Vertical and seasonal variations of dissolved iodine concentration in coastal seawater on the northwestern Pacific coast of central Japan

2019 ◽  
Vol 188 ◽  
pp. 103966 ◽  
Author(s):  
Yuhi Satoh ◽  
Shigeki Wada ◽  
Takeo Hama
Keyword(s):  
Seasonal Variations ◽  
Pacific Coast ◽  
Iodine Concentration ◽  
Northwestern Pacific ◽  
Central Japan ◽  
Coastal Seawater

Relationship between iodine and carbohydrate contents in the seagrass Zostera marina on the northwestern Pacific coast of central Japan

2020 ◽  
Vol 63 (3) ◽  
pp. 273-281
Author(s):  
Yuhi Satoh ◽  
Shigeki Wada ◽  
Shun’ichi Hisamatsu
Keyword(s):  
Zostera Marina ◽  
Pacific Coast ◽  
Sampling Period ◽  
Northwestern Pacific ◽  
Central Japan ◽  
Total Iodine ◽  
Seasonal Trends ◽  
Structural Carbohydrate ◽  
Carbohydrate Contents ◽  
Galactose Content

AbstractPreviously, we reported seasonal variation in iodine contents in the seagrass Zostera marina. Herein, we sought the factors controlling this variation, and investigated relationships between iodine and carbohydrate contents, using extracts and residues of seagrass samples extracted with 0.1 N HCl. In plants, carbohydrates in HCl-extracted and residual fractions are considered to represent storage and structural carbohydrates, respectively. On average, 44% and 56% of total iodine in samples was contained in the HCl-extracted and residual fractions, respectively. Both HCl-extracted and residual iodine contents showed seasonal trends similar to that of total iodine, being high in winter–spring and low in summer. Total and HCl-extracted carbohydrate contents showed reverse seasonal trends from those of iodine, whereas residual carbohydrate contents had comparable values throughout the sampling period. In the total and HCl-extracted fractions, negative correlations between iodine and carbohydrate contents were confirmed, suggesting that carbohydrates do not play important roles in iodine accumulation. Although most monosaccharide contents were not correlated with iodine contents in these two fractions, residual galactose content was positively correlated with residual iodine. We accordingly suggest that one or more specific structural carbohydrate constituents may potentially function as an iodine store in Z. marina.

scholarly journals Pliocene ostracods (Crustacea) from the Togakushi area, central Japan; palaeobiogeography of trans-Arctic taxa and Japan Sea endemic species

2008 ◽  
Vol 27 (2) ◽  
pp. 161-175 ◽  
Author(s):  
Hirokazu Ozawa ◽  
Hideaki Nagamori ◽  
Tomotaka Tanabe
Keyword(s):  
High Latitude ◽  
Endemic Species ◽  
Japan Sea ◽  
Kuroshio Current ◽  
The Arctic ◽  
Northwestern Pacific ◽  
Arctic Seas ◽  
Central Japan ◽  
The Japan Sea ◽  
Northern Atlantic

Abstract. Pliocene strata (4–3 Ma) in the Togakushi area, central Japan, yield significant ostracods, which allow investigation of the origins of high-latitude (Arctic–Atlantic) taxa and the Japan Sea endemic species, together with their post-Miocene history of extinction-speciation and migration. Three types of extinct species are found here: (1) cryophilic species in common with, or closely related to, species in Plio-Pleistocene assemblages described from the Japan Sea; (2) species closely related to, or comparable with, species that characterize Miocene Japan; and (3) species endemic to the Pliocene Japan Sea. Type (1) contains species closely related to high-latitude species known from the Arctic and northern Atlantic Oceans. Their presence suggests migration from the northwestern Pacific to the northern Atlantic through the Arctic seas since the Late Pliocene after the opening of the Bering Strait. Both Types (2) and (3) contain genera originating in the south, which show high specific diversity in regions affected by the modern warm Kuroshio Current. Ancestral ostracods of Types (2) and (3) invaded the Japan Sea from the Pacific from the Middle Miocene, and diversified to produce closely related species in the semi land-locked Japan Sea until the Early Pliocene. Two new species Aurila togakushiensis sp. nov. and Aurila shigaramiensis sp. nov. are described.

A review of the genus Platyrhina (Chondrichthys: Platyrhinidae) from the northwestern Pacific, with descriptions of two new species

Zootaxa ◽  
2011 ◽  
Vol 2738 (1) ◽  
pp. 26 ◽  
Author(s):  
YUKIO IWATSUKI ◽  
KEI MIYAMOTO ◽  
KAZUHIRO NAKAYA ◽  
JIE ZHANG
Keyword(s):  
New Species ◽  
Pacific Coast ◽  
Northwestern Pacific ◽  
Nominal Species ◽  
Undescribed Species ◽  
White Pigment ◽  
Light Yellow ◽  
The Pacific ◽  
Two New Species ◽  
Pacific Species

The genus Platyrhina from the northwestern Pacific was reviewed, including a redescription and neotype proposal for Platyrhina sinensis (Bloch and Schneider 1801), and the description of two new species. Platyrhina limboonkengi Tang 1933 is relegated to the synonymy of P. sinensis, both species having two rows of hooked thorns on the mid-dorsum of the tail. Specimens previously widely identified as P. sinensis, but characterized by one row of such hooked thorns, represented an undescribed species, herein named Platyrhina tangi Iwatsuki, Zhang and Nakaya sp. nov. Platyrhina hyugaensis Iwatsuki, Miyamoto and Nakaya sp. nov., known from specimens limited primarily to the Hyuga Nada Sea, off Miyazaki, the Pacific coast of southern Japan, is similar to P. tangi in having one row of hooked thorns on the mid-dorsum of the trunk and tail, but differs in having larger hooked thorns, not encircled by light yellow or white pigment on the orbital, nape and scapular regions, and a pair of hooked thorns (absent in P. tangi) anteriorly on the scapular region. Nominal species are discussed and key to northwestern Pacific species of Platyrhina is provided.

Marine reservoir correction for the Pacific coast of central Japan using 14C ages of marine mollusks uplifted during historical earthquakes

2007 ◽  
Vol 67 (2) ◽  
pp. 286-291 ◽  
Author(s):  
Masanobu Shishikura ◽  
Tomoo Echigo ◽  
Heitaro Kaneda
Keyword(s):  
Radiocarbon Dating ◽  
Pacific Coast ◽  
Historical Earthquakes ◽  
The Sea Of Japan ◽  
Central Japan ◽  
South Central ◽  
Kanto Earthquake ◽  
The Pacific ◽  
Tectonically Active ◽  
Mollusk Assemblages

AbstractIn this study we utilize marine shell samples from two levels of historically uplifted sessile mollusk assemblages and raised wave-cut benches to evaluate the marine reservoir correction (ΔR) for the Pacific coast of central Japan. Elevation measurements of the uplifted marine shells indicate that the lower assemblage emerged during the 1923 Taisho Kanto earthquake (M7.9), whereas uplift of the upper assemblage is most likely but less confidently ascribed to the 1703 Genroku Kanto earthquake (M8.2). Radiocarbon dating of carefully selected samples from the upper and lower assemblages yielded very similar ΔR values of 82 ± 33 and 77 ± 32 yr, respectively. We regard the former ΔR value as a representative and more reliable value given the uncertainty in correlation of the upper assemblage with the 1703 earthquake. This result is consistent with previously reported ΔR values for the Pacific coast of south-central Japan and areas around the Sea of Japan that are influenced by warm ocean currents. Radiocarbon dating of coseismically uplifted shells can aid in estimating marine reservoir ages in the tectonically active Japan Islands.

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