scholarly journals An improved Ekman-Birge grab for sampling an undisturbed bottom sediment core sample.

1987 ◽  
Vol 48 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Haruo FUKUHARA ◽  
Mitsuru SAKAMOTO
2013 ◽  
Vol 63 (Pt_10) ◽  
pp. 3602-3608 ◽  
Author(s):  
Yasuko Yoneda ◽  
Takashi Yoshida ◽  
Hisato Yasuda ◽  
Chiaki Imada ◽  
Yoshihiko Sako

A hydrogenogenic, carboxydotrophic marine bacterium, strain KKC1T, was isolated from a sediment core sample taken from a submerged marine caldera. Cells were non-motile, Gram-stain-negative, 1.0–3.0 µm straight rods, often observed with round endospores. Strain KKC1T grew at 55–68 °C, pH 5.2–9.2 and 0.8–14 % (w/v) salinity. Optimum growth occurred at 65 °C, pH 7.0–7.5 and 2.46 % salinity with a doubling time of 3.7 h. The isolate grew chemolithotrophically, producing H2 from carbon monoxide (CO) oxidation with reduction of various electron acceptors, e.g. sulfite, thiosulfate, fumarate, ferric iron and AQDS (9,10-anthraquinone 2,6-disulfonate). KKC1T grew heterotrophically on pyruvate, lactate, fumarate, glucose, fructose and mannose with thiosulfate as an electron acceptor. When grown mixotrophically on CO and pyruvate, C16 : 0 constituted almost half of the total cellular fatty acids. The DNA G+C content was 50.6 mol%. The 16S rRNA gene sequence of KKC1T was most closely related to those of members of the genus Moorella with similarity ranging from 91 to 89 %. Based on physiological and phylogenetic novelty, we propose the isolate as a representative of a new genus and novel species with the name Calderihabitans maritimus gen. nov., sp. nov.; the type strain of the type species is KKC1T ( = DSM 26464T = NBRC 109353T).


2021 ◽  
Author(s):  
Yukihisa Sanada ◽  
Yoshimi Urabe ◽  
Toshiharu Misonou ◽  
Takehiko Shiribiki ◽  
Takahiro Nakanishi ◽  
...  

Abstract Large quantities of volatile radionuclides were released into the atmosphere and the hydrosphere following the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on March 11, 2011. Monitoring of radiocesium in sediment is important for evaluating the behavior of radiocesium in the environment and its effect on aquatic organisms. In this study, the radiocesium distribution in the surface sediment around the FDNPP was visualized as a radiocesium map using periodical survey data from a towed gamma-ray detection system. The uncertainty of the radiocesium map was evaluated via comparison with a large amount of sediment core sample data. The characteristics of the radiocesium distribution were examined considering the seafloor topography and a geological map, which were obtained via acoustic wave survey. The characteristics of the formation of 137Cs anomaly at the estuaries were analyzed using a contour map of 137Cs concentration combined with water depth. Validation of the created map showed that it was comparable with actual sediment core samples. The map generated using the towed radiation survey depicted the 137Cs concentration distribution as the position resolution of a 1 km mesh. Finally, the 137Cs concentration decreased with time in consideration of such uncertainty.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yukihisa Sanada ◽  
Yoshimi Urabe ◽  
Toshiharu Misonou ◽  
Takehiko Shiribiki ◽  
Takahiro Nakanishi ◽  
...  

AbstractLarge quantities of volatile radionuclides were released into the atmosphere and the hydrosphere following the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on March, 2011. Monitoring of radiocesium in sediment is important for evaluating the behavior of radiocesium in the environment and its effect on aquatic organisms. In this study, the radiocesium distribution in the surface sediment around the FDNPP was visualized as a radiocesium concentration map using periodical survey data from a towed gamma-ray detection system. The uncertainty of the radiocesium map was evaluated via comparison with a large amount of sediment core sample data. The characteristics of the radiocesium distribution were examined considering the seafloor topography and a geological map, which were obtained via acoustic wave survey. The characteristics of the formation of 137Cs anomaly at the estuaries were analyzed using a contour map of 137Cs concentration combined with water depth. Validation of the created map showed that it was comparable with actual sediment core samples. The map generated using the towed radiation survey depicted the 137Cs concentration distribution as the position resolution of a 1 km mesh. Finally, the 137Cs concentration decreased with time in consideration of such uncertainty.


2006 ◽  
Vol 35 (4) ◽  
pp. 807-818 ◽  
Author(s):  
Aya Sakaguchi ◽  
Masayoshi Yamamoto ◽  
Keiichi Sasaki ◽  
Kenji Kashiwaya

2017 ◽  
Vol 51 (6) ◽  
pp. 525-536
Author(s):  
Chikumbusko Chiziwa Kaonga ◽  
Kazuhiko Takeda ◽  
Hiroshi Sakugawa ◽  
Hideo Yamazaki

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