A5034262298- Marine and fisheries research
- Marine and coastal ecosystems
- Marine Biology and Ecology Research
- Isotope Analysis in Ecology
- Cephalopods and Marine Biology
- Oceanographic and Atmospheric Processes
- Marine Invertebrate Physiology and Ecology
- Marine Toxins and Detection Methods
- Marine animal studies overview
- Underwater Vehicles and Communication Systems
- Robotics and Sensor-Based Localization
- Marine Bivalve and Aquaculture Studies
- Microbial Community Ecology and Physiology
- Ichthyology and Marine Biology
- Geology and Paleoclimatology Research
- Coral and Marine Ecosystems Studies
- Analog and Mixed-Signal Circuit Design
- Crustacean biology and ecology
- Electromagnetic wave absorption materials
- Arctic and Antarctic ice dynamics
- Aquatic Invertebrate Ecology and Behavior
- Robotic Path Planning Algorithms
- Indoor and Outdoor Localization Technologies
- Identification and Quantification in Food
- Underwater Acoustics Research
Japan Fisheries Research and Education Agency
2019-2023
Ehime University
2016-2017
Iwate Medical University
2017
The University of Tokyo
1999-2016
Okayama University
2014-2015
Hokkaido University
2010-2014
Tokyo University of Science
1999-2004
Kyushu University
1999
While most research has focused on the legality of global industrial fishing, unregulated fishing largely escaped scrutiny. Here, we evaluate nature squid fisheries using AIS data and nighttime imagery globalized fleet light-luring vessels. We find that this fishery is extensive, 149,000 to 251,000 vessel days annually, effort increased 68% over study period 2017–2020. Most vessels are highly mobile fish in multiple regions, (86%) areas. scientists policymakers express concerns declining...
Abundance and distribution of the toxic dinoflagellate Alexandrium tamarense species complex resting cyst were investigated in eastern Bering Sea Chukchi for first time. Sediment samples (top 0–3 cm depth) collected from continental shelf (17 stations) (13 together with a long core sample 0–21 one station during 2009–2012. The cysts enumerated using primuline staining method. Species identification was carried out multiplex PCR assay plate morphology vegetative cells germinated both areas....
Abstract The occurrence of galaxiid juveniles in the sea up to 700 km from New Zealand is recorded. A total 135 fish recorded 49 samples which galaxiids occurred. Data on change length with month capture indicate that marine life involves part only one calendar year, probably 6–7 months.
Remote sensing is essential for monitoring fisheries. Optical sensors such as the day–night band (DNB) of Visible Infrared Imaging Radiometer Suite (VIIRS) have been a crucial tool detecting vessels fishing at night. It remains challenging to ensure stable detections under various conditions affected by clouds and moon. Here, we develop machine learning based algorithm generate automatic consistent vessel detection. As DNB data are large highly imbalanced, design two-step approach train our...
Mesoscale anticyclonic eddies have been observed south of the Aleutian Islands. Eddies farther east, in Gulf Alaska, are known to transport coastal water and zooplankton offshore open ocean. The impacts mesoscale formed western Islands (Aleutian eddies) on community not fully understood. In present study, we describe population structures within an eddy outside during July 2010. Based sea-level anomaly, was Attu Island (172°54′E) February 2010, it moved southeastward next 5 months. Large...
The subarctic Pacific is known to have east–west gradients in the oceanic environment and phytoplankton community. western characterized by low temperature high chlorophyll a (Chl a) while eastern region Chl a. Although there little information on differences zooplankton community between Pacific, oceanographic may markedly affect this region. aim of study clarify Zooplankton were sampled at stations along 165°E line (western from 41°30′N 49°30′N) 165°W (eastern 39°N 53°30′N) using 335 100...
The eastern Bering Sea has a vast continental shelf, which contains various endangered marine mammals and large fishery resources. Recently, high numbers of toxic A. tamarense resting cysts were found in the bottom sediment surface suggesting that blooms have recently occurred. However, little is known about presence vegetative cells Sea. This study's goals to detect occurrence on shelf find relationship between environmental factors their presence. Inter-annual field surveys conducted...
Seasonal changes in body size (prosome length: PL) and oil sac volume (OSV) of the three most numerically abundant copepods Ishikari Bay, northern Sea Japan, Paracalanus parvus (Claus, 1863), Pseudocalanus newmani Frost, 1989 Oithona similis Claus, 1866, were studied using monthly samples collected through vertical hauls a 100-μm mesh NORPAC net from March, 2001 to May, 2002. PL common for species more pronounced during cold spring. was negatively correlated with temperature, this...
Localization under water is required for an underwater mobile robot to perform the survey autonomously. There a conventional method using inertial navigation system as localization water, but it takes high costs. In this study, we propose laser odometry technique robots. Laser estimating motion by tracking speckle patterns. It can measure three dimensional positions and rotation. paper, introduce principle of odometry, construction sensor unit, confirm whether inclination optical affects on or not.
Stratified zooplankton sampling was conducted in the subarctic Pacific June 2009 at four stations along 47°N from 0 to 3,000 m depth evaluate longitudinal changes population structure and vertical distribution of dominant copepod species. At westernmost station (160°E), Eucalanus bungii Metridia pacifica dominated by early copepodid stages. In E. bungii, nauplii were abundant adult females had developed ovaries 160°E, while three east (167°E, 174°E 179°W), no collected, resting stages...
A linear-in-dB VGA is fabricated in 0.18-/spl mu/m CMOS technology. It composed of three cascaded VGAs. Each them based on a conventional and proposed gain control circuit. To avoid devices parameters temperature behaviour characteristics VGA, bias circuit adapted to The range 73dB, the error within /spl plusmn/2dB, NF 5dB are obtained at 380MHz by measurement, maximum current consumption 6 mA under single 1.8V power supply.
Pelagic Mysidacea and Decapoda have important roles in marine ecosystems. However, information on their life histories is extremely limited. This study aimed to evaluate the cycles of pelagic Oyashio region, Japan. Production four dominant species was estimated by combining body mass (DM) data abundance data. belonging 5 from genera occurred area. Their biomass ranged between 11.7-50.1 ind. m −2 1.2-7.9 g wet (WM) , respectively. Six 6 belonged Decapoda, 9.0-17.3 3.0-17.3 WM Based length...
The aim of this study is to evaluate regional and interannual changes in abundance, biomass body size the hydromedusa Aglantha digitale subarctic Pacific. A. was sampled by 0–150 m vertical tows using a 100 μm mesh-size NORPAC net at stations from 41°30'N 49°30'N along 165°E line (western Pacific) 39°00'N 53°30'N 165°W (eastern during summers 2003–2006. mean numerical abundances course west east were 32.9 (range, 0–368) 169.2 (0–768) ind. m-2, respectively, those 26.3 (0–264) 69.1 (0–418) mg...