Article
Ecology
Suzanne M. Budge, Kathryn Townsend, Susan E. Ziegler, Santosh P. Lall
Summary: The use of fatty acid (FA) isotopic analysis in understanding food web structure has potential, but it has not been widely adopted like amino acid isotopic analyses. This is likely due to a lack of reliable information on trophic fractionation of FA, especially in higher predators. To address this, the impact of dietary fat concentration on isotopic discrimination in FA was investigated using captive Atlantic pollock. The results showed that FA-specific discrimination factors can be used to evaluate diets in marine fish and serve as valuable biomarkers in fish feeding ecology.
Article
Ecology
C. A. Bost, K. Delord, Y. Cherel, C. M. Miskelly, A. Carravieri, P. Bustamante, J. P. Y. Arnould, A. Fromant
Summary: South Georgian diving petrels undertake unexpected, direct, and long-distance foraging trips to the Antarctic Polar Front to cope with high commuting costs and spatially segregate from sympatric diving petrels during breeding season.
MARINE ECOLOGY PROGRESS SERIES
(2022)
Article
Multidisciplinary Sciences
Massimiliano Drago, Marco Signaroli, Meica Valdivia, Enrique M. Gonzalez, Asuncion Borrell, Alex Aguilar, Luis Cardona
Summary: Understanding the trophic niches of marine apex predators is essential for comprehending species interactions and achieving sustainable fisheries management. The study revealed consistent resource partitioning patterns among biting marine mammals in the Atlantic Ocean, with little overlap in isotopic niches among sympatric species.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Szymon Smolinski, Come Denechaud, Gotje von Leesen, Audrey J. Geffen, Peter Gronkjaer, Jane A. Godiksen, Steven E. Campana
Summary: The isotopic composition of inorganic carbon in otoliths can be used as a tracer to study metabolic rates and ecophysiology in wild fish. The study found that there were positive correlations between carbon isotopic composition and growth within individuals and between years, but no significant correlation between carbon isotopic composition and growth between individuals. The significant decrease in delta C-13(oto) over the century was attributed to the oceanic Suess effect and admixture of isotopically light carbon from fossil fuel.
Article
Ecology
Julie L. Vecchio, Jenny L. Ostroff, Ernst B. Peebles
Summary: Understanding lifetime trophic changes and ontogenetic habitat shifts are crucial for marine fish species conservation. By analyzing carbon and nitrogen stable isotope values in fish eye lenses, researchers were able to compare the lifetime trends of two demersal mesopredators, tilefish and red grouper, in the Gulf of Mexico. Results showed strong correlations between isotopes and eye-lens diameter in tilefish, indicating little movement over a lifetime, while red grouper exhibited cross-shelf ontogenetic movements. These findings highlight the potential utility of eye-lens isotope records in studying the life histories of lesser-known species.
MARINE ECOLOGY PROGRESS SERIES
(2021)
Review
Zoology
Ana Beatriz Navarro, Marcelo Magioli, Marcelo Zacharias Moreira, Luis Fabio Silveira
Summary: Although stable isotopes have been increasingly used in ornithology since 1980 in many places, Brazil has been slow in adopting this methodology, especially when it comes to terrestrial birds. The use of stable isotopes to study bird ecology has great potential in Brazil, and Brazilian museums and other Natural History collections can provide samples to study long-term temporal dynamics in bird ecology. Considering the negative effects of human expansion over natural areas and that stable isotopes provide useful ecological information, ornithologists in Brazil should increase their use of this tool in the future.
Article
Limnology
Huaiyu Bai, Yukun Wang, Tingting Zhang, Fangqun Dai, Lingfeng Huang, Yao Sun
Summary: Fish otolith delta N-15 is a valuable source of dietary history information for marine fish, showing a significant correlation with fish white muscle tissue delta N-15. The study found that otolith delta N-15 can be used to characterize the trophic levels of marine fish effectively.
JOURNAL OF OCEANOLOGY AND LIMNOLOGY
(2022)
Article
Plant Sciences
Kenji Suetsugu, Masahide Yamato, Jun Matsubayashi, Ichiro Tayasu
Summary: This study focused on the physiological ecology of the orchid Cypripedium debile, revealing the different ways in which green and albino individuals obtain nutrition from fungi. The results showed that green individuals have a higher proportion of carbon derived from fungi, which may contribute to the emergence of albino mutants.
Article
Plant Sciences
Kenji Suetsugu, Takashi F. Haraguchi, Ichiro Tayasu
Summary: This study provides evidence that the fully mycoheterotrophic orchids Cremastra aphylla and Cremastra appendiculata obtain carbon from deadwood via saprotrophic fungi. The findings suggest that mixotrophic relationships associated with wood-decaying fungi represent a novel evolutionary pathway for full mycoheterotrophy in orchids.
Article
Ecology
Chia-Ying Ko, Satoshi Asano, Meng-Ju Lin, Tohru Ikeya, Elfritzson M. Peralta, Ellis Mika C. Trino, Yoshitoshi Uehara, Takuya Ishida, Tomoya Iwata, Ichiro Tayasu, Noboru Okuda
Summary: This study investigated the impact of rice paddy areas on freshwater ecosystems using structural equation modeling, revealing seasonal variations in benthic macroinvertebrate diversity and the indirect effects of land use on local environments and biodiversity. The results highlight the importance of considering seasonal changes and land use practices in catchment management for environmental restoration and biodiversity conservation.
Article
Environmental Sciences
Yu Umezawa, Kanae Toyoshima, Yu Saitoh, Shigenobu Takeda, Kei Tamura, Chiaki Tamaya, Akira Yamaguchi, Chikage Yoshimizu, Ichiro Tayasu, Kazuaki Kawamoto
Summary: The study showed that atmospheric deposition-derived nutrients significantly influenced nutrient concentrations in the surface ocean, especially during the warm rainy season, potentially leading to significant phytoplankton blooms.
ENVIRONMENTAL POLLUTION
(2021)
Article
Plant Sciences
Kenji Suetsugu, Takashi F. Haraguchi, Hidehito Okada, Ichiro Tayasu
Article
Geography, Physical
Prabhakaran Ramya Bala, Sarath Pullyottum Kavil, Ichiro Tayasu, Chikage Yoshimizu, Kaustubh Thirumalai, Krishnan Sajeev, Raman Sukumar
Summary: This study used stable carbon isotopes to study paleovegetation changes in peat deposits in the montane Nilgiris, showing distinct vegetation states at different locations within the same valley responding independently to disturbances and climate changes.
Article
Ecology
Tomoaki Ichie, Shuichi Igarashi, Ryo Yoshihara, Kanae Takayama, Tanaka Kenzo, Kaoru Niiyama, Nur Hajar Zamah Shari, Fujio Hyodo, Ichiro Tayasu
Summary: Growth analysis based on tree-ring chronology is difficult in aseasonal tropical rain forests, but the measurements of xylem Delta C-14 and delta C-13 can accurately reveal the changes in tree growth and water-use efficiency over the past 50 years.
METHODS IN ECOLOGY AND EVOLUTION
(2022)
Article
Ecology
Kai Nils Nitzsche, Shigeyuki Wakaki, Katsuyuki Yamashita, Ki-Cheol Shin, Yoshikazu Kato, Hiromitsu Kamauchi, Ichiro Tayasu
Summary: Recent studies have shown that stable isotopes of calcium and strontium can serve as new trophic level indicators in terrestrial vertebrates and marine teleost fishes. This study found that most macroinvertebrates in stream food webs rely on aquatic strontium sources, while some larvae obtain terrestrial strontium through plant litter. The positive correlation between delta Ca-44/40 and delta Sr-88/86 values suggests similarities in calcium and strontium sources, even though strontium is not essential.
Article
Plant Sciences
Ryuta Yagi, Ichiro Tayasu, Kenji Suetsugu
Summary: This study investigated the mycorrhizal fungi association and nutritional mode of Cheirostylis liukiuensis, a suspected partial mycoheterotrophic plant. The molecular analysis revealed that it predominantly associates with non-ectomycorrhizal Ceratobasidiaceae fungi. This study provides valuable information on the nutritional modes of green orchids.
PLANT SPECIES BIOLOGY
(2022)
Article
Marine & Freshwater Biology
Yosuke Amano, Tsuguo Otake, Hiroyuki Togashi, Toshihiro Wada, Akihide Kasai, Yoshikazu Kato, Chikage Yoshimizu, Ichiro Tayasu, Yutaka Kurita, Kotaro Shirai
Summary: The stable isotopic ratios of stone flounder were examined to evaluate the usefulness of distinguishing different nursery habitat types based on salinity conditions. The results showed that the stable isotopic ratios varied significantly among individuals from different habitat types, indicating that it can be a reliable proxy to determine the habitat type of stone flounder.
ESTUARINE COASTAL AND SHELF SCIENCE
(2022)
Article
Biochemical Research Methods
Takuya Ishida, Hiroshi Kamiya, Yoshitoshi Uehara, Toshikuni Kato, Shogo Sugahara, Shin-Ichi Onodera, Syuhei Ban, Adina Paytan, Ichiro Tayasu, Noboru Okuda
Summary: This study presents a new pretreatment method using solid-phase extraction with zirconium-loaded resin to obtain clean Ag3PO4 for phosphate oxygen isotope analysis. The method showed high recovery rates and accuracy for KH2PO4, soil extracts, and freshwater, but low recovery rate for seawater. The ZrME columns could be regenerated and reused multiple times.
RAPID COMMUNICATIONS IN MASS SPECTROMETRY
(2022)
Article
Biochemical Research Methods
Takuya Ishida, Ichiro Tayasu, Shin-ichi Onodera, Syuhei Ban, Noboru Okuda
Summary: In this study, a new method (PaS-Zir) was developed for the analysis of phosphate oxygen isotope ratio (delta 18OPO4) in oligotrophic freshwater systems. The method uses zirconium (Zr)-loaded resin (ZrIRC) to collect sufficient phosphate samples for analysis in a shorter time compared to conventional methods, and it proved to be efficient and applicable for the study of P dynamics in oligotrophic ecosystems.
RAPID COMMUNICATIONS IN MASS SPECTROMETRY
(2022)
Article
Geochemistry & Geophysics
Shiho Yabusaki, Makoto Taniguchi, Ichiro Tayasu, Tomoya Akimichi, Noboru Ohmori, Ken Gotou, Hitoshi Watanabe, Souichirou Watanabe, Syuichi Furuya
Summary: Observations conducted in Oshino Village, Japan in January and August 2017 revealed the water quality characteristics of shallow and deep groundwater and spring water. Shallow groundwater exhibited high levels of Ca-HCO3, Mg2+, and SO42- at certain sites, while deep groundwater contained Ca-HCO3, (Ca+Na)-HCO3, (Ca+Mg)-HCO3, and NaHCO3. The mixing of irrigation and paddy water with shallow groundwater was observed in August due to evaporation and fertilization. The recharge area of deep groundwater likely increased as a result of elevation, as indicated by lower delta O-18 and delta H-2 levels compared to shallow groundwater.
GEOCHEMICAL JOURNAL
(2023)
Article
Geology
Nagayoshi Katsuta, Sin-iti Sirono, Ayako Umemura, Hirokazu Kawahara, Yuma Masuki, Chikage Yoshimizu, Ichiro Tayasu, Takuma Murakami, Hidekazu Yoshida
Summary: This study investigates the formation process and mechanism of concentrically banded Fe-oxide patterns in Navajo Sandstone and Kimberley claystone, and proposes a hypothesis regarding diffusion and dissolution by acidic fluids. The study also finds that the precipitation of Fe-oxide is related to diagenetic alteration of earlier materials in the rocks.
Article
Biology
Saori Fujii, Takashi F. Haraguchi, Ichiro Tayasu
Summary: The study utilized radiocarbon and stable isotope analysis to reveal the feeding habits of soil microarthropods. Collembola were found to mainly depend on young carbon sources, with species showing higher δN-15 values tending to consume more recent photosynthate, indicating a preference for mycorrhizal food sources. The findings highlight the importance of radiocarbon analysis in clarifying animal feeding habits and defining the roles of organisms in soil food webs.