Convolution Neural Network for the Prediction of Cochlodinium polykrikoides Bloom in the South Sea of Korea

In this study, the occurrence of Cochlodinium polykrikoides bloom was predicted based on spatial information. The South Sea of Korea (SSK), where C. polykrikoides bloom occurs every year, was divided into three concentrated areas. For each domain, the optimal model configuration was determined by designing a verification experiment with 1–3 convolutional neural network (CNN) layers and 50–300 training times. Finally, we predicted the occurrence of C. polykrikoides bloom based on 3 CNN layers and 300 training times that showed the best results. The experimental results for the three areas showed that the average pixel accuracy was 96.22%, mean accuracy was 91.55%, mean IU was 81.5%, and frequency weighted IU was 84.57%, all of which showed above 80% prediction accuracy, indicating the achievement of appropriate performance. Our results show that the occurrence of C. polykrikoides bloom can be derived from atmosphere and ocean forecast information.

Characterization of Trophic Structure of Fish Assemblages in the East and South Seas of Korea Based on C and N Stable Isotope Ratios

The aim of this study was to assess seasonal variation in the food-web structure of fish assemblages in the East (two sites) and the South (one site) Seas of Korea, and to compare the isotopic niche areas between the regions. To do this, we analyzed the community structures and the δ13C and δ15N values for fish assemblages, and their potential food sources collected during May and October 2020. There were spatial differences in the diversity and dominant species of fish assemblages between the two seas. The fish assemblages in the South Sea had relatively wide ranges of δ13C and δ15N (−22.4‰ to −15.3‰ and 7.4‰ to 13.8‰, respectively) compared to those (−22.1‰ to −18.0‰ and 9.8‰ to 13.6‰, respectively) in the East Sea. The δ13C and δ15N values of suspended particulate organic matter, zooplankton, and fish assemblages differed significantly among sites and between seasons (PERMANOVA, p < 0.05, in all cases). Moreover, isotopic niche indices were relatively higher in the South Sea compared to those in the East Sea. Such differences in food-web characteristics among sites are likely due to the specific environmental effects (especially, major currents) on the differences in the species compositions and, therefore, their trophic relationships. Overall, these results allow for a deeper understanding of the changing trophic diversity and community structure of fish assemblages resulting from climate variability.

Calculation of rainfall from satellite data in and around Bangladesh

We calculated GMS Precipitation Index (GPI, satellite rainfall) using three hourly IR data from GMS-5 over Bangladesh and adjoining areas for spatial resolution of 0.5° × 0.5°, l° × 1°, 2° × 2° and temporal scales of 1-day, 3-day and 7-day and monthly averages. There was no special difference between the spatial averaging scale of 0.5° or 1° mesh on land. The GPI contours were closely spaced in 0.5° mesh and better to comprehend the GPI fluctuation. From the monsoon month of June to July the GPI maxima and minima shift from their original (starting) location. Both the GPI maxima and minima shifted toward north. There was an increase in GPI as one moved from north to south. Sea and offshore areas received almost uniform GPI compared to land areas where rain fluctuations occurred with little horizontal distance. It was found that actual rainfall was 88% of the GPI in this study.

Tikopia Collected: Raymond Firth and the Creation of Solomon Islands Cultural Heritage, Elizabeth Bonshek (2017) Collecting in the South Sea: The Voyage of Bruni d’Entrecasteaux 1791–1794, Bronwen Douglas, Fanny Wonu Veys and Billie Lythberg (eds) (2018) Resonant Histories: Pacific Artefacts and the Voyages of HMS Royalist 1890–1893, Alison Clark with Eve Haddow and Christopher Wright (2019)

Review of: Tikopia Collected: Raymond Firth and the Creation of Solomon Islands Cultural Heritage, Elizabeth Bonshek (2017) Canon Pyon: Sean Kingston Publishing, 222 pp., ISBN 978 1 90777 439 3 (hbk), £60 Collecting in the South Sea: The Voyage of Bruni d’Entrecasteaux 1791–1794, Bronwen Douglas, Fanny Wonu Veys and Billie Lythberg (eds) (2018) Leiden: Sidestone Press, 381 pp., ISBN 978 9 08890 574 2 (pbk), €60 Resonant Histories: Pacific Artefacts and the Voyages of HMS Royalist 1890–1893, Alison Clark with Eve Haddow and Christopher Wright (2019) Leiden: Sidestone Press, 272 pp., ISBN 978 9 08890 629 9 (pbk), €55