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National Committee on Marine Sciences (NCMS)

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Author: search.filters.author.Valino, Darryl Anthony

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    Genus and size-specific susceptibility of soft corals to 2020 bleaching event in the Philippines
    Baran, Christine; Luciano, Rhea Mae A.; Segumalian, Christine; Valino, Darryl Anthony; Baria-Rodriguez, Maria Vanessa (Taylor & Francis, 2023-05-08)
    Soft corals are zooxanthellate sessile animals supporting various organisms in coral reefs. However, their populations are threatened by the impacts of ocean warming. Under thermal stress conditions, soft corals may experience mild to severe bleaching which may lead to death. Understanding soft coral bleaching responses highlights the importance in predicting how populations and diversity may be affected by changing climate scenarios. In this study, we examined the bleaching responses of the three dominant soft coral genera (Lobophytum, n = 1318; Sarcophyton, n = 116; Sinularia, n = 639 colonies) in the Bolinao-Anda Reef Complex (BARC), Pangasinan, north-western Philippines during the 2020 thermal stress event in terms of genus and colony size susceptibility, and zooxanthellae density. Degree heating week (DHW) data from 1986–2020 were obtained using remotely sensed data to determine thermal anomalies in the study sites. The maximum DHW (6.3) in 2020 occurred between July–August while bleaching surveys were done during October of the same year. The percentage of bleached portions in each colony was used to determine bleaching category: no bleaching (0%), moderately bleached (1–50%) and heavily bleached (>50%). Quantification of bleaching prevalence and susceptibility of colony sizes were determined by colony count and mean diameter measurements taken from quadrat photographs in October 2020. Haphazard tissue collection (∼3 cm) in each colony of three soft coral genera per bleaching category was done to quantify zooxanthellae density. Results showed that Lobophytum colonies had the lowest bleaching prevalence (41%), followed by Sinularia (66%) and Sarcophyton (78%). All colony size classes of the three genera were susceptible to bleaching. However, smaller colonies of Lobophytum (<15 cm), Sarcophyton (<5 cm) and Sinularia (<5 cm) showed less susceptibility than large colonies. Zooxanthellae density was significantly reduced in moderately and heavily bleached colonies. The results of this study highlight that bleaching susceptibility is genus specific, with Sarcophyton and Sinularia being more susceptible to bleaching than Lobophytum. Smaller colonies seemed to be less susceptible to bleaching than large-sized soft corals suggesting a differential thermal stress response. Spatial variations in bleaching prevalence were also found among reef sites with varying environmental conditions and thermal stress histories. This work provided initial observations on how bleaching affects soft corals. Further studies on soft coral community recovery are recommended to fully understand how these organisms perform after thermal stress events.
    We acknowledge the Bolinao Marine Laboratory of the University of the Philippines for logistics and fieldwork assistance. Thanks to Kevin Yatco and Socorro Rodrigo for providing technical assistance in obtaining remotely sensed temperature data. Thank to Kevin Yatco and Socorro Rodrigo, and Kevin Labrador for providing technical assistance in obtaining remotely sensed temperature data and assistance in statistical analysis, respectively.
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    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.
    Development of the ARHEA was funded by AIS (Archipelagic Island State) Grant 2020–2021. This research is a collaboration between MEAL UNPAD, MOCEAN, and PT Robomarine Indonesia. We would like to thank the KOMITMEN Research Group. Arnisa, Sarah, Adli Attamimi, and Jaya Kelvin had been tremendously helpful in ofering scientifc and outreach guidance throughout the project.