Article
Environmental Sciences
Dhanya Mohan Lal, Giri Bhavan Sreekanth, Chitra Soman, Anupam Sharma, Zeba Jaffer Abidi
Summary: The food and feeding relationships in the Ulhas River Estuary (URE) were analyzed using stable carbon and nitrogen isotopic signatures. The results showed that there were both a phytoplankton-based pelagic food chain and a detritus-based benthic food chain in URE. The ecosystem in URE exhibited a broader food web structure and higher trophic diversity, indicating the influence of anthropogenic activities on nitrogen pollution and trophic disturbance.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Environmental Sciences
Adam Sokolowski, Marlena Mordec, Magda Caban, Ida Beathe Overjordet, Ewa Wielogorska, Maria Wlodarska-Kowalczuk, Piotr Balazy, Maciej Chelchowski, Gilles Lepoint
Summary: This study investigates the behavior of pharmaceuticals in the macrobenthic food web in the Arctic coastal zone. The results show that the behavior of different pharmaceuticals varies, and trophic transfer plays a role in controlling the concentration of certain drugs in Arctic benthic communities.
SCIENCE OF THE TOTAL ENVIRONMENT
(2024)
Article
Environmental Sciences
Abdulhalim Zaryab, Hamid Reza Nassery, Kay Knoeller, Farshad Alijani, Eddy Minet
Summary: This study investigates the geochemistry and stable isotope composition of the Kabul urban aquifer, the main source of drinking water for Kabul city's inhabitants. The findings suggest that nitrate pollution in the aquifer primarily originates from sewage rather than artificial fertilizer. The results highlight the importance of improving sewage collection systems in the Kabul Plain.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Ecology
Devin L. L. Johnson, Michael T. T. Henderson, Alastair Franke, George J. F. Swan, Robbie A. A. McDonald, David L. L. Anderson, Travis L. L. Booms, Cory T. T. Williams
Summary: Stable isotope mixing models (SIMMs) are used to characterize animal diets, relying on trophic discrimination factors (TDFs) to account for food assimilation. Traditional methods for calculating TDFs are impractical and may not reflect natural variability. This study presents TDFCAM, which estimates TDFs using high-precision diet estimates from nest cameras, and evaluates its performance in wild raptor nestlings.
ECOLOGY AND EVOLUTION
(2023)
Article
Ornithology
Rebecca Mcguire, Christopher Latty, Stephen Brown, Shiloh Schulte, Sarah Hoepfner, Samuel Vassallo, Paul Smith
Summary: The study found that placing cameras near bird nests did not affect daily nest survival rates. It is suggested that the use of cameras in nest survival studies can minimize researcher disturbance, improve result accuracy, and broaden the ecological data collected.
Article
Water Resources
Filip Muhic, Pertti Ala-Aho, Kashif Noor, Jeffrey M. Welker, Bjorn Klove, Hannu Marttila
Summary: Understanding the importance of different water sources in replenishing soil water is essential for evaluating the vulnerability of sub-arctic regions to climate changes and altered precipitation patterns. This study investigated the spatiotemporal variability and seasonal origins of soil water in a sub-arctic catchment in northern Finland. Field samples were collected from May 2019 to June 2020, including soil cores and stem water of dominant tree species, and stable water isotopes were analyzed. The results showed that well-drained forested areas exhibited distinct seasonal rainfall variation and late snowmelt events, while wetter forested peatlands attenuated these signals. The connectivity to adjacent water pools controlled the soil water storage in the peatland sites. The study also revealed that snowmelt water played a significant role in replenishing and sustaining soil water storage in sub-arctic conditions, with forest soils showing a dominant meltwater signal after snowmelt. The isotopic signals of soil and stem water exhibited less offset in forested peatlands compared to other sites.
HYDROLOGICAL PROCESSES
(2023)
Article
Geosciences, Multidisciplinary
Zhimian Cao, Xinting Rao, Yang Yu, Christopher Siebert, Ed C. Hathorne, Bo Liu, Guizhi Wang, Ergang Lian, Zhibing Wang, Ruifeng Zhang, Lei Gao, Gangjian Wei, Shouye Yang, Minhan Dai, Martin Frank
Summary: The study reveals significant barium isotope fractionation at near-zero salinities in the Yangtze and Pearl River Estuary, with conservative mixing dominating delta Ba-138(DBa) distributions beyond low salinities. This provides a modern calibration for using barium isotopes as a proxy for paleosalinity and river water inputs into the ocean.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Oceanography
Hyuntae Choi, Haemin Won, Jee-Hoon Kim, Eun Jin Yang, Kyoung-Ho Cho, Youngju Lee, Sung-Ho Kang, Kyung-Hoon Shin
Summary: The trophic level and dominant diet of the Arctic copepod Calanus hyperboreus differ between the northern Chukchi Sea and the northern-East Siberian Sea due to variations in chlorophyll abundance and sea ice concentration. Differences in the proportion of diatoms consumed by C. hyperboreus in these regions may be attributed to phytoplankton composition changes caused by surface seawater stratification and inflow of sea ice meltwater as well as Bering Sea water through the Bering Strait. These results suggest that C. hyperboreus could be a valuable indicator for understanding trophic dynamics in the zooplankton food web.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Geochemistry & Geophysics
Danae Guiserix, Emmanuelle Albalat, Henriette Ueckermann, Priyanka Davechand, Linda M. Iaccheri, Grant Bybee, Shaw Badenhorst, Vincent Balter
Summary: Radiogenic strontium isotopes (Sr-87/Sr-86) are a useful tool for investigating migration and landscape use. The study shows that the Sr-88/Sr-86 ratio may reveal unknown dietary and physiological information. Furthermore, the delta Sr-88 values in tooth enamel can differentiate between plants and herbivores, but the distinction between herbivores and carnivores requires further research.
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.
Article
Engineering, Civil
Hyejung Jung, Yun S. Kim, Jisu Yoo, Bumsung Park, Jeonghoon Lee
Summary: A multi-isotopes approach combining stable nitrate isotopes (delta N-15(NO3) and delta O-18(NO3)) with stable water isotopes (delta O-18(H2O) and delta H-2(H2O)) can help identify nitrogen sources and understand transformation processes in river water systems. Seasonal variations have a significant impact on stable isotope values, leading to uncertainties in estimating the contribution of effluent to the water system.
JOURNAL OF HYDROLOGY
(2021)
Article
Biodiversity Conservation
Remi Amiraux, C. J. Mundy, Marie Pierrejean, Andrea Niemi, Kevin J. Hedges, Thomas A. Brown, Jens K. Ehn, Kyle H. Elliott, Steven H. Ferguson, Aaron T. Fisk, Grant Gilchrist, Les N. Harris, Katrin Iken, Kevin B. Jacobs, Kelsey F. Johnson, Z. A. Kuzyk, Audrey Limoges, Tracey N. Loewen, Oliver P. Love, Cory J. D. Matthews, Wesley R. Ogloff, Bruno Rosenberg, Janne E. Soreide, Cortney A. Watt, David J. Yurkowski
Summary: Climate-driven alterations in the Arctic and subarctic regions, like Hudson Bay, are causing declining sea ice, warming surface waters, and ocean acidification at alarming rates. These changes are affecting primary production patterns and will impact the entire food web. A study conducted in the Southampton Island marine ecosystem revealed the importance of both benthic and pelagic-derived prey in sustaining higher trophic level species. Additionally, the reliance of Arctic marine mammals on ice algae suggests that a decrease in ice algae productivity could have cascading effects on the benthic food web and overall Arctic ecosystem.
ECOLOGICAL INDICATORS
(2023)
Article
Environmental Sciences
Daniel Bouchard, Patrick Hohener, Didier Gori, Daniel Hunkeler, Tim Buscheck
Summary: Several types of laboratory experiments were conducted to evaluate isotope fractionation caused by phase transfer process for a selection of common environmental contaminants. Carbon and hydrogen isotope fractionation caused by vaporization of non-aqueous phase liquid (NAPL), volatilization from water, and dissolution into an organic solvent (TGDE) were investigated. The results showed significant isotope fractionation during NAPL vaporization and volatilization from water, while no significant fractionation was observed during the air-TGDE partitioning process, except for certain compounds.
Article
Environmental Sciences
Wenzhe Xu, Yongxin Dang, Siu Gin Cheung, Zhinan Zhang, Jun Sun, Ankang Teng, Paul K. S. Shin
Summary: The addition of stable isotope tracers can enhance isotopic differences of primary producers, allowing for a wider food-web resolution than using natural abundance stable isotopes alone. In a study near Halophila minor seagrass bed in Hong Kong, China, a N-15 addition experiment revealed larger dietary contributions of benthic microalgae for some infauna species compared to natural abundance stable isotopes data. This suggests the importance of combining NASIs with isotope tracer addition for a more accurate determination of dietary contributions and trophic statuses in ecosystems with similar primary producer isotope values.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Environmental Sciences
Biao Jin, Jiyun Zhang, Wenli Xu, Massimo Rolle, Jinzhong Liu, Gan Zhang
Summary: An online approach for compound specific stable isotope analysis of bromochlorinated compounds was developed in this study using gas chromatography coupled to quadrupole mass spectrometry. Stable chlorine and bromine isotope ratios were simultaneously determined based on the mass spectral data of target compounds. The method showed good precision and reproducibility under optimized instrumental conditions.
Article
Behavioral Sciences
Victor Y. Zhang, Cory T. Williams, Rupert Palme, C. Loren Buck
HORMONES AND BEHAVIOR
(2020)
Review
Cell Biology
Anusha Shankar, Cory T. Williams
Summary: The development of diurnal animal models is essential for studying seasonal affective disorder (SAD), as these models are more likely to mimic circadian disruption and show promise in replicating SAD-like behaviors. Current research suggests that diurnal rodents exhibit changes in behavior similar to SAD when exposed to short photoperiods or dim-light conditions, and these symptoms can be alleviated by exposure to bright light. Further research on the orexinergic system in diurnal models could provide insights into potential mechanisms underlying SAD.
DISEASE MODELS & MECHANISMS
(2021)
Article
Ecology
Thomas W. Glass, Greg A. Breed, Go Iwahana, Matthew C. Kynoch, Martin D. Robards, Cory T. Williams, Knut Kielland
Article
Cell Biology
C. Frare, Cory T. Williams, Kelly L. Drew
Summary: Hibernation is a unique evolutionary adaptation aimed at conserving energy. Seasonal modulation in thermoregulation, marked changes in thermoregulatory attributes, and suppression of thermogenesis characterize the hibernation season. Thyroid hormones play a key role in enhancing thermogenic capacity before hibernation, while during hibernation, thermogenesis is attenuated at the neural and hormonal levels. Further research is needed to fully understand the mechanisms of thyroid hormones in hibernation.
MOLECULAR AND CELLULAR ENDOCRINOLOGY
(2021)
Article
Behavioral Sciences
Thomas W. Glass, Greg A. Breed, Martin D. Robards, Cory T. Williams, Knut Kielland
Summary: This study investigates the trade-off between thermoregulation and predation avoidance in resting behaviors of cold-adapted wolverines. Wolverines rest in subnivean cavities or on snow surface depending on ambient temperature and solar radiation levels to balance thermal advantage and security from predators. The findings highlight the contextually dependent trade-offs important for habitat selection, energy management, and survival.
Article
Zoology
Cory T. Williams, Helen E. Chmura, Cole K. Deal, Kathryn Wilsterman
Summary: This review examines the sex differences in the timing of vertebrates' life-history from adaptive, ontogenetic, mechanistic, and phylogenetic perspectives. It emphasizes the importance of understanding the ecological and evolutionary drivers of sex differences in life-history timing, and how it connects to population resilience in the face of climate change. The early-life environment and molecular mechanisms play a significant role in sex differences, and new sequencing tools and phylogenetic analyses can provide insights into the mechanism and evolvability of sex differences. However, more attention should be given to studying sex differences in timing mechanisms and monitoring climate change responses in both sexes.
INTEGRATIVE AND COMPARATIVE BIOLOGY
(2022)
Article
Ecology
Devin L. Johnson, Michael T. Henderson, David L. Anderson, Travis L. Booms, Cory T. Williams
Summary: Intra- and inter-specific resource partitioning is a fundamental component of trophic ecology, and individual niche variation is one mechanism for achieving this partitioning. The Niche Variation Hypothesis predicts that inter-individual trait variation leads to functional trade-offs in foraging efficiency, resulting in populations composed of individual dietary specialists. Our study on an Arctic raptor guild found a high degree of niche overlap between three species, with gyrfalcons displaying a positive relationship between individual specialization and population niche width.
Article
Biology
Helen E. Chmura, Cassandra Duncan, Ben Saer, Jeanette T. Moore, Brian M. Barnes, C. Loren Buck, Helen C. Christian, Andrew S. Loudon, Cory T. Williams
Summary: This study demonstrates that arctic ground squirrels hibernating in darkness activate the thyroid hormone signaling pathway in the hypothalamus, remodel hypothalamic tanycytes, and activate the reproductive axis. Periodic arousals during hibernation may allow for transient activation of thyroid hormone signaling, cellular remodeling, and re-programming of brain circuits in preparation for the short Arctic summer.
COMMUNICATIONS BIOLOGY
(2022)
Article
Behavioral Sciences
Helen E. Chmura, Cory T. Williams
Summary: This article discusses the long-standing interest in the regulation of seasonality and emphasizes the importance of global climate change in understanding biological timekeeping. The focus is on recent advances in research on how temperature signals are integrated into seasonal hypothalamic thyroid hormone (TH) signaling, and how temperature modulates seasonal neuroendocrine pathways.
HORMONES AND BEHAVIOR
(2022)
Article
Zoology
Helen E. Chmura, Cassandra Duncan, Ben Saer, Jeanette T. Moore, Brian M. Barnes, C. Loren Buck, Andrew S. Loudon, Cory T. Williams
Summary: Animals adjust the timing of seasonal events in response to temperature changes, and this study focuses on the effects of temperature on the reproductive axis of arctic ground squirrels. It was found that temperature influenced the signaling pathway and gonadal growth differently in males and females.
INTEGRATIVE AND COMPARATIVE BIOLOGY
(2022)
Article
Zoology
Lise M. Aubry, Cory T. Williams
Summary: Seasonal variation is a crucial factor in natural selection and climate change often leads to shifts in seasonal timing. However, our understanding of the cues, mechanisms, and consequences of phenological responses is limited. Biotic interactions also play a significant role in determining the fitness outcomes of phenological shifts. To make progress in forecasting and understanding phenological responses, interdisciplinary networks focused on climate change science are necessary.
INTEGRATIVE AND COMPARATIVE BIOLOGY
(2022)
Article
Ecology
Devin L. L. Johnson, Michael T. T. Henderson, Alastair Franke, George J. F. Swan, Robbie A. A. McDonald, David L. L. Anderson, Travis L. L. Booms, Cory T. T. Williams
Summary: Stable isotope mixing models (SIMMs) are used to characterize animal diets, relying on trophic discrimination factors (TDFs) to account for food assimilation. Traditional methods for calculating TDFs are impractical and may not reflect natural variability. This study presents TDFCAM, which estimates TDFs using high-precision diet estimates from nest cameras, and evaluates its performance in wild raptor nestlings.
ECOLOGY AND EVOLUTION
(2023)