bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heavy metal concentrations in feathers and metabolomic profiles in Pacific black ducks (Anas superciliosa) from Southeastern Australia
Authors: Nzabanita Damien , Shen Hao , Grist Stephen , Hampton Jordan O , Hufschmid Jasmin , Nugegoda Dayanthi 
Published: January 2025

Abstract
Heavy metals are cumulative toxicants that frequently create negative health effects for waterbirds inhibiting contaminated freshwater systems. Although levels of exposure to heavy metals have been well documented for many waterbird species, the adverse effects of exposure remain relatively poorly understood. One emerging field that allows the exploration of such effects is metabolomics. The aim of this study was to characterize metabolomic profiles in relation to long-term heavy metal exposure in a waterbird species. In 2021, wings from 44 Pacific black ducks (Anas superciliosa) were collected by recreational hunters at three sites in Victoria, southeastern Australia. The concentrations of seven heavy metals were measured in feathers and these data were quantified via inductive coupled plasma mass spectrometry and compared with a semiquantitative assessment of 21 metabolites identified in muscle tissues from the same birds via gas chromatography-mass spectrometry. Principal component analysis was conducted to test associations between metabolites, heavy metals, and sites. Mean heavy metal concentrations detected were copper (9.97 µg/g), chromium (0.73 µg/g), iron (123.24 µg/g), manganese (13.01 µg/g), mercury (0.58 µg/g), lead (0.86 µg/g), and zinc (183.95 µg/g; dry wt). No association was found between heavy metals and 17 metabolites, whereas four metabolites were negatively associated with some heavy metals: α-linolenic acid with iron, glucose with lead and manganese, lactic acid with mercury, and propanoic acid with mercury. There were few differences in the studied metabolites in ducks between the three sites. This study provides a novel approach to combining toxicological and metabolomic data for an ecologically important species from a relatively poorly studied global region.
Oxidative stress and filtration responses in Atlantic ribbed mussels (Geukensia demissa) exposed to radium-226
Authors: Donaher Sarah E , Van den Hurk Peter , Martinez Nicole E 
Published: January 2025

Abstract
Bivalves have been extensively utilized as sentinel biomonitoring species, organisms used to predict the extent and severity of environmental contamination. However, significant knowledge gaps remain regarding the operationalization and application of indicator species for radioactive contaminants in the marine environment. Dose-dependent organism responses with validated and practical measurement protocols need to be identified for use within biomonitoring frameworks. Our study explored tissue-specific oxidative stress and filtration responses in Geukensia demissa (Atlantic ribbed mussel) following static renewal exposure to a range of aqueous radium-226 (226Ra) concentrations and exposure durations. We investigated a two-tier antioxidant response system, with radical scavenging activity as the primary response and glutathione S-transferase and lipid peroxidation activities as secondary, downstream responses. A first-stage response of 226Ra exposure was observed, indicated by increased radical scavenging activity in the mantle tissues of mussels exposed to the highest treatment concentration (200 nCi/L = 200 ng/L, 73%) compared with the tissues of control and lower concentration (1, 10, and 100 nCi/L = 1, 10, and 100 ng/L) mussels (18%–44%). However, there was no clear impact for the second-stage responses. A reduction in filtration, quantified via algal removal, was also observed for mussels exposed to the highest 226Ra treatment concentration. This work represents the first investigation on the effects of a marine bivalve exposed to aqueous 226Ra. The responses of bivalves to radiological marine pollution, and the potential for cascading impacts to populations and ecosystems, is still relatively unknown but has important implications for ecological and human well-being.
Hazard assessment of oil spill response chemical herding agents to commercially valuable North Atlantic species
Authors: Asnicar Davide , Boloori Tahereh , Durante Jason , Lassen Pia , Fritt-Rasmussen Janne , de Jourdan Benjamin , Lee Kenneth 
Published: January 2025

Abstract
Herders are surface-collecting agents that can effectively reduce the surface area of oil slicks during a spill. Currently, two herding agents, Siltech OP-40 (OP-40) and ThickSlick 6535 (TS6535), are approved for use in oil spill response operations by the United States Environmental Protection Agency National Contingency Plan. These products may be deployed when there is evidence that environmental conditions are appropriate for their application and that their use will result in a net environmental benefit. Because the toxicity of these compounds is still poorly understood, toxicity of OP-40 and TS6535 was tested on four commercially relevant North Atlantic marine species: early life stages of green sea urchin (Strongylocentrotus droebachiensis), American lobster (Homarus americanus), Atlantic cod (Gadus morhua) and lumpfish (Cyclopterus lumpus). Lethal and sublethal toxicity data (LC50 and EC50) were determined at different time points. Siltech OP-40 was found to be between 4 and 78 times more toxic than TS6535. Toxicity values ranged from 1.0 (20-min EC50 in sea urchin fertilization) to 13.4 mg/L (3-hr LC50 in lumpfish) for OP-40, and from 7.6 (72-hr LC50 in 24-hour-old embryo cod) to 476.6 mg/L (24-hr EC50 in 20-day-old cod embryo) for TS6536. In terms of decision-making for oil spill response, data from this study supports their operational use, as the measured toxicity values exceeded the theoretical concentrations expected in the environment following the deployment of herding agents.
Selenium induces mercury isotope fractionation and detoxification in marine fish
Authors: Cho Moonkyoung , Lee Seunghan , Kim Kang Woong , Besnard Lucien , Jung Saebom , Lim Seung Hyeon , Li Mi-Ling , Kwon Sae Yun 
Published: January 2025

Abstract
Prey fish are vital in transferring nutrients and contaminants from lower to higher trophic levels. Although the role of selenium (Se) on mercury (Hg) detoxification has been identified in marine mammals and seabirds, the metabolic pathways of Hg-Se interaction in fish remain unknown. We used Hg stable isotopes (δ202Hg, Δ199Hg) to characterize the internal dynamics of methylmercury (MeHg) and inorganic Hg (IHg) in the presence and absence of Se in juvenile olive flounders (Paralichthys olivaceus). The fish were exposed to MeHg- (1,223 ng/g, n = 31) and IHg-amended (1,515 ng/g, n = 31) food pellets for 4 weeks (bioaccumulation phase) and switched to control or Se-amended food pellets for 10 weeks (excretion phase). During the bioaccumulation phase, the Hg isotopic composition of all fish tissues shifted toward their respective food pellets. During the excretion phase, significant negative δ202Hg shifts (0.27–0.59 ‰) were recorded in the liver of fish initially fed MeHg food pellets and then switched to Se food pellets, which is indicative of Se-induced hepatic MeHg demethylation. Fish fed IHg food pellets and then switched to control or Se food pellets exhibited similar isotopic behavior, suggesting that Se plays a minor role in IHg excretion. Both δ202Hg and Δ199Hg of the liver shifted toward IHg food pellets even during the excretion phase, which we attribute to slow intestinal IHg mobilization and redistribution to the liver. We found that the liver is the major site for MeHg demethylation in the presence of Se and that Se plays a relatively minor role in IHg excretion. Tissue-specific Hg isotope dynamics and interaction with Se should be considered in future Hg ecotoxicological assessments in fish.
Emissions of water-soluble polymers from household products to the environment: a prioritization study
Authors: Brunning Hattie , Sallach J Brett , Boxall Alistair 
Published: January 2025

Abstract
Water-soluble polymers (WSPs) are widely used in household products, including cleaning and personal care products. However, unlike insoluble plastic polymers, the environmental risks of WSPs are poorly understood. This study was performed to identify polymers in household use and characterize their emissions to the environment and key data gaps for prioritization. An inventory of polymers was developed and these were broadly grouped based on structure. Information from patents was combined with literature data to estimate down-the-drain emissions for each polymer. For the polymers with the highest emissions, predicted environmental concentrations for surface water and soil were estimated. A total of 339 individual polymers were identified and categorized into 26 groups. The polymers with the highest down-the-drain emissions were sodium laureth sulfate (1.6–3.4 g capita−1 day−1), styrene/acrylates copolymer (0.1–0.8 g capita−1 day−1), and monoethanolamine-laureth sulfate (0.4–0.8 g capita−1 day−1). An analysis of available fate and ecotoxicity data for 30 key high-emission polymers indicated that several are lacking in data. In particular, no data were found for styrene/acrylates copolymer and copolymer of polyethylene glycol/vinyl acetate, and the environmental fate of polyquaterniums and polyol ethoxylate esters has been understudied, particularly in light of their hazard potential. However, a lack of reporting of key polymer properties hinders analysis. We recommend increased transparency in reporting of polymer identities moving forward as well as experimental work determining fate, removal, and hazard of the prioritized high-emission polymers that are lacking in data.
Impact of developmental methylmercury exposure on avian embryonic development, hatchling growth, and survival
Authors: Leaphart James C , Chinn Sarah M , Beasley James C 
Published: January 2025

Abstract
Methylmercury (MeHg) is a globally ubiquitous and persistent environmental toxicant that negatively affects animal behavior, health, and reproduction. In birds, MeHg is transferred from female to egg, contaminating embryos during sensitive stages of early embryonic development and growth. This toxic exposure in the prenatal environment not only induces mortality but also possible lasting impacts on physiology, health, and survival, even once hatched. The purpose of our study was to further elucidate the negative effects of MeHg exposure during avian embryonic development and explore how such exposure can impact offspring development, growth, and survival, both in ovo and posthatch. To assess this, we experimentally dosed fertile mallard and wood duck eggs with MeHg II chloride and reared developing embryos and ducklings to various endpoints. We found that embryos not only readily accumulated MeHg throughout incubation, but they also displayed varying dose-dependent disparities in body mass and morphometrics, with control individuals being larger during early and late embryonic stages of development (p &lt; 0.05). Furthermore, hatched offspring exposed to MeHg exhibited increasingly slower growth rates between 7 to 10 and 10 to 15 days posthatch (p &lt; 0.05), and were found to have lower survival probabilities both under controlled laboratory conditions (p &lt; 0.005), and in the natural environment (p &lt; 0.05). Our findings on the detrimental effects of MeHg on avian embryos and hatchlings emphasize the need for more proactive means of environmental protection and remediation to protect vulnerable avian populations and the ecosystems they inhabit.
Development of a bioaccumulation model for selenium oxyanions and organoselenium in stream biota
Authors: de Bruyn Adrian M H , Heddle Cybele B , Ings Jennifer , Gürleyük Hakan , Brix Kevin V , Luoma Samuel N , Arnold Mariah C 
Published: January 2025

Abstract
Selenium (Se) occurs in natural surface waters as a variety of inorganic and organic chemical species, typically dominated by the oxyanions selenate and selenite. Organoselenium species, although hypothesized to be more bioavailable than oxyanions, have rarely been identified or quantified in natural waters and little is known about their fate or bioaccumulative potential. We studied spatial patterns of bioaccumulation in relation to aqueous Se speciation over 5 years at more than 100 locations near coal mine operations in southeast British Columbia, Canada. We used a sequential approach to fitting bioaccumulation model coefficients, first using sites with no detectable organic Se species (&lt; 0.01 µg L−1) to describe the bioaccumulation of selenate and selenite, then applying those relationships to the remaining sites to infer the bioavailability of detectable organoselenium species. Our analysis indicated that the methylated species methylseleninic acid was the most bioaccumulative form, followed by dimethylselenoxide. Organoselenium species were associated primarily with mine sedimentation ponds and are presumed to be products of Se metabolism by algae and bacteria. Highly bioavailable organoselenium species exported from the ponds appear to be responsible for enhanced Se bioaccumulation in biota in downstream lotic reaches, with this influence diminishing with distance from ponds as concentrations decline. Our findings indicate that managing biological productivity in mine sedimentation ponds could help manage Se risk in the receiving environment.
The effect of pH on chronic copper toxicity to Ceriodaphnia dubia within its natural pH niche
Authors: De Schamphelaere Karel A C , Baken Stijn , Cardwell Allison , Du Laing Gijs , Nys Charlotte , Stubblefield William , Viaene Karel , Weighman Kristi 
Published: January 2025

Abstract
The pH of freshwater ecosystems affects bioavailability of various metals to various organisms, including daphnids. Although it is well known that daphnid species show interclonal variation of metal sensitivity, knowledge about interclonal variation of bioavailability effects, such as the pH effect, is scarce. Here, we compared the effect of pH on chronic copper toxicity between two clones of Ceriodaphnia dubia, within its natural pH niche, which we determined to be approximately pH 6.5–8.5 based on existing experimental and biological monitoring data. Using a Bayesian modeling approach, we found that the effect of pH was not statistically significantly different between the two clones (with a credibility &gt; 95%). Overall, we found an approximately threefold decrease in chronic Cu toxicity with increasing pH between pH 6.5 and 8.5, with 7-day 20% effect concentration (EC20) values ranging between 11.0 and 30.9 µg/L dissolved Cu. We then calibrated a preliminary generalized bioavailability model (gBAM) using these data and found a pH-effect slope parameter SpH = −0.247, which is within the range of previously reported values for Daphnia magna (–0.056 to –0.361) and similar to the SpH value of −0.220 used in the “invertebrate gBAM” for bioavailability-based Cu risk assessment under the Registration, Evaluation, Authorisation and Restriction of Chemicals. The preliminary C. dubia gBAM captured the magnitude of the observed pH effect well (mean of 1.3-fold EC20 prediction error, n = 9). It was also able to accurately predict chronic Cu toxicity in natural waters reported in an independent dataset (mean of 1.4-fold prediction error, n = 6). Also, two D. magna gBAMs (for two clones) and the invertebrate gBAM showed comparable predictive capabilities. Collectively, our work highlights the importance of studying relations between pH and metal bioavailability within the species’ natural niche. It also confirms earlier findings that biological variation of pH-bioavailability relations typically does not have a large impact on predictive capacity of bioavailability models, which is important for regulatory applications.
Spatial patterns of microplastics in freshwater bivalves (Bivalvia: Unionidae and Sphaeriidae) relative to municipal wastewater effluent discharges
Authors: Robson Emily L , Kidd Karen A , Sun Evlyn K , Gillis Patricia L , Prosser Ryan S 
Published: January 2025

Abstract
Microplastics are discharged by municipal wastewater treatment plants (WWTPs); however, their uptake by filter-feeding freshwater bivalves is poorly understood. This study examined the abundance and characteristics of microplastics in wild bivalves from five locations along a 155 km stretch of the Grand River (Ontario, Canada) in 2021–2022, including upstream and downstream of three municipal WWTPs. At each site, fingernail clams (Sphaeriidae spp., n = 5 composites), freshwater mussels (Lasmigona costata, n = 10; gill, digestive gland, and hemolymph), and surface water (n = 3) were sampled at a single timepoint. Microplastics (particles &gt;38 μm to 5 mm) were isolated and visualized via stereomicroscopy, and a subset chemically analyzed using Fourier transform infrared spectroscopy. Fingernail clams contained the highest total blank corrected microparticle counts (35.5 ± 29.4 g−1 [mean ± SD]), mussel tissues ranged from 4.3 ± 4.2 mL−1 in hemolymph to 6.5 ± 8.1 g−1 in digestive gland, and water contained 5.5 ± 2.8 L−1. Fibers were the dominant morphology across all samples, most particles were between 80 μm and 2 mm in length and, of those analyzed chemically, 30.0% were a plastic polymer. At sites downstream of WWTP outfalls, elevated counts were only seen in mussel gills and not in other bivalve tissues or water compared with upstream samples. Although microplastics were found across all sites in both biotic and abiotic compartments, results suggest little impact of WWTP discharges on their uptake in downstream bivalves.
The influence of soil organic matter content on the toxicity of pesticides to the springtail Folsomia candida
Authors: van Hall Bart G , Sweeney Christopher J , Bottoms Melanie , van Gestel Cornelis A M 
Published: January 2025

Abstract
The European environmental risk assessment (ERA) of pesticides to soil invertebrates applies a correction factor (CF) of 2 to endpoints derived from toxicity tests with lipophilic pesticides (log Kow &gt; 2) to correct for differences in organic matter (OM) content between artificial soil (AS) and natural soils. Because the applicability of this CF to springtails has never been assessed, this study investigated the influence of soil OM content on the toxicity of five pesticide active substances differing in lipophilicity to the springtail Folsomia candida. Toxicity tests following Organisation for Economic Cooperation and Development guideline 232 were conducted in AS containing 10%, 5%, and 2.5% peat and a natural soil (LUFA 2.2) with 4.5% OM. For all pesticides, toxicity (median lethal and median effect concentrations [LC50s, EC50s]) differed significantly between soils and strongly negatively correlated with soil OM content in AS (r2 &gt; 0.88). Utilizing the regression equations derived from the data, LC50s and EC50s were calculated for soils with 10% and 5% OM. For EC50s, the differences in model-estimated toxicity between these soils ranged from 1.85 to 3.23, sometimes exceeding the CF of 2. To identify differences between species, data from a sister paper on the earthworm Eisenia andrei was used. Although ratios between model-estimated EC50s in soils containing 10% and 5% OM were similar between species (2.08–3.24 for earthworms), pesticide-specific toxicity–OM relationships differed in some cases. Non-lipophilic pesticides were influenced by soil OM content in a similar manner as the lipophilic pesticides, showing that the influence of soil properties on non-lipophilic pesticides may currently be overlooked. Overall, this study shows that the CF of 2 suffers from erroneous assumptions concerning lipophilicity, OM content, and toxicity. Further research is required to improve our mechanistic understanding of the relationship between toxicity and soil OM content, ultimately increasing the ecological relevance of CFs used in ERAs.
Toxicogenomic signatures of estrogen-related modes of action in the zebrafish embryo
Authors: Frelih Milena , Ayobahan Steve U , Marghany Fatma , Essfeld Fabian , Eilebrecht Sebastian 
Published: January 2025

Abstract
Endocrine disruptors represent a diverse array of chemicals known to interfere with the endocrine systems of both human and environmental organisms, adversely affecting reproduction, development, and behavior, thus raising significant health and ecological concerns. Traditional regulatory tests for endocrine activity typically involve juvenile or adult fish, which is both time-consuming and resource-intensive and necessitates substantial animal use. This study adopts a transcriptomic approach to identify toxicogenomic signatures associated with the disruption of estrogen signaling in zebrafish (Danio rerio) embryos. Utilizing a modified zebrafish embryo toxicity test based on Organisation for Economic Co-operation and Development test guideline 236, the embryos were exposed to two sublethal concentrations of estradiol, bisphenol A, and fulvestrant. Despite no significant effects on survival or hatching rate observed in treated groups compared with the controls, our study effectively pinpointed several genes, including vtg1, cyp19a1b, fam20cl, sult1st2, pck1, agxtb, hsd17b12a, ptgs2a, and ccn1, as linked to a disruption of estrogen signaling. These genes emerge as promising biomarker candidates for identifying and distinguishing estrogen-related modes of action. Additionally, this approach not only supports the detection of potential endocrine disruptors but also opens up possibilities for prioritizing substances for higher tier endocrine testing, which could substantially reduce animal testing in the future.
Microplastic accumulation in various bird species in Turkey
Authors: Tatlı Hatice Hale , Parmaksız Arif , Uztemur Adil , Altunışık Abdullah 
Published: January 2025

Abstract
Plastic pollution constitutes one of the major environmental problems of our time, and in recent years, it has emerged as a significant threat to the environment and to various organisms, including bird species. In this context, this study, which provides the first data in Türkiye, aimed to determine the level of microplastic (MP) pollution in 12 bird species (Eurasian buzzard; short-toed snake-eagle; white stork; northern long-eared owl; common barn-owl; ruddy shelduck; Eurasian eagle-owl; scarlet macaw; common pheasant; Indian peafowl; common kestrel; and gray parrot). The results indicate that MPs were detected in 50% of the specimens (n = 20), with an average of one MP/item per individual. With an average of three MPs per individual, the short-toed snake-eagle was found to be the species with the highest MP accumulation. Fibers (range: 51–534 µm) were the most common type of plastic found in the gastrointestinal tract of birds, with ethylene vinyl acetate and navy blue being the most common polymer type and color, respectively. It was also found that the abundance of MPs increased with the weight of specimens, contributing to the hypothesis that there is a correlation between the size/weight of animals and increased levels of MP accumulation. These findings highlight the impact of plastic pollution on birdlife and the need for further monitoring to assess the ecological impact of pollution.