A5103063510- Coral and Marine Ecosystems Studies
- Marine and coastal ecosystems
- Microplastics and Plastic Pollution
- Marine and fisheries research
- Marine and coastal plant biology
- Marine Biology and Ecology Research
- Fish Ecology and Management Studies
- Recycling and Waste Management Techniques
- Fish biology, ecology, and behavior
- Methane Hydrates and Related Phenomena
- Aquatic Ecosystems and Phytoplankton Dynamics
- Isotope Analysis in Ecology
- Underwater Acoustics Research
- Microbial Community Ecology and Physiology
- Astronomy and Astrophysical Research
- Ultrasound and Cavitation Phenomena
- Hydrocarbon exploration and reservoir analysis
- Marine animal studies overview
- Coastal wetland ecosystem dynamics
- Ocean Acidification Effects and Responses
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Aquaculture disease management and microbiota
- Marine Sponges and Natural Products
- biodegradable polymer synthesis and properties
Japan Agency for Marine-Earth Science and Technology
2016-2025
Nihon University
2023-2025
Institute for Molecular Science
2023
Musashino Red Cross Hospital
2022
University of California, San Diego
2016-2018
Scripps Institution of Oceanography
2016-2018
Soka University
2008-2015
Meiji University
2015
Soka University of America
2006-2013
Shinshu University
2000
Abstract Microbes can decompose biodegradable plastics on land, rivers and seashore. However, it is unclear whether deep-sea microbes degrade in the extreme environmental conditions of seafloor. Here, we report microbial decomposition representative (polyhydroxyalkanoates, polyesters, polysaccharide esters) at diverse floor locations ranging depth from 757 to 5552 m. The degradation samples was evaluated terms weight loss, reduction material thickness, surface morphological changes. Poly( l...
Separating microplastics from marine and freshwater sediments is challenging, but necessary to determine their distribution, mass, ecological impacts in benthic environments. Density separation commonly used extract by using heavy salt solutions, such as zinc chloride sodium iodide. However, current devices/apparatus for density separation, including glass beakers, funnels, upside-down funnel-shaped separators with a shut-off valve, etc., possess various shortcomings terms of recovery rate,...
Extreme storms, such as tropical cyclones, are responsible for a significant portion of the plastic debris transported from land to sea yet little is known about storm response microplastics and other in offshore open waters. To investigate this, we conducted floating surveys center Sagami Bay, Japan approximately 30 km coastline, before after passage typhoon. The concentrations (number particles/km 2 ) micro- mesoplastics were two orders magnitude higher 1-day typhoon than values recorded...
Understanding microplastic (MP) behavior in oceans is crucial for reducing marine plastic pollution. However, the complex process underlying MP transportation to deep seafloor remains unknown despite sea being considered its major sink. We focused on distribution Sagami Bay (adjacent highly populated areas of Japan), plate triple junction connected through Trough, and abyssal plain immediately below Kuroshio Extension. observed highest number MPs stations, more than previously reported. The...
The Integrated Ocean Drilling Program (IODP) Expedition 331 investigated the Iheya North hydrothermal field in Okinawa Trough. Several post‐drilling underwater vehicle investigations were conducted over 2 years to identify changes fluid discharge pattern, mineral deposition, and chemistry. Drilling‐induced high‐temperature vents identified at deep holes not only near naturally occurring NBC vent (Site C0016) but also seafloor ∼450 m distal C0014), where no was observed prior drilling. A...
This paper describes a method to survey the distribution of megabenthos over multi-hectare regions seafloor. Quantitative biomass estimates are made by combining high-resolution 3D image reconstructions, used model spatial relationships between representative taxa, with lower-resolution reconstructions taken wider area in which larger predatory animals can be observed. The is applied region Iheya North field that was target scientific drilling during IODP Expedition 331 2010. An 2.5 ha...
The abyss (3500–6500 m) covers the bulk of deep ocean floor yet little is known about extent plastic debris on abyssal seafloor. Using video imagery we undertook a quantitative assessment present seafloor (5700–5800 m depth) beneath Kuroshio Extension current system in Northwest Pacific. This body water one major transit pathways for massive amounts that are entering North Pacific Ocean from Asia. Shallower sites (1400–1500 were also investigated comparison. dominant type was single-use...
There has been an increasing interest in seafloor exploitation such as mineral mining deep-sea hydrothermal fields, but the environmental impact of anthropogenic disturbance to is poorly known. In this study, effect by scientific drilling operations (IODP Expedition 331) on seabed landscape and megafaunal habitation was surveyed for over 3 years using remotely operated vehicle video observation a field, Iheya North Okinawa Trough. We focused observations from particular site (Site C0014)...
Abstract Aim To characterize the species richness, endemism and community structure of benthic macro‐/megafauna in deep‐sea chemosynthetic ecosystems around Japanese archipelago determine conservation priority for habitats. Location Twenty‐seven methane seeps from Kuril–Japan Trench, Nankai Trough, Ryukyu Trench Sagami Bay as well 15 hydrothermal vents Izu–Bonin Arc Okinawa Trough archipelago. Methods Species richness number endemic 42 were examined using distributional data 155 mollusc,...
The distribution and migration processes of microplastics (MPs) in the marine sediments have yet to be fully elucidated. To estimate contamination levels patterns, develop countermeasures, amount MPs must understood. Rapid efficient processing numerous samples is also needed detect determine MP contamination. However, whatever sample interest, analysis time consuming. This especially case for deep-sea sediments, where particle sizes are small pretreatment complex time-consuming. address need...
Analyses of past typhoons, tropical cyclones and hurricanes have suggested that global warming may lead to increasing intensities these episodic events the impacts typhoons on oceanic biogeochemistry will also be augmented. In present study, daily variations physical–chemical environment phytoplankton community succession were investigated in Sagami Bay, Japan, after four Mawar, Sinlaku, Etau Malou which occurred 2005, 2008, 2009 2010, respectively. Immediately passage respective salinity...
Climate change has the potential for intensification of typhoons, which will cause stronger effects on aquatic ecosystems in future. The effect typhoon Mawar (T0511), passing Manazuru Port located western part Sagami Bay, Japan, was investigated from August to September 2005. Immediately after passage Mawar, photosynthetically available radiation showed high values, salinity decreased dramatically and nutrient concentrations (NO2+NO3, PO4 Si(OH)4) increased. Skeletonema spp. Leptocylindrus...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 490:11-22 (2013) - DOI: https://doi.org/10.3354/meps10481 Enrichment of microbial abundance in sea-surface microlayer over a coral reef: implications for biogeochemical cycles reef ecosystems Ryota Nakajima1,*, Kenji Tsuchiya2, Nobuyuki Nakatomi2, Teruaki Yoshida3, Yuya Tada4, Fumie Konno2, Tatsuki Toda2,...
Abstract Inorganic nutrient contents of mucus released by Acropora corals and its utilization heterotrophic bacteria at several different hour intervals in the coral were investigated a reef Malaysia. The dissolved inorganic phosphate ( DIP ) concentration was 135‐fold higher than ambient seawater, probably due to P release from gut cavity. We experimentally confirmed that rapidly (within 8 h) consumed ca. 80% initial derived mucus. High may enhance bacterial production associated carbon...
Chitin is a key component of hard parts in many organisms, but the biosynthesis two distinctive chitin allomorphs, α- and β-chitin, not well understood. The accurate determination allomorphs natural biomaterials vital. Many chitin-secreting living however, produce poorly crystalline chitin. This leads to spectrums with only broad lines imprecise peak positions under conventional analytical methods such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, solid-state nuclear...
Measurements of both particulate and dissolved organic carbon (POC DOC) release by corals are important in understanding the cycle reef systems. In this study, branches Acropora formosa (Dana, 1846) were incubated for 5 hrs POC DOC into ambient water was simultaneously measured. rate (average ± SD) 8.93 1.67 mg C m −2 hr −1 while 14.98 4.26 . Consequently, majority (ca. 63%) released A. dissolves seawater.
After the adoption of Aichi Target, data accumulation and evaluation regarding biodiversity have progressed rapidly. The use ecologically biologically significant areas (EBSAs) criteria to evaluate important enables identification effective prioritized for ecosystem management. This includes strategic environmental assessment discussions aimed at establishing protected marine based on scientific data. paper reviews previous current ideas as well methods used, EBSAs. In particular, following...
Previous studies have suggested that Crown-of-Thorns starfish (COTS) larvae may be able to survive in the absence of abundant phytoplankton resources suggesting they utilize alternative food sources. Here, we tested hypothesis COTS are feed on coral-derived organic matter using labeled stable isotope tracers (13C and 15N). Our results show (coral mucus associated microorganisms) can assimilated by an important or additional resource for through periods low biomass. This could potentially...