A5023538121- Marine animal studies overview
- Turtle Biology and Conservation
- Ichthyology and Marine Biology
- Arctic and Antarctic ice dynamics
- Aerospace Engineering and Energy Systems
- Underwater Acoustics Research
- Amphibian and Reptile Biology
- Physiological and biochemical adaptations
- Avian ecology and behavior
- Animal Vocal Communication and Behavior
- Fish Ecology and Management Studies
- Climate variability and models
- Animal Behavior and Reproduction
- Fish biology, ecology, and behavior
- Ocean Waves and Remote Sensing
- Cryospheric studies and observations
- Marine Biology and Environmental Chemistry
- Ecology and biodiversity studies
- Microplastics and Plastic Pollution
- Isotope Analysis in Ecology
- Tropical and Extratropical Cyclones Research
- Oceanographic and Atmospheric Processes
- Meteorological Phenomena and Simulations
Meijo University
2022-2025
The University of Tokyo
2010-2022
University of St Andrews
2015-2019
Abstract Ingestion of artificial debris is considered as a significant stress for wildlife including sea turtles. To investigate how turtles react to under natural conditions, we deployed animal-borne video cameras on loggerhead and green in addition feces gut contents analyses from 2007 2015. Frequency occurrences collected were 35.7% (10/28) 84.6% (11/13), respectively. Artificial appeared all (25/25) (10/10), ingested more (feces; 15.8 ± 33.4 g, gut; 39.8 51.2 g) than 1.6 3.7 9.7 15.0 g)....
Although northern bottlenose whales were the most heavily hunted beaked whale, we have little information about this species in its remote habitat of North Atlantic Ocean. Underwater anthropogenic noise and disruption their natural may be major threats, given sensitivity other to such disturbance. We attached dataloggers 13 compared sounds movements those one individual exposed escalating levels 1–2 kHz upsweep naval sonar signals. At a received sound pressure level (SPL) 98 dB re 1 μPa,...
1. Breath-hold divers are widely assumed to descend and ascend at the speed that minimizes energy expenditure per distance travelled (the cost of transport (COT)) maximize foraging duration depth. However, measuring COT with captive animals is difficult, empirical support for this hypothesis sparse. 2. We examined scaling relationship swim in free-ranging diving birds, mammals turtles (37 species; mass range, 0·5–90 000 kg) phylogenetically informed statistical methods derived theoretical...
Identifying characteristics of foraging activity is fundamental to understanding an animals' lifestyle and ecology. Despite its importance, monitoring the activities marine animals difficult because direct observation rarely possible. In this study, we use animal-borne imaging system three-dimensional data logger simultaneously observe behaviour large juvenile adult sized loggerhead turtles (Caretta caretta) in their natural environment. Video recordings showed that foraged on gelatinous...
Impact assessments for sonar operations typically use received sound levels to predict behavioural disturbance in marine mammals. However, there are indications that cetaceans may learn associate exposures from distant sources with lower perceived risk. To investigate the roles of source distance and level an area without frequent activity, we conducted multi-scale controlled exposure experiments ( n = 3) 12 northern bottlenose whales near Jan Mayen, Norway. Animals were tagged...
Monitoring the body condition of free-ranging marine mammals at different life-history stages is essential to understand their ecology as they must accumulate sufficient energy reserves for survival and reproduction. However, assessing in challenging. We cross-validated two independent approaches estimate humpback whales ( Megaptera novaeangliae ) feeding grounds Canada Norway: animal-borne tags n = 59) aerial photogrammetry 55). Whales that had a large length-standardized projected area...
Summary Ontogenetic studies of vertebrate feeding performance can help address questions relevant to foraging ecology. Feeding morphology and either limit access food resources or open up new trophic niches in both aquatic terrestrial systems. Loggerhead sea turtles are long-lived vertebrates with complex life histories that marked by an ontogenetic shift from oceanic habitat a coastal neritic habitat, transition soft prey hard, benthic prey. Although considered durophagous strong biters,...
Over the past decade, measurements from climate-oriented ocean observing system have been key to advancing understanding of extreme weather events that originate and intensify over ocean, such as tropical cyclones (TCs) extratropical bomb (ECs). In order foster further advancements predict better understand these events, a need for dedicated component specifically support studies forecasts TCs ECs has identified, but not yet implemented. New technologies, pilot networks, targeted deployments...
Air-breathing marine animals, including sea turtles, utilise two fundamentally different environments (i.e. surface and underwater) during migration. Many satellite telemetry studies have shown travel paths at relatively large spatio-temporal scales, discussing the orientation navigation mechanisms that guide turtles. However, as obtained by only reflect movements surface, little is known about ability underwater. In this study, to assess both underwater, fine-scale 3-D of free-ranging...
ABSTRACT: Tri-axis magnetism and acceleration data loggers have recently been used to obtaintime-series headings and, consequently, the 3-dimensional dive paths of aquatic animals. However,problems may arise in resulting calculation process with multiple parameters. In this study, thedive loggerhead turtles emperor penguins were reconstructed. For both species, appar-ently unrealistic movements found. Time-series heading showed small regularfluctuations synchronous stroking. penguins,...
ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 28:1-10 (2015) - DOI: https://doi.org/10.3354/esr00671 Summer-restricted migration of green turtles Chelonia mydas a temperate habitat northwest Pacific Ocean Takuya Fukuoka1,*, Tomoko Narazaki2, Katsufumi Sato1 1Atmosphere and Institute, The University Tokyo, Kashiwa, Chiba 277-8564, Japan 2Sea Mammal Unit, School...
Diving lung volume and tissue density, reflecting lipid store volume, are important physiological parameters which have only been estimated for a few breath-hold diving species. We outfitted 12 northern bottlenose whales with data loggers recorded depth, 3-axis acceleration speed either fly-wheel or from change of depth corrected by pitch angle. fitted measured values the in during 5s descent ascent glides to hydrodynamic model drag buoyancy forces using Bayesian estimation framework. The...
Many baleen whales undertake annual fasting and feeding cycles, resulting in substantial changes their body condition, an important factor affecting fitness. As a measure of lipid-store tissue density few deep diving marine mammals has been estimated using hydrodynamic glide model drag buoyancy forces. Here, we applied the method to shallow-diving humpback (Megaptera novaeangliae) North Atlantic Antarctic aggregations. High-resolution 3-axis acceleration, depth speed data were collected from...
Abstract Aim Quantifying the importance of habitat areas for conservation highly migratory marine species with complex life histories can be challenging. For example loggerhead turtles ( Caretta caretta ) nesting in Japan forage both oceanically and neritically after their reproductive period. Here, we aimed to quantify proportions using these two contrasting habitats (foraging dichotomy) suggest priority areas. Location North Pacific Ocean. Methods We examined occurrence foraging dichotomy...
To maximize foraging duration at depth, diving mammals are expected to use the lowest cost optimal speed during descent and ascent transit minimize of transport by achieving neutral buoyancy. Here, we outfitted 18 deep-diving long-finned pilot whales with multi-sensor data loggers found indications that their strategy is associated higher costs than those other toothed whales. Theoretical models predict proportional (basal metabolic rate/drag)1/3 therefore body mass0.05 The tagged animals...
ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 24:171-179 (2014) - DOI: https://doi.org/10.3354/esr00592 Juvenile green turtles on northern edge of their range: mtDNA evidence long-distance westward dispersals in Pacific Ocean Hideaki Nishizawa1,*, Tomoko Narazaki2,5, Takuya Fukuoka2, Katsufumi Sato2, Hamabata3, Masato Kinoshita4, Nobuaki Arai1,6 1Graduate School...
Summary Measuring the energy requirements of animals under natural conditions and determining how acquired is allocated to specific activities a central theme in ecophysiology. Turtle reproductive output fundamentally linked with their balance so detailed understanding marine turtle during different phases life cycle at sea essential for conservation. We used non‐invasive accelerometry technique investigate activity patterns expenditure ( EE ) adult green turtles Chelonia mydas) foraging...
Animals with high resting metabolic rates and low drag coefficients typically have fast optimal swim speeds in order to minimise energy costs per unit travel distance. The cruising of sea turtles (0.5-0.6 m s-1) are slower than those seabirds marine mammals (1-2 s-1). This study measured the answer two questions: (1) do at speed?; (2) what factors control speed turtles? 13 loggerhead 12 green were measured; then, 15 9 their estimated under natural conditions. (0.27-0.50 agreed predicted...
ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 24:85-93 (2014) - DOI: https://doi.org/10.3354/esr00588 Genetic composition of loggerhead turtle feeding aggregations: migration patterns in North Pacific Hideaki Nishizawa1,*, Tomoko Narazaki2,5, Takuya Fukuoka2, Katsufumi Sato2, Hamabata3, Masato Kinoshita4, Nobuaki Arai1,6 1Graduate School Informatics, Kyoto...
Advances in biologging technology have enabled 3D dead-reckoning reconstruction of marine animal movements at spatiotemporal scales meters and seconds. Examining high-resolution sharks (Galeocerdo cuvier, N = 4; Rhincodon typus, 1), sea turtles (Chelonia mydas, 3), penguins (Aptenodytes patagonicus, 6), mammals (Arctocephalus gazella, Ziphius cavirostris, we report the discovery circling events where animals consecutively circled more than twice relatively constant angular speeds. Similar...