Korean Ocean Research and Development Institute

About: Korean Ocean Research and Development Institute is a facility organization based out in Busan, South Korea. It is known for research contribution in the topics: Sea surface temperature & Gene. The organization has 1770 authors who have published 3032 publications receiving 50142 citations.

State of the Climate in 2013

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Inhibitory Effects of Linear Lipopeptides From a Marine Bacillus subtilis on the Wheat Blast Fungus Magnaporthe oryzae Triticum.

Abstract: Wheat blast is a devastating fungal disease caused by a filamentous fungus, Magnaporthe oryzae Triticum (MoT) pathotype, which poses a serious threat to food security of South America and South Asia. In the course of screening novel bioactive secondary metabolites, we found that some secondary metabolites from a marine Bacillus subtilis strain 109GGC020 remarkably inhibited the growth of M. oryzae Triticum in vitro at 20 μg/disk. We tested a number of natural compounds derived from microorganisms and plants and found that five recently discovered linear non-cytotoxic lipopeptides, gageopeptides A-D (1-4) and gageotetrin B (5) from the strain 109GGC020 inhibited the growth of MoT mycelia in a dose-dependent manner. Among the five compounds studied, gageotetrin B (5) displayed the highest mycelial growth inhibition of MoT followed by gageopeptide C (3), gageopeptide D (4), gageopeptide A (1), and gageopeptide B (2) with minimum inhibitory concentrations (MICs) of 1.5, 2.5, 2.5, 10.0, and 10.0 μg/disk, respectively. Application of these natural compounds has also completely blocked formation of conidia in the MoT fungal mycelia in the agar medium. Further bioassay revealed that these compounds (1-5) inhibited the germination of MoT conidia and, if germinated, induced deformation of germ tube and/or abnormal appressoria. Interestingly, application of these linear lipopeptides (1-5) significantly suppressed wheat blast disease on detached wheat leaves. This is the first report of the inhibition of mycelial growth, conidiogenesis, conidial germination, and morphological alterations in the germinated conidia and suppression of wheat blast disease by linear lipopeptides from the strain of B. subtilis. A further study is needed to evaluate the mode of action of these natural compounds for considering them as biopesticides for managing this notorious cereal killer.

Empirical ocean-color algorithms to retrieve chlorophyll- a , total suspended matter, and colored dissolved organic matter absorption coefficient in the Yellow and East China Seas

Abstract: A bio-optical dataset collected during the 1998–2007 period in the Yellow and East China Seas (YECS) was used to provide alternative empirical ocean-color algorithms in the retrieval of chlorophyll-a (Chl-a), total suspended matter (TSM), and colored dissolved organic matter (CDOM) absorption coefficients at 440 nm (ag440). Assuming that remote-sensing reflectance (Rrs) could be retrieved accurately, empirical algorithms for TChl (regionally tuned Tassan’s Chl-a algorithm) in case-1 waters (TChl2i in case-2 waters), TTSM (regionally tuned Tassan’s TSM algorithm), and Tag440 or Cag440 (regionally tuned Tassan’s or Carder’s ag440 algorithm) were able to retrieve Chl-a, TSM, and ag440 with uncertainties as high as 35, 46, and 35%, respectively. Applying the standard SeaWiFS Rrs, TChl was not viable in the eastern part of the YECS, which was associated with an inaccurate SeaWiFS Rrs retrieval because of improper atmospheric correction. TChl behaved better than other algorithms in the turbid case-2 waters, although overestimation was still observed. To retrieve more reliable Chl-a estimates with standard SeaWiFS Rrs in turbid water (a proxy for case-2 waters), we modified TChl for data with SeaWiFS normalized water-leaving radiance at 555 nm (nLw555) > 2 mW cm−2 μm−1 sr−1 (TChl2s). Finally, with standard SeaWiFS Rrs, we recommend switching algorithms from TChl2s (for case-2 waters) to MOCChl (SeaWiFS-modified NASA OC4v4 standard algorithm for case-1 waters) for retrieving Chl-a, which resulted in uncertainties as high as 49%. To retrieve TSM and ag440 using SeaWiFS Rrs, we recommend empirical algorithms for TTSM (pre-SeaWiFS-modified form) and MTag440 or MCag440 (SeaWiFS Rrs-modified forms of Tag440 or Cag440). These could retrieve with uncertainties as high as 82 and 52%, respectively.

Styrofoam Debris as a Source of Hazardous Additives for Marine Organisms

Abstract: There is growing concern over plastic debris and their fragments as a carrier for hazardous substances in marine ecosystem. The present study was conducted to provide field evidence for the transfer of plastic-associated chemicals to marine organisms. Hexabromocyclododecanes (HBCDs), brominated flame retardants, were recently detected in expanded polystyrene (styrofoam) marine debris. We hypothesized that if styrofoam debris acts as a source of the additives in the marine environment, organisms inhabiting such debris might be directly influenced by them. Here we investigated the characteristics of HBCD accumulation by mussels inhabiting styrofoam. For comparison, mussels inhabiting different substrates, such as high-density polyethylene (HDPE), metal, and rock, were also studied. The high HBCD levels up to 5160 ng/g lipid weight and the γ-HBCD dominated isomeric profiles in mussels inhabiting styrofoam strongly supports the transfer of HBCDs from styrofoam substrate to mussels. Furthermore, microsized sty...

Data-based estimates of the ocean carbon sink variability – first results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM)

Abstract: . Using measurements of the surface-ocean CO2 partial pressure (pCO2) and 14 different pCO2 mapping methods recently collated by the Surface Ocean pCO2 Mapping intercomparison (SOCOM) initiative, variations in regional and global sea–air CO2 fluxes are investigated. Though the available mapping methods use widely different approaches, we find relatively consistent estimates of regional pCO2 seasonality, in line with previous estimates. In terms of interannual variability (IAV), all mapping methods estimate the largest variations to occur in the eastern equatorial Pacific. Despite considerable spread in the detailed variations, mapping methods that fit the data more closely also tend to agree more closely with each other in regional averages. Encouragingly, this includes mapping methods belonging to complementary types – taking variability either directly from the pCO2 data or indirectly from driver data via regression. From a weighted ensemble average, we find an IAV amplitude of the global sea–air CO2 flux of 0.31 PgC yr−1 (standard deviation over 1992–2009), which is larger than simulated by biogeochemical process models. From a decadal perspective, the global ocean CO2 uptake is estimated to have gradually increased since about 2000, with little decadal change prior to that. The weighted mean net global ocean CO2 sink estimated by the SOCOM ensemble is −1.75 PgC yr−1 (1992–2009), consistent within uncertainties with estimates from ocean-interior carbon data or atmospheric oxygen trends.