Article
Environmental Sciences
M. F. Bezerra, J. A. Seminoff, G. E. Lemons, D. G. Slotton, K. Watanabe, C. T. Lai
Summary: Aquatic pollution, specifically mercury contamination, is found to be widespread and strongly associated with diet and local contamination background in batoid species, exceeding EPA water quality standards. By using multiple biogeochemical tracers, researchers were able to uncover trophic interactions and mercury accumulation among batoid populations.
ENVIRONMENTAL RESEARCH
(2021)
Review
Ecology
Ryan B. B. Stephens, Oliver N. N. Shipley, Remington J. J. Moll
Summary: Accurate trophic discrimination factors (TDF) are necessary for robustly quantifying dietary resource use and trophic position using stable isotopes. Previous studies suggested TDF values of around 1.0 for & UDelta;C-13 and 3.4 for & UDelta;N-15, but recent research indicates that these values may be more nuanced. The relative importance of different factors, such as taxa, tissues, trophic level, and diets, is still unclear.
FUNCTIONAL ECOLOGY
(2023)
Article
Ecology
Alexandra L. Bijak, Laura K. Reynolds, Ashley R. Smyth
Summary: This study examined the influence of historical and contemporary seagrass variables on sediment organic carbon storage. The results showed that historical seagrass cover, variability in cover, and species diversity were better predictors of storage than environmental variables.
Article
Environmental Sciences
Tatiparthi Srinivas, Soniya Sukumaran, K. Ramesh Babu
Summary: Stable isotopic methods are used to study food webs and quantify carbon sources in animal diets. This study focused on four abundant amphipod species in the Vashishti estuary and found that seasonal variations significantly affected isotopic values of organic matter, but not of individual amphipod species. The differences in isotopic values between amphipod species indicated species-specific diets, and the mixing model showed discrepancies in seasonal food preferences. The trophic level values of all amphipod species varied seasonally, with lower values after the monsoon, possibly due to anthropogenic nitrogen input.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Fisheries
Jean-Michel Mortillaro, Lionel Dabbadie, Andoniaina E. Raminoharisoa, Anais Paradis, Philippe Martel, Rija Andriamarolaza, Modestine Raliniaina, Olivier Mikolasek, Joel Aubin
Summary: The trophic dynamics of integrated rice and fish farming systems were studied in irrigated rice plots in Madagascar. The study assessed fish feeding behavior by analyzing stable isotopes of fish and natural feed sources. The results showed that organic fertilization can enhance natural productivity and ecological intensification of rice and fish production.
Article
Environmental Sciences
Pavanee Annasawmy, David Point, Evgeny Romanov, Nathalie Bodin
Summary: The study found variations in mercury concentrations among different organisms and regions in the southwestern Indian Ocean, with increasing Hg concentrations observed with larger body sizes. Bioaccumulation of mercury may occur in marine ecosystems.
MARINE POLLUTION BULLETIN
(2022)
Article
Marine & Freshwater Biology
Adriana Velasquez-Vacca, Jeffrey A. Seminoff, T. Todd Jones, George H. Balazs, Luis Cardona
Summary: This study analyzed stable isotope ratios in the epidermis and skeletal elements of Hawaiian green turtles to reconstruct their diet histories. The results showed that green turtles along the Kona/Kohala coast had an omnivorous diet, while those from Oahu had an herbivorous diet. The analysis also highlighted the limitations of using bone stable isotope ratios to assess green turtle diet.
Article
Engineering, Marine
Jatdilok Titioatchasai, Komwit Surachat, Ekkalak Rattanachot, Piyalap Tuntiprapas, Jaruwan Mayakun
Summary: Seagrass ecosystems are declining worldwide, and restoration efforts are being conducted to restore the ecosystem services provided by seagrasses. This study assessed a restored seagrass ecosystem using environmental DNA and found that transplanted seagrass meadows can successfully establish and provide habitat for fauna and microbes.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Biodiversity Conservation
Giulia Ferretto, Adriana Verges, Alistair G. B. Poore, Tim M. Glasby, Kingsley J. Griffin
Summary: Habitat complexity plays a critical role in shaping biotic assemblages and ecosystem processes. The decline of the late-successional seagrass Posidonia australis in some estuaries of eastern Australia, where it is now classified as an endangered ecological community, has led to reduced erosion and increased fish abundance in fragmented areas. However, areas with lower seagrass density showed higher abundance of epifauna and fish, indicating the importance of meadow characteristics in influencing ecological functions and processes.
Article
Fisheries
K. Blue Pahl, David J. Yurkowski, Sabine P. Wintner, Geremy Cliff, Matthew L. Dicken, Nigel E. Hussey
Summary: Stable-isotope analysis in liver tissue of sharks provides valuable insights into their recent feeding and movement behaviors, but careful consideration of tissue preparation techniques is necessary to avoid bias from urea and lipid concentrations. Specific C:N thresholds in liver tissue are crucial for deriving ecologically relevant isotope data, and preliminary comparisons of delta C-13 values between muscle and liver tissues can offer insights into movement and habitat behaviors of different shark species.
JOURNAL OF FISH BIOLOGY
(2021)
Article
Agronomy
F. J. Pan, L. Y. Yang, C. L. Wang, R. R. Yan, C. J. Li, Y. F. Hu, Y. Jiang, J. Cao, H. Y. Tan, X. P. Xin
Summary: The frequency of mowing significantly affects the community structure and biomass of soil nematodes in northeast China grassland. High mowing frequency reduces the abundance and biomass of soil nematodes, while moderate frequency enhances these indices.
Article
Environmental Sciences
Luu Viet Dung, Nguyen Tai Tue, Pham Van Lam, Tran Dang Quy, Vo Minh Canh, Nguyen Duc Tam, Mai Trong Nhuan
Summary: Stable isotope signatures and trace element analysis were conducted on invertebrates and fish in coastal waters of Ha Tinh Province, Central Vietnam, to study the food web structure and biomagnification or biodilution of several elements. The results showed distinct differences in isotope values between food sources and organisms at different trophic levels. Higher concentrations of certain elements were found in benthic invertebrates, crabs, and fish, with variations in accumulation and dilution observed for different elements.
ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
(2023)
Article
Ecology
Rocio Ruiz-Cooley, Tim Gerrodette, Susan J. Chivers, Kerri Danil
Summary: Analyzing the effect of stage-specific traits on species feeding habits through amino acid nitrogen stable isotopes can reveal insights into natural selection and life strategies. The study on common dolphins found no difference in feeding habits between sexes and lower variation between juveniles and adults, suggesting intraspecific feeding cooperation as an important strategy in the marine environment.
JOURNAL OF ANIMAL ECOLOGY
(2021)
Article
Environmental Sciences
Andrey N. Reshetnikov, Daniil I. Korobushkin
Summary: Isotopic signatures of carbon and nitrogen are widely used for analyzing food web structures in aquatic ecosystems. The study highlights the importance of considering the effects of different tissues, storage methods, and preservation on isotopic values in animals. Different tissues of tadpoles and postmetamorphic juveniles may vary in isotopic composition.
Article
Environmental Sciences
Changping Yang, Zaiwang Zhang, Yan Liu, Binbin Shan, Wei Yu, Hengxiang Li, Dianrong Sun
Summary: The study revealed significant heavy metal pollution in biota species from the Northern Beibu Gulf, with particularly high levels of arsenic. Crabs showed a high accumulation ability for most heavy metals, and some heavy metals exhibited potential biomagnification trends in the food webs.
MARINE POLLUTION BULLETIN
(2021)
Article
Oceanography
Jong-Ku Gal, Sun-Yong Ha, Jisoo Park, Kyung-Hoon Shin, Dongseon Kim, Nan-Young Kim, Sung-Ho Kang, Eun Jin Yang
Summary: Satellite observations and modeling data show an increase in net primary production in the Arctic Ocean due to retreating sea ice and warming, with under-ice blooms becoming more important. The role of sea-ice algae in these blooms is still unknown due to limited observations.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Environmental Sciences
Dokyun Kim, Ha-Eun Cho, Eun-Ji Won, Hye-Jin Kim, Sunggyu Lee, Kwang-Guk An, Hyo-Bang Moon, Kyung-Hoon Shin
Summary: This study investigates the trophic magnification of synthetic musk compounds and siloxanes in aquatic environments. The results show high concentrations of these compounds in water, sediments, and biota at two sites in Geum River, Republic of Korea. The trophic magnification factor (TMF) analysis based on δN-15 amino acids indicates that most of these compounds have TMF values less than 1, suggesting low accumulation in the food chain. These findings have important implications for assessing and managing the environmental fate and trophic transfer of synthetic musk compounds and siloxanes in freshwater environments.
ENVIRONMENT INTERNATIONAL
(2022)
Article
Environmental Sciences
Jong-Ku Gal, Bo Kyung Kim, Hyoung Min Joo, Chorom Shim, Boyeon Lee, Il-Nam Kim, Jinyoung Jung, Kyung-Hoon Shin, Sun-Yong Ha
Summary: The study investigated the concentrations of n-alkanes and sterols in marine particulate matter in Kongsfjorden in early spring, revealing differences in environmental factors and phytoplankton cell density between the inner and outer fjord. Certain sterols showed correlations with chlorophyll a and POC concentrations, while short-chain alkanes were found to have significantly higher concentrations in the surface layer compared to the subsurface. The distribution of lipid biomarkers in the water column provides important information for understanding the origin and transport of organic matter in the Arctic fjord.
ENVIRONMENTAL RESEARCH
(2022)
Article
Chemistry, Medicinal
Bo Kyung Kim, Mi-Ok Park, Jun-Oh Min, Sung-Ho Kang, Kyung-Hoon Shin, Eun Jin Yang, Sun-Yong Ha
Summary: This study investigated the pigment and mycosporine-like amino acid (MAA) concentrations in phytoplankton and Northen krill in sub-Arctic Kongsfjorden. The results showed that these compounds played an important role in reducing UV photodamage and the krill accumulated different compositions of MAAs, mainly from their diet of cryptophytes, and translocated them among their body parts as an adaptation for photoprotection and physiological demands.
Article
Ecology
Hee Young Yun, Thomas Larsen, Bohyung Choi, Eun-Ji Won, Kyung-Hoon Shin
Summary: Explaining food web dynamics and functioning relies on understanding feeding relations within a community. Stable isotope ratios (SIRs), including both bulk SIRs and individual amino acid (AA) SIRs, are valuable tools to express these feeding relations. This study introduces a comprehensive approach to assess carbon and nitrogen AA-SIR and reviews its versatile applications in improving our understanding of ecological processes and food web functioning.
ECOLOGY AND EVOLUTION
(2022)
Article
Microbiology
Nicholas C. Mucci, Katarina A. Jones, Mengyi Cao, Michael R. Wyatt, Shane Foye, Sarah J. Kauffman, Gregory R. Richards, Michela Taufer, Yoshito Chikaraishi, Shawn A. Steffan, Shawn R. Campagna, Heidi Goodrich-Blair
Summary: Microbial symbiosis drives the physiological processes in higher-order systems. In this study, the tripartite Xenorhabdus bacterium-Steinernema nematode-Galleria insect symbiosis was used to investigate the consumption and rebirth of organic life in a complex ecosystem. Trophic analysis revealed that the bacteria are the primary consumers of the insect, while the nematode consumes the bacteria. Metabolomics analysis showed distinct changes in biological material throughout the life cycle, including active infection, insect death, and conversion of cadaver tissues into bacterial biomass and nematode tissue. Our findings demonstrate reproducible stage-specific chemical signatures, enhancing our understanding of the metabolic processes underlying three-way symbiosis.
Article
Geosciences, Multidisciplinary
Ryuji Toue, Kazuhiko Fujita, Masashi Tsuchiya, Yoshito Chikaraishi, Yoko Sasaki, Naohiko Ohkouchi
Summary: This study investigated the trophic positions of two non-spinose species of planktonic foraminifera in the marine food web, revealing their dependence on mixed herbivorous and carnivorous diets and herbivorous diets respectively. The trophic niche separation between these two species likely contributes to their coexistence within a similar depth zone.
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2022)
Article
Environmental Sciences
Hyuntae Choi, Jeomshik Hwang, Yeongjin Ryu, Guebuem Kim, Kyung-Hoon Shin
Summary: The nitrogen isotope ratios of amino acids in sinking particles reflect the seasonal dynamics of nitrogen sources and trophic structure in the water column. Sinking particles at 2250 m contain more resuspended sediment and undergo more microbial degradation compared to samples at 1000 m.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Engineering, Environmental
Yo Han Yang, Sae Yun Kwon, Martin Tsz-Ki Tsui, Laura C. Motta, Spencer J. Washburn, Jaeseon Park, Min-Seob Kim, Kyung-Hoon Shin
Summary: By analyzing the nitrogen and mercury isotopes of eels and pike, we found that pike has consistent mercury concentration and ecological traits, making it an effective bioindicator for mercury. Eels, on the other hand, better capture site-specific mercury sources based on their mercury concentration and feeding behavior.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Limnology
Naoto F. Ishikawa, Nanako O. Ogawa, Yuchen Sun, Yoshito Chikaraishi, Yoshinori Takano, Naohiko Ohkouchi
Summary: Compound-specific isotope analysis of nitrogen in amino acids has made significant contributions to environmental sciences. Although there are different methods for determining the isotope composition, they have not been intercalibrated yet. A systematic comparison of three methods showed consistent results, validating the comparability of CSIA-AA in interdisciplinary research.
LIMNOLOGY AND OCEANOGRAPHY-METHODS
(2022)
Article
Geosciences, Multidisciplinary
Chisato Yoshikawa, Nanako O. Ogawa, Yoshito Chikaraishi, Akiko Makabe, Yohei Matsui, Yoshikazu Sasai, Masahide Wakita, Makio C. Honda, Yoshihisa Mino, Maki N. Aita, Tetsuichi Fujiki, Takuro Nunoura, Naomi Harada, Naohiko Ohkouchi
Summary: This study reveals the seasonal transition of the dominant nitrogen source for phytoplankton in the high-productivity subarctic ocean. The results show that the nitrogen source switches from nitrate to ammonium in autumn.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Jun Matsubayashi, Katsuya Kimura, Naohiko Ohkouchi, Nanako O. Ogawa, Naoto F. Ishikawa, Yoshito Chikaraishi, Yuichi Tsuda, Hiroshi Minami
Summary: Geostatistical analysis is a useful tool in tracking the migration of highly migratory marine fish. In this study, geostatistical models were used to generate isoscapes and estimate ontogenetic shifts of isotope ratios of skipjack tuna. The results showed that geostatistical analysis can provide essential information for iso-logging without compound-specific isotope analysis.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Hyuntae Choi, Bohyung Choi, Yoshito Chikaraishi, Yoshinori Takano, Haryun Kim, Kitack Lee, Dhongil Lim, Kyung-Hoon Shin
Summary: This study used compound-specific isotope analysis to investigate the variation of delta N-15 associated with microbial processes in marine sediment samples. The results showed that the decrease in amino acid concentrations in sediment was accompanied by an increase in delta N-15 values. Phenylalanine displayed a depth-dependent variation in microbial utilization, while glycine showed the highest relative molar contribution and delta N-15 increase in deep sediment. These findings provide an important basis for interpreting the delta N-15 values of amino acids in sediment.
FRONTIERS IN MARINE SCIENCE
(2022)
Review
Multidisciplinary Sciences
Naohiko Ohkouchi
Summary: Food web research is expanding rapidly with the study of natural fractional abundance of 15N in individual amino acids. This paper provides an overview of the principles of this isotope approach and reanalyzes applications, as well as extends the discussion. The method applies kinetic isotope effects to enrich 15N in specific amino acids associated with metabolic processes, which has been demonstrated through observations in natural ecosystems and laboratory experiments. The application of this approach has proven to be successful in unraveling complex food webs and addressing various issues, such as estimating food chain length, assessing nitrogen resources, tracking fish migration, and reconstructing paleodiet.
PROCEEDINGS OF THE JAPAN ACADEMY SERIES B-PHYSICAL AND BIOLOGICAL SCIENCES
(2023)
Article
Engineering, Environmental
Dokyun Kim, Eun-Ji Won, Ha-Eun Cho, Jonghyun Lee, Kyung-Hoon Shin
Summary: Although many attempts have been made to improve the accuracy of trophic magnification factor (TMF) and biomagnification factor (BMF) for assessing pollutant bioaccumulation, this study suggests an improved BMF (BMF') for mercury bioaccumulation in freshwater fish. The results show that the values of BMF' are generally higher than TMF, indicating that it is a more reliable index for risk assessment. This ecological approach provides novel insights into the behavior and trophic transfer of pollutants like mercury.