A5042554155- Aquaculture Nutrition and Growth
- Radioactive contamination and transfer
- Oceanographic and Atmospheric Processes
- Marine and fisheries research
- Radioactive element chemistry and processing
- Nuclear and radioactivity studies
- Fish Biology and Ecology Studies
- Climate variability and models
- Radioactivity and Radon Measurements
- Fish Ecology and Management Studies
- Marine and coastal ecosystems
- Tropical and Extratropical Cyclones Research
- Aquatic life and conservation
- Reproductive biology and impacts on aquatic species
- Isotope Analysis in Ecology
- Arctic and Antarctic ice dynamics
- Ruminant Nutrition and Digestive Physiology
- Ocean Waves and Remote Sensing
- Nuclear Issues and Defense
- Geology and Paleoclimatology Research
- Underwater Acoustics Research
- Cephalopods and Marine Biology
- Meat and Animal Product Quality
- Marine animal studies overview
- Neuroendocrine regulation and behavior
SDS Biotech (Japan)
2023
Japan Fisheries Research and Education Agency
2009-2022
Shimizu (Japan)
1998-2005
Jet Propulsion Laboratory
2002
Hokkaido University
2002
Tohoku University
1986-1989
The natural reproductive ecology of freshwater eels remained a mystery even after some their offshore spawning areas were discovered approximately 100 years ago. In this study, we investigate the for first time using collections eggs, larvae and spawning-condition adults two species in shared area Pacific. Ovaries female Japanese eel giant mottled polycyclic, suggesting that can spawn more than once during season. collection eggs near West Mariana Ridge where newly hatched also caught shows...
Abstract We compared a wide range of environmental data with measures recruitment and stock production for Japanese sardine Sardinops melanostictus chub mackerel Scomber japonicus to examine factors potentially responsible fishery regimes (periods high or low productivity). Environmental fall into two groups based on principal component analyses. The first group was determined by the Pacific Decadal Oscillation Index dominated variables associated Southern Kuroshio Sverdrup transport. second...
Enormous quantities of radionuclides were released into the ocean via both atmospheric deposition and direct release as a result Fukushima Dai-ichi Nuclear Power Plant (FNPP) accident. This study discusses southward dispersion FNPP-derived radioactive cesium (Cs) in subsurface waters. The southernmost point where we found (134)Cs (1.5-6.8 Bq m(-3)) was 18 °N, 135 °E, September 2012. potential density at peaks (100-500 m) increased water column inventories (137)Cs between 0 500 m after winter...
To address various fisheries science problems around Japan, the Japan Fisheries Research and Education Agency (FRA) has developed an ocean forecast system by combining circulation model based on Regional Ocean Modeling System (ROMS) with three-dimensional variational analysis schemes. This system, which is called FRA-ROMS, a basic essential tool for systematic conduct of science. The main aim FRA-ROMS to realistically simulate mesoscale variations over Kuroshio-Oyashio region. Here, in situ...
Tropical instability waves (TIWs), with a typical wavelength of 1000 km and period 30 days, cause the equatorial front to meander result in SST variations on order 1°–2°C. Vertical soundings temperature, humidity, wind velocity were obtained board Japanese research vessel, which sailed through three fully developed from 140° 110°W along 2°N during 21–28 September 1999. A strong temperature inversion is observed throughout cruise 2°N, capping planetary boundary layer (PBL) that 1–1.5 deep....
Abstract. The horizontal distribution of radioactive cesium (Cs) derived from the Fukushima Dai-ichi nuclear power plant (FNPP) in North Pacific is still unclear due to limitation direct measurement seawater open ocean. We present result observation Cs surface collected a broad area western and central July 2011, October 2011 2012. also conducted simple particle tracking experiment estimate qualitative spatial Pacific. 134Cs was detected at 94 stations out 123 stations, 137Cs all stations....
The spatial distributions of radiocesium concentration in sea sediment to a core depth 14 cm were investigated the offshore region from Fukushima Prefecture northern part Ibaraki February and July 2012, at resolution 5 min latitude longitude. concentrations area south Dai-ichi Nuclear Power Plant (FDNPP) generally higher than those north it. In southern area, band especially high with width about 20 km was present shallower 100 m, narrow minimal found along 200-m isobaths. more half all...
Shipboard radiosonde surveys were conducted during the 2003‐04 winter east of Japan to study atmospheric boundary layer (ABL) structure over Kuroshio Extension. ABL displayed large variations in vertical structure, most which are attributable changes surface stability. Where atmosphere was unstable (neutral) as measured by sea‐air temperature difference, turbulent heat flux increased (decreased) and a mixed‐layer developed (undeveloped) with weakened (intensified) wind shear. A linear...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 402:233-238 (2010) - DOI: https://doi.org/10.3354/meps08448 Japanese eel Anguilla japonica do not assimilate nutrition during oceanic spawning migration: evidence from stable isotope analysis Seinen Chow1,*, Hiroaki Kurogi1, Satoshi Katayama1, Daisuke Ambe2, Makoto Okazaki2, Tomowo Watanabe2, Tadafumi...
Abstract A two‐dimensional individual‐based fish movement model coupled with bioenergetics was developed to simulate the observed migration and growth of Japanese sardine ( Sardinops melanostictus ) in western North Pacific. In model, derived from ocean–environmental data as driving force, adapted a kinesis behavior. The successfully simulated transport patterns during egg larval stages northward migrations juvenile stage 2005, 2006 2007. results showed that both temperature Kuroshio...
An estimated 3.5±0.7×10(15) Bq of (137)Cs is thought to have been discharged into the ocean following melt down at Fukushima Dai-ichi Nuclear Power Plant (F1NPP). While efforts made monitor seafloor radiation levels, sampling techniques used cannot capture continuous distribution radionuclides. In this work, we apply in situ measurement using a towed gamma ray spectrometer map on within 20 km F1NPP. The results reveal existence local anomalies, with levels an order magnitude higher than...
Abstract Strontium‐90 ( 90 Sr) was released together with radioactive cesium (Cs) from the Fukushima Dai‐ichi Nuclear Power Plant FNPP ) accident. Although total amount of Sr into marine environment estimated to be a factor 100 lower than that 137 Cs, public have been concerned about safety commercial species because tendency accumulation in bones organisms, its long physical half‐life and less information concentrations species. In this study, we investigated fishes off Japan before after...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 231:151-166 (2002) - doi:10.3354/meps231151 Occurrence of jumbo flying squid Dosidicus gigas aggregations associated with countercurrent ridge off Costa Rica Dome during 1997 El Niño and 1999 La Niña Taro Ichii1,*, Kedarnath Mahapatra2, Tomowo Watanabe3, Akihiko Yatsu4, Denzo Inagake1, Yoshihiro Okada5...
In order to clarify the surface thermal conditions during ENSO events, composite analyses of SST anomaly fields were performed over western North Pacific, and for mixed layer in Kuroshio current region at sections along 137°E line a Izu Ridge. Each winter 25 years from 1961 1985 was classified into one four categorized winters, i.e., ENSO-1 year, ENSO+1 year other winters. For example, 1982/83 event, 1983 (January through March) regarded as winter. It found that winter, well-ordered positive...
Short-time tracking (one to eight days) of the Japanese eel (Anguilla japonica) using ultrasonic transmitter was performed in tropical-subtropical area adjacent spawning and temperate off Archipelago. Of 16 eels (11 wild five farmed) used, 10 displayed clear diel vertical migration (DVM) from beginning, while other farmed tracked for 19 66 hours did not. During daytime, a significantly positive correlation between depth light intensity recorded on vessel observed eels, indicating that were...
We conducted a sequential chemical extraction experiment for radiocesium (134Cs + 137Cs) using 21 surface sediment samples and two sets of size-fractionated collected offshore Fukushima. Our results support earlier reports in this area that organic substances marine sediments have an apparently higher preference than mineral substances. Observations suggest the Fukushima same order radiocesium, primarily because existence ionic competitors seawater. The apparent material is greater partial...
We measured the radiocesium (134Cs and 137Cs) contamination of 236 greenlings (Hexagrammos otakii) off coast Fukushima Prefecture in Japan, following accident at Daiichi Nuclear Power Plant March 2011. The concentrations caught approximately 40 km south power plant were significantly higher than those 50 north plant. southern waters shallow deep waters. Meanwhile, two outlier specimens with 137Cs concentrations, 16,000 Bq/kg-wet on 1 August 2012 1,150 8 May 2013, 20 from Our calculations...
To clarify the level of contamination with radioactive cesium (radiocesium) discharged from Fukushima Dai-ichi Nuclear Power Plant (FDNPP), three fish species caught in main harbor FDNPP were subjected to γ-ray analysis. The concentration radiocesium muscle differed among individual fish, even those similar size same species, and showed little relation standard length fish. maximum (202 kBq/kg wet) was detected fat greenling samples. A comparison data outside port indicated that inside...