.
- Assessing the viability of commercial media for the mass culture of Chaetoceros muelleriCabanayan-Soy, Rona; de Peralta, Glycinea; Juinio–Meñez, Marie Antonette (National Fisheries Research and Development Institute, 2021-12)The microalgae Chaetoceros muelleri is considered a highly nutritious feed for the cultured larvae of the tropical sea cucumber Holothuria scabra. Due to the cost of analytical grade culture media used in the production of C. muelleri, there is a need to evaluate cheap alternative commercial media to decrease the cost of producing quality live microalgal food. In this study, two different indoor batch culture systems (1 L glass bottles and 10 L plastic carboys) were used to evaluate the effectiveness of two conventional (modified F/2 and Walne’s) and one commercial (Epizyme AGP complete) microalgal culture media. Results of the 1 L glass bottle experiment showed that the peak cell density of C. muelleri in AGP (1,241 ± 116 x 104 cells ml-1) was not significantly different from the modified F/2 (1,584 ± 41 x 104 cells ml-1) and Walne’s medium (1,319 ± 162 x 104 cells ml-1) (Kruskal-Wallis test, p=0.78). Likewise, in the plastic carboy experiment, the maximum cell density of C. muelleri in Walne’s medium (750 ± 144 x 104 cells ml-1) and F/2 medium (653 ± 79 x 104 cells ml-1) were higher, but not significantly different from AGP (496 ± 184 x 104 cells ml-1) (Kruskal-Wallis test, p=0.43). The highest growth rate in the glass bottle cultures was the modified F/2 (0.38 div day-1), while AGP was the lowest (0.34 div. day-1). On the other hand, in carboy culture, AGP was higher (0.17 div.day-1) compared to modified F/2 (0.15 div. day-1) and Walne’s medium (0.13 div. day-1). The exponential growth phase was similar in the glass bottles, while in the carboy, the exponential phase was reached at a shorter time in the AGP treatment than those in the modified F/2 and Walne’s media. The findings showed that AGP medium is an adequate alternative to replace the conventional media (modified F/2 and Walne’s) during the secondary stock culture for C. muelleri. The viability of using cheaper and more readily available commercial AGP media for the indoor culture production of C. muelleri can contribute to cost-effective scaling-up of the hatchery production of quality H. scabra larvae and early juveniles.The authors would like to thank Dr. Rene Abesamis for his valuable comments and the two anonymous reviewers for their suggestions to improve the manuscript. We are also grateful for the guidance of Ms. Elsie Tech in improving the microalgal cultures and providing valuable inputs for 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. We would also like to acknowledge the Department of Science and Technology Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (DOST-PCAARRDQSR-MR-CUC.02.02) and the Australian Centre for International Agricultural Research (ACIAR – FIS/2003/059) for the financial support in the conduct of this study.
- Genetic differentiation and signatures of local adaptation revealed by RADseq for a highly dispersive mud crab Scylla olivacea (Herbst, 1796) in the Sulu SeaMendiola, Michael John R.; Ravago‐Gotanco, Rachel (Wiley, 2021-05-04)Connectivity of marine populations is shaped by complex interactions between biological and physical processes across the seascape. The influence of environmental features on the genetic structure of populations has key implications for the dynamics and persistence of populations, and an understanding of spatial scales and patterns of connectivity is crucial for management and conservation. This study employed a seascape genomics approach combining larval dispersal modeling and population genomic analysis using single nucleotide polymorphisms (SNPs) obtained from RADseq to examine environmental factors influencing patterns of genetic structure and connectivity for a highly dispersive mud crab Scylla olivacea (Herbst, 1796) in the Sulu Sea. Dispersal simulations reveal widespread but asymmetric larval dispersal influenced by persistent southward and westward surface circulation features in the Sulu Sea. Despite potential for widespread dispersal across the Sulu Sea, significant genetic differentiation was detected among eight populations based on 1,655 SNPs (FST = 0.0057, p < .001) and a subset of 1,643 putatively neutral SNP markers (FST = 0.0042, p < .001). Oceanography influences genetic structure, with redundancy analysis (RDA) indicating significant contribution of asymmetric ocean currents to neutral genetic variation (R2adj = 0.133, p = .035). Genetic structure may also reflect demographic factors, with divergent populations characterized by low effective population sizes (Ne < 50). Pronounced latitudinal genetic structure was recovered for loci putatively under selection (FST = 0.2390, p < .001), significantly correlated with sea surface temperature variabilities during peak spawning months for S. olivacea (R2adj = 0.692–0.763; p < .050), suggesting putative signatures of selection and local adaptation to thermal clines. While oceanography and dispersal ability likely shape patterns of gene flow and genetic structure of S. olivacea across the Sulu Sea, the impacts of genetic drift and natural selection influenced by sea surface temperature also appear as likely drivers of population genetic structure. This study contributes to the growing body of literature documenting population genetic structure and local adaptation for highly dispersive marine species, and provides information useful for spatial management of the fishery resource.This project was funded by the Department of Science and Technology—Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development (DOST-PCAARRD project no. QSR-IA-MCR.05.01), and implemented by the University of the Philippines—Marine Science Institute (UP-MSI). MJM acknowledges support provided by the DOST-Accelerated Science and Technology Human Resource Development Program (ASTHRDP; Thesis Grant) and the UP-MSI (Thesis Writing Grant). We are deeply thankful to Dr. Evangeline Magdaong, Jeniffer De Maligaya, and Benedict Castro of the Physical Oceanography Laboratory, UP-MSI headed by Dr. Cesar Villanoy for the larval dispersal biophysical modeling, Angela Camille Aguila and Simon Alcantara for laboratory assistance, Bhenjamin Ona for the remote sensing data, Dr. Din Matias for analysis recommendations, Von Yip for QGIS assistance, and Dr. Richard Mualil and Yunadzmal Ong of Mindanao State University (MSU Tawi-Tawi) for sample collection. We also thank Sharon Magnuson and Chris Bird (Genomics Core Lab, Texas A&M University, Corpus Christi) for performing the RAD sequencing. We thank the reviewers whose comments and insights greatly improved the manuscript. This is MSI contribution number 483.
- Precipitation stable isotopic signatures of tropical cyclones in Metropolitan Manila, Philippines, show significant negative isotopic excursionsJackisch, Dominik; Yeo, Bi Xuan; Switzer, Adam D.; He, Shaoneng; Cantarero, Danica Linda M.; Siringan, Fernando P.; Goodkin, Nathalie F. (Copernicus GmbH, 2022-01-28)Tropical cyclones have devastating impacts on the environment, economies, and societies and may intensify in the coming decades due to climate change. Stable water isotopes serve as tracers of the hydrological cycle, as isotope fractionation processes leave distinct precipitation isotopic signatures. Here we present a record of daily precipitation isotope measurements from March 2014 to October 2015 for Metropolitan Manila, a first-of-a-kind dataset for the Philippines and Southeast Asia. We show that precipitation isotopic variation at our study site is closely related to tropical cyclones. The most negative shift in δ18O values (−13.84 ‰) leading to a clear isotopic signal was caused by Typhoon Rammasun, which directly hit Metropolitan Manila. The average δ18O value of precipitation associated with tropical cyclones is −10.24 ‰, whereas the mean isotopic value for rainfall associated with non-cyclone events is −5.29 ‰. Further, the closer the storm track is to the sampling site, the more negative the isotopic values are, indicating that in situ isotope measurements can provide a direct linkage between isotopes and typhoon activities in the Philippines.This research was supported by the Earth Observatory of Singapore (EOS) via its funding from the National Research Foundation Singapore and the Ministry of Education of Singapore under the Research Centres of Excellence initiative. This work comprises EOS contribution no. 422. This study is also the part of the IAEA Coordinated Research Project (CRP code: F31004) on “Stable Isotopes in Precipitation and Paleoclimatic Archives in Tropical Areas to Improve Regional Hydrological and Climatic Impact Models” (IAEA Research Agreement no. 17980).
- Preliminary population genomic study on the sandfish Holothuria (Metriatyla) scabraLal, Monal M.; Macahig, Deo A. S.; Brown, Kelly T.; Juinio‐Meñez, Marie A.; Southgate, Paul C.; Ravago‐Gotanco, Rachel (Wiley, 2021-07-04)Brief note.
- Feasibility of early outplanting of sexually propagated Acropora verweyi for coral reef restoration demonstrated in the PhilippinesLigson, Charlon A.; Tabalanza, Tracy D.; Villanueva, Ronald D.; Cabaitan, Patrick C. (Wiley, 2019-11-20)Over the last 20 years, coral sexual propagation techniques for reef restoration have been steadily developed and improved. However, these techniques involve considerable time and costs to grow coral propagules. There is a need to examine the optimal size of juvenile corals for outplantation. Here, we outplanted sexually propagated small (3–5 mm diameter) and large (10–15 mm diameter) Acropora verweyi corals at 4 months after fertilization at two sites in northwestern Philippines, and compared their survival and radial growth rate after a year. A. verweyi coral juveniles (n = 240) exhibited an overall mean survival of 29.5% and growth rate of 11.12 ± 6.2 mm/year (mean ± SD). Large colonies had a significantly higher growth rate than smaller colonies. Although survivorship of large juveniles was significantly better than that of the smaller ones at one site, it did not differ significantly at the other. Each 4-month-old coral cost US$1.52 to produce, while the cost of each of the outplanted juveniles (n = 240) was about US$2.67, whereas the cost of each survivor about a year after outplantation was US$11.47. Results suggest that A. verweyi reared in ex situ nurseries for only 4 months can survive reasonably well when outplanted onto coral reefs.
- Influence of light, water motion, and stocking density on the growth and pigment content of Halymenia durvillei (Rhodophyceae) under laboratory conditionsRula, Najeen Arabelle M.; Ganzon-Fortes, Edna T.; Pante, Ma. Josefa R.; Trono, Gavino C. (Springer, 2021-05-17)The tropical red seaweed Halymenia durvillei Bory de Saint Vincent is a potential source of the high-value pigments, r-phycoerythrin (RPE) and r-phycocyanin (RPC). The unique properties of these pigments find many applications—from food to cosmetics, pharmaceuticals, and biomedical research. This study aimed to improve the land-based culture technology of H. durvillei by determining the appropriate combination of light, water motion, and stocking density that would result in high growth performance and high RPE and RPC content. Combinations of two light levels (full light, 100% and reduced light, 67%), two water motion levels (low and moderate), and three stocking densities (50, 100, and 200 g) were studied using 64.5-L glass tanks with flow-through seawater and aeration systems at the outdoor land-based seaweed nursery in Bolinao, Pangasinan, Philippines. After 6 weeks of culture, growth performance (growth rate and productivity) of H. durvillei and phycobiliprotein content were best under a combination of full light (100%), moderate water motion, and 50-g stocking density. The generally low light regime during the experimental period, which coincided with the cold, dry season characterized by shorter days and overcast skies, may have influenced H. durvillei to maximize the use of available resources such as light and possible increased nutrient availability from water motion to promote growth and phycobiliprotein synthesis. Treatments with low stocking densities generally showed satisfactory growth and phycobiliprotein content. This study provides groundwork for future research into mechanisms by which these and other factors affect the growth and physiology of H. durvillei in culture.
- Summer heatwave impacts on the European kelp Saccharina latissima across its latitudinal distribution gradientDiehl, Nora; Roleda, Michael Y.; Bartsch, Inka; Karsten, Ulf; Bischof, Kai (Frontiers Media SA, 2021-10-11)Kelps are important foundation species in coastal ecosystems currently experiencing pronounced shifts in their distribution patterns caused by ocean warming. While some populations found at species’ warm distribution edges have been recently observed to decline, expansions of some species have been recorded at their cold distribution edges. Reduced population resilience can contribute to kelp habitat loss, hence, understanding intraspecific variations in physiological responses across a species’ latitudinal distribution is crucial for its conservation. To investigate potential local responses of the broadly distributed kelp Saccharina latissima to marine heatwaves in summer, we collected sporophytes from five locations in Europe (Spitsbergen, Bodø, Bergen, Helgoland, Locmariaquer), including populations exposed to the coldest and warmest local temperature regimes. Meristematic tissue from sporophytes was subjected to increasing temperatures of Δ+2, Δ+4 and Δ+6°C above the respective mean summer temperatures (control, Δ±0°C) characteristic for each site. Survival and corresponding physiological and biochemical traits were analyzed. Vitality (optimum quantum yield, Fv/Fm) and growth were monitored over time and biochemical responses were measured at the end of the experiment. Growth was highest in northern and lowest in southern populations. Overall, northern populations from Spitsbergen, Bodø and Bergen were largely unaffected by increasing summer temperatures up to Δ+6°C. Conversely, sporophytes from Helgoland and Locmariaquer were markedly stressed at Δ+6°C: occurrence of tissue necrosis, reduced Fv/Fm, and a significantly elevated de-epoxidation state of the xanthophyll cycle (DPS). The variations in phlorotannins, mannitol and tissue C and N contents were independent of temperature treatments and latitudinal distribution pattern. Pronounced site-specific variability in response to increasing temperatures implies that exceeding a threshold above the mean summer temperature exclusively affect rear-edge (southernmost) populations.Abiotic temperature data used in this manuscript were produced with the Giovanni online data system, developed and maintained by the NASA GES DISC. Sampling in France was conducted in accordance with the French legislation on the Access to Genetic Resources and Benefit-Sharing. We also acknowledge the MODIS mission scientists and associated NASA personnel for the production of the data used in this research effort. This study has been conducted at the Alfred Wegener Institute for Polar and Marine Research (AWI), Bremerhaven and at the AWIPEV Research Station in Ny-Ålesund, Svalbard. We are grateful to the station staff of AWIPEV for support and logistics and to the scientific diving teams on Spitsbergen and Helgoland for sampling. We thank A. Wagner (AWI) for sampling support on Helgoland and his support in the setting up of the experiments, and also J. Müller (University of Rostock) for running the C:N analyzer. B. Meyer-Schlosser (University of Bremen) supported sampling and pigment analyses.
- Linking thallus morphology with P-I curves of 50 macrobenthic algae from Bolinao, Pangasinan, PhilippinesSaco, Jayvee; Ganzon-Fortes, Edna (Science and Technology Information Institute, 2022-08-04)This study demonstrated that thallus morphology could affect a species' capacity to utilize light for photosynthesis and, hence, will affect its productivity. Fifty (50) macroalgal species collected from an intertidal habitat in Bolinao, Pangasinan, Philippines were grouped into five "functional-forms" based on their inferred productivity: functional-form group (FFG) A: very thin tubes/sheets/strips, FFG B: thin sheets/delicately branched, FFG C: medium-thick blade/coarsely branched with dense ramuli, FFG D: heavily thick branches/segments or with moderate calcification, and FFG E: heavily calcified. Their photosynthesis-irradiance (P-I) curves were determined through the measurement of oxygen evolved in a closed system after 1-h incubation under six different light treatments. P-I curve parameters such as P n max , I k , I c , α, and R d were assessed to determine the groups' physiological responses to light. The thickness of thallus blades, coarseness of branches, complex branching, and calcification appeared to lessen photosynthetic capacity, as shown by the significantly decreasing trend of P n max from FFGs A-E. FFG A also showed the steepest slope (highest mean α value) compared with the rest of the functional-form groups, indicating their efficiency to utilize low light for photosynthesis. Light saturation and compensation values were less distinct in differentiating the functional form groups, probably because the seaweeds examined were all collected from the same shallow intertidal zone, suggesting their acclimation to similar photon flux densities. Results from this study fit the prediction of the function form hypothesis for seaweeds quite well.Appreciation is extended to: [1] the Philippine Council for Aquatic, Agricultural, and Natural Resources Research and Development of the Department of Science and Technology as thesis grant to the first author; [2] the UP-CS-MSI research grant to the second author; [3] the Commission on Higher Education for the financial support; and [4] the staff of the Bolinao Marine Laboratory, UP-MSI, and the Batangas State University for their assistance. Helpful critics and recommendations from Dr. Rhodora Azanza and Dr. Wilfredo Uy are acknowledged, most especially to the late Dr. Ronald Villanueva, to whom this paper is wholeheartedly dedicated. Also, deep appreciation is extended to the reviewers for greatly improving the manuscript of this paper.