11. University of the Philippines - Marine Science Institute (UP - MSI)

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University of the Philippines - Marine Science Institute (UP - MSI) - Philippines - contributions to address the Ocean Decade Challenges

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17-year change in species composition of mixed seagrass beds around Santiago Island, Bolinao, the northwestern Philippines
Tanaka, Yoshiyuki; Go, Gay Amabelle; Watanabe, Atsushi; Miyajima, Toshihiro; Nakaoka, Masahiro; Uy, Wilfredo H.; Nadaoka, Kazuo; Watanabe, Shuichi; Fortes, Miguel D. (Elsevier, 2014)
Effects of fish culture can alter the adjacent ecosystems. This study compared seagrass species compositions in 2012 with those in 1995, when fish culture was less intensive compared to 2012 in the region. Observations were conducted at the same four sites around Santiago Island, Bolinao: (1) Silaqui Island, (2) Binaballian Loob, (3) Pislatan and (4) Santa Barbara, and by using the same methods as those of Bach et al. (1998). These sites were originally selected along a siltation gradient, ranging from Site 1, the most pristine, to Site 4, a heavily silted site. By 2012, fish culture had expanded around Sites 2, 3 and 4, where chlorophyll a (Chl a) was greater in 2012 than in 1995 by one order of magnitude. Enhalus acoroides and Cymodocea serrulata, which were recorded in 1995, were no longer present at Site 4, where both siltation and nutrient load are heavy.
A multi-framework analysis of stakeholders’ perceptions in developing a localized blue carbon ecosystems strategy in Eastern Samar, Philippines
Quevedo, Jay Mar D.; Ferrera, Charissa M.; Faylona, Marie Grace Pamela G.; Kohsaka, Ryo (Springer Science and Business Media LLC, 2024-01-25)
Blue carbon ecosystems (BCEs) are vital for global climate change mitigation and offer diverse local ecosystem co-benefits. Despite existing literatures on integrating national and international BCE agendas at the local level, the development and implementation of localized BCE strategies often lag behind. To provide insights on this knowledge gap, we present a case study conducted in Eastern Samar, Philippines. Employing a multi-framework analysis- encompassing DPSIR (drivers, pressures, state, impact, responses), SOAR (strengths, opportunities, aspirations, results), and PESTLE (political, economic, social, technological, legal, environmental) frameworks, stakeholder perceptions collected from focus group discussions highlight issues and challenges in developing and implementing a BCE strategy. Findings reveal that the aftermath of Typhoon Haiyan in 2013 in the study sites stimulated conservation efforts and raised awareness, but governance structures and policy enforcement influence the success and longevity of management and conservation efforts. Through the integration of multiple frameworks, this study outlined a potential localized BCE strategy, emphasizing both internal priorities such as stakeholder engagement and alternative livelihoods and external priorities related to policy and technological supports. While developed based on a specific case study in the Philippines, the proposed strategy is presented in a general manner, enabling its potential replication in other provinces in the Philippines or in countries with similar geographic settings.
Accumulation and exposure classifications of plastics in the different coastal habitats in the western Philippine archipelago
Gomez, Norchel Corcia F.; Cragg, Simon M.; Ghiglione, Jean-François; Onda, Deo Florence L. (Elsevier, 2023-11)
Studies consistently ranked the Philippines as one of the top contributors of plastic wastes leaking into the ocean. However, most of these were based on probabilities and estimates due to lack of comprehensive ground-truth data, resulting also in the limited understanding of the contributing factors and drivers of local pollution. This makes it challenging to develop science-driven and locally-contextualized policies and interventions to mitigate the problem. Here, 56 sites from different coastal habitats in the western Philippine archipelago were surveyed for macroplastics standing stock, representing geographic regions with varying demography and economic activities. Clustering of sites revealed three potential influencing factors to plastic accumulation: population density, wind and oceanic transport, and habitat type. Notably, the amount and types of dominant plastics per geographic region varied significantly. Single-use plastics (food packaging and sachets) were the most abundant in sites adjacent to densely populated and highly urbanized areas (Manila Bay and eastern Palawan), while fishing-related materials dominated in less populated and fishing-dominated communities (western Palawan and Bolinao), suggesting the local industries significantly contributing to the mismanaged plastics in the surveyed sites. Meanwhile, isolated areas such as islands were characterized by the abundance of buoyant materials (drinking bottles and hygiene product containers), emphasizing the role of oceanic transport and strong connectivity in the oceans. Exposure assessment also identified single-use and fishing-related plastics to be of “high exposure (Type 4)” due to their high abundance and high occurrence. These increase their chances of encountering and interacting with organisms and habitats, thus, resulting into more potential harm. This study is the first comprehensive work done in western Philippines, and results will help contextualize local pollution, facilitating more effective management and policymaking.
Aspects of the growth, recruitment, mortality and reproduction of the scallop Amusium pleuronectes (Linné) in the Lingayen Gulf, Philippines
Del Norte, A. G. C. (Informa UK Limited, 1988-11)
Growth, recruitment, mortality and reproduction were investigated in the Asian moon scallop, Amusium pleuronectes (Linne) from the Lingayen Gulf, Philippines. Allometric relationships were defined by comparing different shell dimensions, as well as body weight proportions including total weight with shell, visceral weight, adductor muscle weight and gonad weight. Use of the von Bertalanffy-based ELEFAN I program yielded estimates of growth parameters equivalent to H ∞ = 106Dimshell height and K = 0.92 per year, with approximate longevity for the species of about 2 years. Recruitment, as derived using the ELEFAN II program, occurred throughout the year, but showed a pattern consisting of one major and one minor pulse separated by an 8- and 4-months interval. Fishing mortality (F = 5.3) was higher than natural mortality (M = 1.9). Spawning occurred throughout the year, with one major peak in February and one minor peak between July and September, thereby providing some biological basis to the recruitment pattern indicated. Protandry and size at sexual maturity (54 mm) in the species were confirmed.
Assessing the efficiency of microplastics extraction methods for tropical beach sediments and matrix preparation for experimental controls
Bonita, Jan Danielle P.; Gomez, Norchel Corcia F.; Onda, Deo Florence L. (Frontiers Media SA, 2023-11-03)
Introduction: Microplastic pollution has become a global issue, eliciting attention not just from the scientific community but also both from the public and governmental bodies. Drawing data-driven policies and interventions, however, remain difficult due to the severely lacking baseline information from different environments such as beaches. One of the challenges in doing baseline studies is the lack of harmonized methodologies that will allow for comparison of results, integration of data, and its effective translation to evidence-based policies. Emphasis on quality control measures among baselining efforts through the proper implementation of experimental controls is also lacking. Methodology: To address these gaps, we compared methodologies for preparing the sediment matrix for experimental controls, as well as evaluated protocols for extracting microplastics from tropical beach sediments. Beach sediments were collected, dried, sieved, and spiked with known amounts of microplastics of different polymer types. The removal and extraction efficiencies of the protocols being compared were evaluated. Results and discussion: Our results showed that subjecting beach sediments to a furnace at 550° C for 4 hours is the most efficient way to remove plastic contamination, implying its applicability for preparing experimental controls. Meanwhile, a modified version of Masura et al. (2015), one of the widely cited methodologies for microplastics extraction, exhibited the highest mean extraction efficiency (99.05 ± 0.82%) among the protocols being compared. Results of this work will be useful in identifying methods that can be adopted and utilized for research and baselining efforts not just in the Philippines but also in Southeast Asia. This will also be helpful in the harmonization of methods, data reporting, and even skills as implemented through the regional and national action plans to address marine plastic pollution.
Asterocladon ednae sp. nov. (Asterocladales, Phaeophyceae) from the Philippines
Sasagawa, Eriko; Santiañez, Wilfred John E.; Kogame, Kazuhiro (Wiley, 2022-06-21)
Members of the brown algal order Asterocladales are characterized by stellate arrangement of its chloroplasts, in which a stellate configuration has a protruding central pyrenoid complex. The order is represented by the genus Asterocladon, which consists of only three species so far. Similar to other small and filamentous seaweeds, studies on Asterocladon remain scant and their diversity poorly understood. To fill this gap, we conducted molecular-assisted taxonomic studies on Asterocladon based on seven culture isolates collected from Okinawa Prefecture, Japan and Cebu, the Philippines. One culture isolate from the Philippines was revealed to be a new species of Asterocladon based on morpho-anatomical and molecular analyses using rbcL and psaA genes and is described here as Asterocladon ednae. The other isolates were attributed to A. rhodochortonoides. A. ednae was most closely related to A. rhodochortonoides in morphology and molecular phylogeny but was distinguished from the latter by its elongately ellipsoid plurilocular sporangia. This is the first report of the genus and species A. ednae in the Philippines, further increasing the diversity of seaweeds in the country.
Attachment of potential cultivable primo-colonizing bacteria and its implications on the fate of low-density polyethylene (LDPE) plastics in the marine environment
Bitalac, 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.
Benthic energy dynamics in a southern Baltic ecosystem
Yap, H. T. (Springer, 1991-10)
Benthic components and metabolic activity at two stations in the Darss-Zingst estuary (eastern German Baltic coast) were investigated over a seasonal cycle from April 1985 to August 1986. As has been established for temperate and boreal ecosystems, peaks in the biomass of benthic microphytes occurred in the spring and late autumn to winter, presumably caused by settling phytoplankton blooms. Metabolic activity of the benthos did not increase with rising ambient temperatures. Rather, the highest values of oxygen consumption were recorded during the cooler months (spring and winter), when increased numbers of organisms were also observed. This may be a response to a greater food supply to the sediment in the form of settling phytoplankton during these times of year.
Characteristics of marine heatwaves in the Philippines
Edullantes, Brisneve; Concolis, Brenna Mei M.; Quilestino-Olario, Raven; Atup, Dale Patrick D.; Cortes, Aiza; Yñiguez, Aletta T. (Elsevier, 2023-09)
Marine Heatwaves (MHWs) are prolonged, discrete, and anomalously warm events, which have recently gained global attention due to their far-reaching effects and reported impacts. Although intensive studies have been carried out at global and regional scales, these events remained understudied in the Philippines – a country with high marine biodiversity. The Philippines is highly vulnerable to the impacts of these extreme events as it lies in the western boundary of the Pacific that is considered as a hotspot for MHWs. The present study used multi-year climatic sea surface temperature (SST) record to detect MHWs in the Philippines. The detected events were then characterized using the standardized metrics. Linear trend analysis was conducted to determine the magnitude and direction of the change of the MHW metrics over time. Decadal trend revealed that MHWs in the Philippines significantly increased from seven MHWs in the 1980s to 37 MHWs in the last decade. Moreover, increased duration was remarkable in 2020 with 276 MHW days. MHW frequency and duration were increasing at a rate almost twice as its neighboring waters. Intensities did not significantly increase with time, but the highest SST anomaly is associated with El Niño Southern Oscillation. Furthermore, the eastern and western region of the Philippines is vulnerable to MHWs, but hotspots are mostly confined in the West Philippine Sea and western tropical Pacific. An in-depth investigation of the drivers of MHWs is recommended to understand the physical mechanisms of the development of these extreme thermal events in the Philippine seas. The findings have significant implications for coastal marine resource management, highlighting the need for adaptive management strategies and increased monitoring and research efforts to mitigate the impacts of MHWs on marine ecosystems and local economies in the Philippines.
Clay minerals control silicon isotope variations of fine-grained river sediments: Implication for the trade-off between physical erosion and chemical weathering
Ling, Chen; Liu, Zhifei; Yu, Xun; Zhao, Yulong; Siringan, Fernando P.; Le, Khanh Phon; Sathiamurthy, Edlic; You, Chen-Feng; Chen, Kaiyun (Elsevier, 2024)
Stable silicon (Si) isotopes in fluvial sediments can provide insights into understanding silicate weathering processes on the Earth's surface. However, a lack of comprehensive studies has hindered full understanding of the factors influencing Si isotope fractionation during continental weathering. In this study, through the analysis of Si isotopes in fine-grained sediments from 13 rivers surrounding the South China Sea, significant variation of Si isotopes in bulk detrital sediments (<63 μm) was observed, with δ30Si values ranging from −0.17‰ to −1.09‰. At basin scale, the δ30Si values are influenced by multiple controlling factors such as climatic conditions, lithology, and tectonic settings, which have a close relationship with the content of clay minerals. The characteristics of weathering types and intensities are ultimately reflected in the weathering products, specifically clay minerals. Compiling data across multiple grain sizes from major rivers globally, robust correlations based on clay mineral classification between δ30Si and Al/Si ratio have been observed, which are unaffected by regional and grain-size variations. As the dominant clay mineral group transitions from illite/chlorite to smectite and kaolinite, the degree of Si isotope fractionation increases progressively. This sequence indicates a shift from stronger physical erosion to more intensive chemical weathering, suggesting a transition in the weathering regime from weathering-limited to transport-limited. This study reveals the intrinsic link between Si isotopic compositions and clay mineral assemblages, providing implications for similar stable isotope research and offering a potential indicator for understanding continental weathering processes and their contributions to the global carbon cycle.
Co-occurrence of a marine heatwave and a reported tomato jellyfish (Crambione mastigophora Maas, 1903) bloom in March 2020 at El Nido, Palawan, Philippines
Quilestino-Olario, Raven; Concolis, Brenna Mei M.; Atup, Dale Patrick D.; Cortes, Aiza; Yñiguez, Aletta T.; Edullantes, Brisneve (The Plankton Society of Japan/The Japanese Association of Benthology, 2023-05-31)
Globally, observations on marine species during marine heatwaves (MHWs) help outline the scope of the MHW’s possible biological effects. In line with this effort, this paper presents a 2020 MHW that coincided with a reported ‘tomato jellyfish’ (Crambione mastigophora Maas, 1903) bloom on 23 March 2020 in the Corong-Corong Bay of Palawan, Philippines. Detecting a moderate MHW from 21 March to 04 April 2020, the analysis of sea surface temperatures revealed that most areas surrounding the bloom site attained their peak positive anomalies on the same day as the reported bloom. Certain physical mechanisms present in the first quarter of 2020 may have played a role in the occurrence of both events: the presence of cyclonic eddies and parallel monsoonal winds alongshore can induce upwelling which promotes biological productivity in surface waters, while the observed weakening of winds have been associated with anomalous warming of the sea surface. Further studies are still highly recommended to determine the exact causes of the jellyfish bloom and what conditions make it more likely to happen during MHWs. However, if the C. mastigophora is hypothetically able to continually bloom amidst warming temperatures, the increasing trend of MHW frequency and intensity in the West Philippine Sea (where the reported bloom site is situated) may consequently yield more future co-occurrences. This paper aims to hopefully contribute to the existing knowledge of possible biological impacts associated with extreme marine events, especially in the Philippine context where both jellyfish blooms and MHWs are understudied.
Comprehensive metabolomics of Philippine Stichopus cf. horrens reveals diverse classes of valuable small molecules for biomedical applications
Torreno, Vicenzo Paolo M.; Molino, Ralph John Emerson J.; Junio, Hiyas A.; Yu, Eizadora T. (Public Library of Science (PLoS), 2023-12-06)
Stichopus cf. horrens is an economically important sea cucumber species in Southeast Asia due to their presumed nutritional and medicinal benefits. However, compared to other sea cucumbers such as Apostichopus japonicus, there are no biochemical studies on which compounds contribute to the purported bioactivities of S. cf. horrens. To address this, a high-throughput characterization of the global metabolite profile of the species was performed through LC-MS/MS experiments and utilizing open-access platforms such as GNPS, XCMS, and metaboAnalyst. Bioinformatics-based molecular networking and chemometrics revealed the abundance of phospholipids such as phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), phosphatidylinositols (PIs), and phosphatidylserines (PSs) in the crude samples. Body wall extracts were observed to have higher levels of structural, diacylated PCs, while the viscera have higher relative abundance of single-tail PCs and PEs that could be involved in digestion via nutrient absorption and transport for sea cucumbers. PEs and sphingolipids could also be implicated in the ecological response and morphological transformations of S. cf. horrens in the presence of predatory and other environmental stress. Interestingly, terpenoid glycosides and saponins with reported anti-cancer benefits were significantly localized in the body wall. The sulfated alkanes and sterols present in S. cf. horrens bear similarity to known kairomones and other signaling molecules. All in all, the results provide a baseline metabolomic profile of S. cf. horrens that may further be used for comparative and exploratory studies and suggest the untapped potential of S. cf. horrens as a source of bioactive molecules.
Contrasting reproductive strategies between stress-tolerant and competitive coral taxa
Bonilla, 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.
Creation of an international laboratory network towards global microplastics monitoring harmonisation
Bakir, Adil; McGoran, Alexandra R.; Silburn, Briony; Russell, Josie; Nel, Holly; Lusher, Amy L.; Amos, Ruth; Shadrack, Ronick S.; Arnold, Shareen J.; Castillo, Cecy; Urbina, Joaquin F.; Barrientos, Eduardo; Sanchez, Henry; Pillay, Keshnee; Human, Lucienne; Swartbooi, Tarryn; Cordova, Muhammad Reza; Sani, Sofia Yuniar; Wijesinghe, T. W. A. Wasantha; Amarathunga, A. A. Deeptha; Gunasekara, Jagath; Somasiri, Sudarshana; mahatantila, Kushani; Liyanage, Sureka; Müller, Moritz; Hee, Yet Yin; Onda, Deo Florence; Jansar, Khairiatul Mardiana; Shiraz, Zana; Amir, Hana; Mayes, Andrew G. (Nature Research, 2024-06-03)
Infrastructure is often a limiting factor in microplastics research impacting the production of scientific outputs and monitoring data. International projects are therefore required to promote collaboration and development of national and regional scientific hubs. The Commonwealth Litter Programme and the Ocean Country Partnership Programme were developed to support Global South countries to take actions on plastics entering the oceans. An international laboratory network was developed to provide the infrastructure and in country capacity to conduct the collection and processing of microplastics in environmental samples. The laboratory network was also extended to include a network developed by the University of East Anglia, UK. All the laboratories were provided with similar equipment for the collection, processing and analysis of microplastics in environmental samples. Harmonised protocols and training were also provided in country during laboratory setup to ensure comparability of quality-controlled outputs between laboratories. Such large networks are needed to produce comparable baseline and monitoring assessments.
Decadal stability in coral cover could mask hidden changes on reefs in the East Asian Seas
Chan, 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.
Declining population of giant clams (Cardiidae:Tridacninae) in Palawan, Philippines
Dolorosa, Roger G.; Mecha, Niño Jess Mar F.; Bano, Jemima D.; Ecube, Krizia Meryl A.; Villanueva, Elmer G.; Cabaitan, Patrick C. (FapUNIFESP (SciELO), 2024)
For more than two decades, the Philippine government has protected the giant clams (Bivalvia: Cardiidae: Tridacninae) from exploitation and trade. However, there still is lack of information on the impact of these protective measures in conserving the species richness and density, especially in Palawan, the country’s last stronghold of these reef-associated bivalves. Hence, to assess the species richness and density of giant clams in Palawan, we conducted 57 photo-transect surveys in six sites covering 12,325 m 2. Out of these transect, 15 measured 5 × 25 m and the rest measured 5 × 50 m. For historical trends in the population of giant clams in Palawan, we used six published papers obtained from online platforms, 13 reports, and five undergraduate theses archived in local libraries. Information derived from recent field surveys indicated high variations in species richness (2 to 5 species) and densities (0.1 to > 3.6 ind.100 m -2). Historical data starting from 1984, including recent fieldwork, indicated very low densities and a declining trend. The current status suggests that giant clam populations’ viability and the reefs’ health are threatened. Effective mechanisms are needed to safeguard and enhance the remaining giant clam populations.
Development of autonomous multi-sensor ocean monitoring instrument designed for complex archipelagic waters
Purba, Noir P.; Faizal, Ibnu; Valino, Darryl Anthony; Kang, Hooi Siang; Sugianto, Erik; martasuganda, marine kenzi; Abimanyu, A.; Bratasena, T.; Zenyda, K. S.; Prayogo, N.; Ramdhani, F.; Khan, A. M. A. (Springer, 2023-01-22)
This paper presents the development of low-cost multi-sensor ocean monitoring instrument to measure oceanographic parameters. The aim of this instrument is to fulfil the monitoring specifically for archipelagic countries with complex waters, and it allows for both vertical and horizontal measurements. The platform contains removable sensors, rechargeable batteries, satellite system, and micro-controller. Inside the instrument, the probes are primarily to measure acidity level (pH), water temperature (°C), salinity (ppt), conductivity (ms/cm), turbidity (NTU), and depth (m). Furthermore, data are stored in an internal SD card and simultaneously transmitted to a website portal data via satellite after it goes to the surface water. For validation, several tests had been conducted in controlled laboratory conditions and field setting, in which the test results had shown satisfactory results. In the future, the system will be upgraded by adding extra units of antenna, chlorophyll sensors, and a power changer made from thrusters. Currently, this instrument is operational and available for use in archipelagic countries with dynamics depth.
Diurnal and diel patterns in the photosynthetic performance of the agarophyte Gelidiella acerosa
Ganzon-Fortes, E. T. (Walter de Gruyter, 1997)
Photosynthesis of the red alga Gelidiella acerosa was monitored on diurnal (during the day) and diel (24 h period) bases using the oxygen evolution technique in a closed system. Natural sunlight and artificial light were used to assess uniformity in the diurnal photosynthetic responses. Photosynthesis-irradiance (P-I) curves were also determined diurnally. On a diel basis, maximal photosynthetic rates occurred at day time and minimal rates occurred at night. Diurnally, photosynthesis fluctuated in different patterns depending on PFDs used. Under saturating but not photoinhibiting FFDs, photosynthesis exhibited an early morning minimum (a few hours after sunrise), a midday-noon maximum, sustained until late afternoon, then declined at or after sunset. However, when exposure to high PFDs (above 1200 μιηοΐ photons m"~s") were prolonged, i.e. from morning until afternoon, the photosynthetic performance suffered a depression starting from noon and persisting until afternoon. When PFDs lowered late in the afternoon, recovery of photosynthetic performance commenced resulting in increased photosynthetic rates. The P-I curve data corroborate findings of experiments using saturating but not photoinhibiting PFDs. The morning P-I curve had lower Pm and alpha, and higher Ik and Is values than the identical noon and afternoon P-I curves. This suggested that photosynthetic performance was yet inefficient in the morning but performed efficiently near midday until the afternoon. An endogenous circadian clock was implicated to have influenced the diurnal and diel patterns in the photosynthetic performance of G. acerosa. Photoinhibition was the other factor suspected to have altered the diurnal pattern.
Diversity and novelty of venom peptides from Conus (Asprella) rolani revealed by analysis of its venom duct transcriptome
Taguchi, Ryoichi; Masacupan, Dan Jethro; Lluisma, Arturo (Philippine-American Academy of Science and Engineering, 2024-04-22)
Conus species in the sub-genus Asprella are poorly studied because they inhabit deep-water habitats. To date, only a few peptides have been characterized from this clade. In this study, the venom duct transcriptome of a member of this clade, Conus rolani, was mined for potential conopeptides. Using a highthroughput RNA sequencing platform (Illumina) and a multiple k-mer de novo assembly, we found 103 putative conopeptide precursor amino acid sequences, including the few peptides previously reported for this species. The sequences, predominantly novel based on amino acid sequence, were diverse, comprising 36 gene superfamilies (including the “unassigned” superfamilies). As observed in other Conus species, the O1 gene superfamily was the most diverse (12 distinct sequences) but interestingly none of the sequences were found to contain the conserved amino acids associated with certain bioactivities in peptides found in piscivorous Conus species. The O2 superfamily was also highly diverse but conikot-ikot and an unassigned superfamily (MMSRMG) were more diverse than the rest of the superfamilies. In terms of gene expression levels, the understudied MEFRR paralog of the ancestral divergent M---L-LTVA superfamily was found to be the most highly expressed in the transcriptome, suggesting a novel role. Additionally, a conopeptide with high sequence similarity to A2 secretory group XII phospholipases is the first reported member of this phospholipase group in Conus and potentially represents a novel superfamily, expanding the catalog of known phospholipases present in cone snail venoms. The discovery of these putative conopeptides provides the first but early glimpse of the diversity and novelty of the peptides in the Asprella group and sets the stage for their functional characterization.
Drawbacks of mangrove rehabilitation schemes: Lessons learned from the large-scale mangrove plantations
Barnuevo, Abner; Asaeda, Takashi; Sanjaya, Kelum; Kanesaka, Yoshikazu; Fortes, Miguel (Estuarine, Coastal and Shelf Science, 2017-11-05)
Mangrove rehabilitation programs received much attention in the past decades as a response to widespread global degradation. While the documented successes and failures of mangrove rehabilitation accomplishments were varied, the objective and scheme is common, mainly focused on planting and creating monospecific plantations. This study assessed the structural development and complexity of the large-scale plantations in the central part of Philippines and compared it with the adjacent natural stand as reference. Our study showed that planted forest in both sites had lower structural complexity than the reference natural forest. Between sites, secondary succession in the monospecific plantation in Banacon Island was inhibited as reflected by low regeneration potential, whereas recruitment and colonization of non-planted species was promoted in Olango Island. Even 60 years after the forest was created in Banacon Island, it still lacked the understory of young cohorts which together comprise the regeneration potential that can supposedly add to the structural complexity. Although a potential seed source from adjacent natural forest is available, recruitment and colonization of non-planted species did not progress. MDS analysis of tree density data showed clustering of planted forest from the natural stand. The average SIMPER dissimilarity was 79.9% and the species with highest contributions were R. stylosa (74.6%), S. alba (11.1%) and A. marina (10.6%). Within the natural forest, the same species had the highest dissimilarity contribution, whereas in the planted forest, only R. stylosa contributed the highest dissimilarity. The same trend was also revealed in the MDS ordination analysis of diameter at breast height (DBH). A one-way ANOSIM permutation test of the density and DBH showed a significant difference between the planted and natural forests. Thus, as part of silviculture management intervention, the current practices of mangrove reforestation needs to be reviewed and evaluated to determine the trajectories of its conservation objectives to achieve the best outcome and functionality of the restored habitat.