0000000000433693

AUTHOR

Kotaro Shirai

0000-0003-3922-5971

showing 7 related works from this author

Minute co-variations of Sr/Ca ratios and microstructures in the aragonitic shell of Cerastoderma edule (Bivalvia) – Are geochemical variations at the…

2017

Abstract It remains a challenging task to reconstruct water temperatures from Sr/Ca ratios of bivalve shells. Although in many aragonitic species, Sr/Ca is negatively correlated to temperature – which is expected based on abiogenic precipitation experiments, the incorporation of Sr into the shell of bivalves is strongly controlled by physiological processes and occurs away from the predicted thermodynamic equilibrium. Strontium-to-calcium ratios of aragonitic shells remain far below that of the ambient water. Moreover, Sr concentrations vary considerably among shell portions consisting of different microstructures and/or organic content. Values observed at annual growth lines and within the…

StrontiumCerastoderma edule010504 meteorology & atmospheric sciencesbiologyChemistryPrecipitation (chemistry)Shell (structure)Mineralogychemistry.chemical_elementElectron microprobe010502 geochemistry & geophysicsBivalviabiology.organism_classificationMicrostructure01 natural sciencesGeochemistry and PetrologySclerochronology0105 earth and related environmental sciencesGeochimica et Cosmochimica Acta
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Fundamental questions and applications of sclerochronology: Community-defined research priorities

2020

WOS:000582677500029; International audience; Horizon scanning is an increasingly common strategy to identify key research needs and frame future agendas in science. Here, we present the results of the first such exercise for the field of sclerochronology, thereby providing an overview of persistent and emergent research questions that should be addressed by future studies. Through online correspondence following the 5th International Sclerochronology Conference in 2019, participants submitted and rated questions that addressed either knowledge gaps or promising applications of sclerochronology. An initial list of 130 questions was compiled based on contributions of conference attendees and …

0106 biological sciencesFuture studies010504 meteorology & atmospheric sciencesEcology (disciplines)Data managementsub-04mercenaria-mercenariaClimate scienceAquatic ScienceOceanography01 natural sciencesField (computer science)metabolic carbon contributionSclerochronologySclerochronologysea-surface temperatureSociologyHorizon scanning0105 earth and related environmental sciencesgrowth-patternsbusiness.industryoxygen isotopes010604 marine biology & hydrobiologyResearch needsstable-isotopesData sciencewater bivalve shellsclimate-driven synchronyhigh-resolution sr/ca[SDU]Sciences of the Universe [physics]DISCOVERYgreat-barrier-reef[SDE.BE]Environmental Sciences/Biodiversity and Ecologybusiness
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Assessment of the mechanism of elemental incorporation into bivalve shells (Arctica islandica) based on elemental distribution at the microstructural…

2014

Abstract To address the mechanism of elemental incorporation into shells of the bivalve Arctica islandica , we performed two-dimensional elemental mapping of Sr, Mg, and S at a ∼3 μm spatial resolution using electron microprobe. These elemental distributions were precisely compared to the shell microstructure. The Sr distribution was intimately linked to the S concentration and/or shell microstructure. Sr showed a clear annual pattern with higher values at the annual growth lines and lower values in annual growth increments. The Sr and S concentrations were higher near sub-annual growth lines than in the adjacent regions, which were dominated by acicular microstructure (middle shell layer) …

AcicularbiologyShell (structure)MineralogyElectron microprobebiology.organism_classificationMicrostructureAnnual growth %chemistry.chemical_compoundCalcium carbonatechemistryGeochemistry and PetrologyElemental distributionArctica islandicaGeochimica et Cosmochimica Acta
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Interannual to decadal variability of summer sea surface temperature in the Sea of Okhotsk recorded in the shell growth history of Stimpson's hard cl…

2017

Abstract Sclerochronological and shell stable oxygen isotopic analyses were conducted on live-caught specimens of Stimpson's hard clams, Mercenaria stimpsoni , from the southern Sea of Okhotsk, off northern Hokkaido, Japan. In this region, the main growing season of this species during early ontogeny (below the age of 12 years) lasts from mid-spring to mid-fall at sea surface temperatures (SST) between approximately 10 and 22 °C. Growth cessation begins between late fall and early spring at SST, below approximately 6 °C; however, shell growth was largely limited to the summer season later in life. Counting of annual increments indicated that this species had a relatively long life span of u…

Global and Planetary Change010504 meteorology & atmospheric sciencesOntogenyMercenaria stimpsoniGrowing seasonOceanic climate010502 geochemistry & geophysicsOceanography01 natural sciencesSummer seasonSea surface temperatureOceanographySclerochronologyGeology0105 earth and related environmental sciencesChronologyGlobal and Planetary Change
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Microscale magnesium distribution in shell of the Mediterranean mussel Mytilus galloprovincialis: An example of multiple factors controlling Mg/Ca in…

2019

Abstract Since magnesium concentration (Mg/Ca) in biogenic calcite is considered to reflect water temperature during precipitation, the magnesium-to‑calcium ratio has been examined as a proxy for water temperature in paleoclimate research, although factors other than temperature may also influence Mg/Ca in biogenic calcite, thereby introducing a potential bias in the relationship between Mg/Ca and temperature observed in inorganic systems. To better understand factors controlling Mg incorporation into the calcitic shells of bivalves, the distribution of Mg in the Mediterranean mussel Mytilus galloprovincialis was studied, being compared with ambient sea surface temperature (SST), shell grow…

chemistry.chemical_classificationCalciteMediterranean mussel010504 meteorology & atmospheric sciencesbiologyMagnesiumchemistry.chemical_elementGeology010502 geochemistry & geophysicsbiology.organism_classification01 natural sciencesMytiluschemistry.chemical_compoundSea surface temperaturechemistryGeochemistry and PetrologyEnvironmental chemistryOrganic matterGrowth rateMicroscale chemistryGeology0105 earth and related environmental sciencesChemical Geology
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A review of transgenerational effects of ocean acidification on marine bivalves and their implications for sclerochronology

2020

Abstract Ocean acidification can negatively impact marine bivalves, especially their shell mineralization processes. Consequently, whether marine bivalves can rapidly acclimate and eventually adapt in an acidifying ocean is now increasingly receiving considerable attention. Projecting the fate of this vulnerable taxonomic group is also pivotal for the science of sclerochronology – the study which seeks to deduce records of past environmental changes and organismal life-history traits from various geochemical properties of periodically layered hard tissues (bivalve shells, corals, fish otoliths, etc.). In this review, we provide a concise overview of the long-term and transgenerational respo…

0106 biological sciencesPhenotypic plasticity010504 meteorology & atmospheric sciencesEcology010604 marine biology & hydrobiologyClimate changeOcean acidificationAquatic ScienceBiologyOceanography01 natural sciencesAcclimatizationIsotopes of oxygenTransgenerational epigeneticsIsotopes of carbonSclerochronology0105 earth and related environmental sciencesEstuarine, Coastal and Shelf Science
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Sclerochronological study of the gigantic inoceramids Sphenoceramus schmidti and S. sachalinensis from Hokkaido, northern Japan

2019

OceanographySclerochronologyPaleontologyEcology Evolution Behavior and SystematicsGeologyCold seepLethaia
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