A5057749235- Marine and coastal ecosystems
- Marine Biology and Ecology Research
- Isotope Analysis in Ecology
- Geology and Paleoclimatology Research
- Microbial Community Ecology and Physiology
- Ocean Acidification Effects and Responses
- Methane Hydrates and Related Phenomena
- Oceanographic and Atmospheric Processes
- Aquatic Ecosystems and Phytoplankton Dynamics
- Algal biology and biofuel production
- Marine and fisheries research
- Water Quality Monitoring and Analysis
- Atmospheric and Environmental Gas Dynamics
- Marine Bivalve and Aquaculture Studies
- Arctic and Russian Policy Studies
- Marine Toxins and Detection Methods
- Peatlands and Wetlands Ecology
- Coral and Marine Ecosystems Studies
- Indigenous Studies and Ecology
- Biocrusts and Microbial Ecology
- Protist diversity and phylogeny
- Analytical chemistry methods development
- Icing and De-icing Technologies
- Climate variability and models
- Winter Sports Injuries and Performance
Japan Agency for Marine-Earth Science and Technology
2014-2023
IR Dynamics (United States)
2018
Japan Science and Technology Agency
2007
Nagoya University
2003-2004
Soka University
2002
The Argo Program has been implemented and sustained for almost two decades, as a global array of about 4000 profiling floats. provides continuous observations ocean temperature salinity versus pressure, from the sea surface to 2000 dbar. successful installation its innovative data management system arose opportunistically combination great scientific need technological innovation. Through system, fundamental physical with broad societally-valuable applications, built on cost-efficient robust...
Size-dependence of chlorophyll a (Chl a) specific absorption coefficient a*(λ) for six irradiances ranging from 25 to 750 μmol m−2 s−1 was quantified species phytoplankton varying size. These included Bacillariophyceae Thalassiosira weissflogii, Chaetoceros gracilis and Coscinodiscus sp., Chlorophyceae Dunaliella tertiolecta, Prymnesiophyceae Isochrysis galbana Pleurochrysis carterae. For the irradiances, statistically significant relationships were obtained between cell volume a*(675),...
Abstract. Photosymbiosis has played a key role in the diversification of foraminifera and their carbonate production throughout geologic history. However, identification photosymbiosis extinct taxa remains challenging, even among extant species occurrence functional relevance remain poorly constrained. Here, we investigate living planktonic by measuring active chlorophyll fluorescence with fast repetition rate fluorometry. This method provides unequivocal evidence for presence photosynthetic...
Phytoplankton photosynthetic physiology can be investigated through single-turnover variable chlorophyll fluorescence (ST-ChlF) approaches, which carry unique potential to autonomously collect data at high spatial and temporal resolution. Over the past decades, significant progress has been made in development application of ST-ChlF methods aquatic ecosystems, interpretation resulting observations. At same time, however, an increasing number sensor types, sampling protocols, processing...
In order to study the mechanism of bloom formation Noctiluca scintillans, relationship between variation in abundance N. scintillans and environmental factors was examined coastal waters Sagami Bay, Japan. Hydrographic (temperature, salinity, water stability), biological (chlorophyll a concentration, zooplankton biomass) meteorological (rainfall, wind velocity, direction) were investigated from 1997 2004. For all years, started increase March reached maximum spring April May. The 2000...
We investigated the seasonal variability of phytoplankton community in western subarctic gyre (WSG) northwestern North Pacific with respect to structure (abundance, size, and taxonomic composition) photophysiological state from 2006 2012 by using chemotaxonomy program CHEMTAX, microscopy, fast‐repetition‐rate fluorometry. Chlorophyll a standing stock (∫Chl ) varied seasonally 20 52 mg m −2 increased frequently > 40 June July. Diatoms (20–35%) prymnesiophytes (13–23%) comprised major...
Recent studies have analysed valuable compilations of data for the size-scaling phytoplankton traits, but these cannot be employed directly in most large-scale modelling studies, which typically do not explicitly resolve relevant trait values. Although some recent species composition and sorting within communities, account observed flexible response such as dynamic acclimation often laboratory experiments. In order to derive a simple yet model growth that can useful wide variety ocean...
Abstract. Rising atmospheric CO2 contents have led to greater uptake by the oceans, lowering both pH due increasing hydrogen ions and CaCO3 saturation states declining carbonate ion (CO32−). Here we used previously compiled data sets new collected in 2010 2011 investigate ocean acidification of North Pacific western subarctic gyre. In winter, gyre is a source atmosphere because convective mixing deep waters rich dissolved inorganic carbon (DIC). We calculated winter mixed layer from DIC...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 353:81-88 (2008) - DOI: https://doi.org/10.3354/meps07151 In situ observation of phytoplankton productivity by an underwater profiling buoy system: use fast repetition rate fluorometry Tetsuichi Fujiki1,2,5,*, Takuji Hosaka1,2, Hideshi Kimoto3, Takashi Ishimaru4, Toshiro Saino1,2 1Hydrospheric Atmospheric...
Abstract We used carbon dioxide (CO 2 ) system data collected during 1999–2015 to investigate ocean acidification at time series sites in the western subarctic region of North Pacific Ocean. The annual mean pH station K2 decreased a rate 0.0025 ± 0.0010 year −1 mostly response oceanic uptake anthropogenic CO . Revelle factor increased rapidly (0.046 0.022 ), an indication that buffering capacity this has declined faster than other sites. In region, winter decline slower 0.0008 0.0004 This...
Several foraminifers found in warm and low-nutrient ocean surface water have photosynthetic algae as endosymbionts (photosymbiosis). To understand the trophic interactions, we studied Globigerinoides sacculifer, a spinose planktic foraminifer that has dinoflagellate endosymbiont. We controlled two nutritional factors, feeding inorganic nutrients seawater. The growth of host symbionts photophysiological parameters were monitored under four experimental conditions. results demonstrated...
Abstract Phaeodaria, which comprise one group of large, single‐celled eukaryotic zooplankton, have been largely ignored by past marine biological studies because Phaeodaria and their delicate skeletons are liable to collapse. As a result, collection quantification specimens difficult, seasonal changes phaeodarian abundance not thoroughly studied. The transport biogenic elements sinking phaeodarians has estimated for only few representative species. Sinking particles >1 mm in size swimmers...
During a subarctic North Pacific cruise in autumn 2005, we investigated the similarities and differences between phytoplankton composition Alaskan Gyre (AG) Western Subarctic (WSG) using chemotaxonomy program CHEMTAX, microscopy flow cytometry. Chlorophyll (Chl a) standing stock was almost constant (21.5‐31.4 mg m 22 ) throughout two gyres. Prymnesiophytes were consistently dominant group (21‐50% of Chl stock) both Diatoms minor component (,10%); however, abundances large diatoms...
The genetic diversity of one the most abundant species in Arctic and subarctic oceans, pelagic snail Limacina helicina, has not yet been characterized north Pacific. This different 'forma' (L. helicina forma acuta, pacifica ochotensis), but whether or morphological differences between these are caused by phenotypic plasticity differentiation remains unclear. Here, we analysed partial nucleotide sequences mitochondrial cytochrome c oxidase subunit I gene L. from western North Pacific Ocean...
Abstract. Photosymbiosis has played a key role in the diversification of foraminifera and their carbonate production through geologic history. However, identification photosymbiosis extinct taxa remains challenging even among extant species occurrence functional relevance poorly constrained. Here, we investigate living planktonic by measuring active chlorophyll fluorescence with fast repetition rate fluorometry. This method provides unequivocal evidence for presence photosynthetic capacity...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 283:29-38 (2004) - doi:10.3354/meps283029 Phosphorus limitation of primary productivity during spring-summer blooms in Sagami Bay, Japan Tetsuichi Fujiki1,*, Tatsuki Toda2, Tomohiko Kikuchi3, Hideki Aono3, Satoru Taguchi2 1Hydrospheric Atmospheric Research Center, Nagoya University, Chikusa-ku, 464-8601,...