Ecological Implications Research Articles

Dose-specific biochemical and erythrocytic morpho-pathological profiling of anthracene (Polycyclic Aromatic Hydrocarbon) in an air-breathing teleost Anabas testudineus (Bloch) for establishing biomarkers

This study investigates the impact of anthracene, PAH, on the bioenzymological activity in the tissues of Anabas testudineus, commonly known as the Climbing Perch. The research was grounded in the understanding that PAHs, such as anthracene, pose significant risks to aquatic life, necessitating detailed analysis of their effects on fish physiology. The experiment employed two anthracene concentrations, T1 (0.0075 mg/L) and T2 (0.015 mg/L), representing 25 % and 50 % of the LC50, respectively, over exposure periods of 1, 5, 10, 15, and 21 days. Throughout the study, water samples were analyzed for physicochemical parameters to ensure consistent conditions. Post-exposure, fish were humanely euthanized, and their tissues (stomach, intestine, liver, and kidney) were harvested for a dose-specific bioenzymological assessment, focusing on glucose (GLU), protein (PRO), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and triglycerides (Trig). Analyzing these enzymological factors in fish tissues emerged as a pivotal method for pinpointing the bioindicators that mirror the fish's physiological state, particularly responsiveness under the contamination of PAHs, with a specific focus on anthracene. Additionally, the study delved into detecting apoptosis (programmed cell death), erythrocytic anomalies, and alterations in bioenzymological aspects within A. testudineus tissues. These observed changes demonstrated both the exposure-specific and dose-specific characteristics of anthracene. This research provides novel insights into the bioenzymatic systems of Anabas testudineus (Bloch), commonly known as the climbing perch, respond to PAHs, with a special emphasize on anthracene exposure. By elucidating these bioenzymological responses, the study underscores the importance of monitoring and managing PAH levels in aquatic environments and it attributes to SDG 14, which aims to life below water. Such measures are crucial to safeguard the health and well-being of aquatic species like A. testudineus, highlighting the broader ecological implications of PAH pollution.

Impact of run-of-river damming on increasing phytoplankton biomass and species shift in a large Amazonian river

Run-of-river (ROR) dams, often perceived as having minimal environmental impact, can induce significant hydrodynamic changes that alter aquatic ecosystems. We investigated the impacts of an ROR dam on the Madeira River, the largest Amazon tributary, focusing on phytoplankton communities, their ecological implications, and related environmental factors. Our study examined changes in biomass and environmental factors (using General Linear Mixed Models - GLMM), species composition (using PERMANOVA) before and after damming, in both the main channel and tributaries (N = 549 samples). We also identified indicator species associated with different damming phases and regions through an indicator value analysis. The results showed that, following dam construction, the phytoplankton community changed in both the main channel and tributaries, with a shift from lotic diatoms to lentic phytoflagellates. This transition was likely facilitated by altered hydrodynamics and possibly influenced by the decomposition of flooded vegetation in the dam's influence zone. The decomposition of this vegetation could explain both the observed increase in oxygen consumption and the subsequent rise in phytoflagellate biomass after damming. However, despite the overall increase in phytoplankton biomass, the values remained within oligotrophic to mesotrophic conditions, consistent with the low nutrient concentrations recorded. However, we caution that the dam-created hydrodynamic conditions are optimal for phytoplankton growth, potentially exacerbating nutrient-related issues in the future. We recommend proactive management strategies to prevent nutrient enrichment from activities such as agriculture and livestock in isolated Amazon areas affected by dams, thereby mitigating potential degradation of water quality linked to increased phytoplankton biomass.

Acoustic mapping reveals macroalgal settlement following a retreating glacier front in the High Arctic

Vegetated coastal marine ecosystems are projected to expand northwards in the Arctic due to climate change, but the mechanisms for this expansion are complex and nuanced. Macroalgal biomass in the littoral areas of Svalbard has been increasing, but data at the glacier fronts are very scarce. In this study, we use hydroacoustics and video validation from an unmanned surface vehicle to survey macroalgal bed distribution along the coast of a High Arctic fjord (Billefjorden, Svalbard), including river bays and land- and sea- terminating glacier fronts, as well as oceanographic measurements to indicate physical drivers of macroalgal settlement. We found high variation of macroalgal coverage along the fjord coastline, with virtually no macroalgae in the river bays but abundant coverage in areas with little terrestrial runoff. Furthermore, the presence of kelp was found at the land-terminating glacier front which has recently retreated from the sea, which suggests the potential for rapid macroalgal establishment in newly available substrate following glacial retreat. These findings suggest large ecological implications throughout the Arctic, in which macroalgal expansion may lead to significant changes in the underwater coastal landscape and ecosystem. This study shows that the use of remote autonomous vehicles and hydroacoustic mapping with video validation has a high potential for sustainable and efficient ecological monitoring.

Dyeing waters: Does indiscriminate dye use threaten aquatic ecosystems?

Aquatic ecosystem conservation is imperative to reaching global biodiversity and sustainability targets. However, the ecological status of waters has been continuously eroded through mismanagement in the face of existing and emerging anthropogenic stressors, such as pollutants. There has been an emerging trend towards the use of dyes to manage algae and plants as well as to alter aesthetics within various aquatic environments. This artificial colouring has potential ecological implications through reductions in light levels and disruptions to thermoclines (i.e., temperature regime changes with depth). Abiotic regime shifts could in turn drive ecological cascades by depowering primary production, hampering top-down trophic interactions, and affecting evolved animal behaviours. Despite commercial dyes being marketed as acutely non-toxic, very little is known about the chronic effects of these dyes across ecological scales and contexts. We thus call for greater research efforts to understand the ecological consequences of dye usage in aquatic environments, as well as the socio-cultural drivers for its application. This emerging research area could harness approaches such as biological assays, community module experiments, remote sensing, culturomics, and social surveys to elucidate dye effects, trends, and perspectives under a pollution framework. A greater understanding of the potential effects of dye in aquatic ecosystems under relevant contexts would help to inform management decisions and regulation options, while helping to mediate ecocentric and anthropocentric perspectives.

Diverse morphology and motility induced emergent order in bacterial collectives.

Microbial communities exhibit complex behaviors driven by species interactions and individual characteristics. In this study, we delve into the dynamics of a mixed bacterial population comprising two distinct species with different morphology and motility aspects. Employing agent-based modeling and computer simulations, we analyze the impacts of size ratios and packing fractions on dispersal patterns, aggregate formation, clustering, and spatial ordering. Notably, we find that motility and anisotropy of elongated bacteria significantly influence the distribution and spatial organization of nonmotile spherical species. Passive spherical cells display a superdiffusive behavior, particularly at larger size ratios in the ballistic regime. As the size ratio increases, clustering of passive cells is observed, accompanied by enhanced alignment and closer packing of active cells in the presence of higher passive cell area fractions. In addition, we identify the pivotal role of passive cell area fraction in influencing the response of active cells toward nematicity, with its dependence on size ratio. These findings shed light on the significance of morphology and motility in shaping the collective behavior of microbial communities, providing valuable insights into complex microbial behaviors with implications for ecology, biotechnology, and bioengineering.

Geographic and environmental impacts on gut microbiome in Himalayan langurs (Semnopithecus schistaceus) and Xizang macaques (Macaca mulatta vestita).

Gut microbiome plays a crucial role in the health of wild animals. Their structural and functional properties not only reflect the host's dietary habits and habitat conditions but also provide essential support for ecological adaptation in various environments. This study investigated the gut microbiome of Himalayan langurs (Semnopithecus schistaceus) and Xizang macaques (Macaca mulatta vestita) across different geographic regions using 16S rRNA gene and metagenomic sequencing. Results showed distinct clustering patterns in gut microbiota based on geographic location. Soil had an insignificant impact on host gut microbiome. Himalayan langurs from mid-altitude regions exhibited higher levels of antibiotic resistance genes associated with multidrug resistance, while Xizang macaques from high-altitude regions showed a broader range of resistance genes. Variations in carbohydrate-active enzymes and KEGG pathways indicated unique metabolic adaptations to different environments. These findings provide valuable insights into the health and conservation of these primates and the broader implications of microbial ecology and functional adaptations in extreme conditions.

Invasive Species and Biodiversity: Mechanisms, Impacts, and Strategic Management for Ecological Preservation

Invasive species, or non-native organisms, pose significant threats to global biodiversity, ecosystems, and economies. This review provides a comprehensive analysis of invasive species, their impact on native biodiversity, and the mechanisms driving their success. Invasive species outcompete native species for resources, disrupt ecosystem functions, and alter habitats, potentially leading to the extinction of native species. The review highlights the ecological, economic, and social implications of invasive species, emphasizing the urgent need for effective management strategies. It examines the invasion pathways, factors influencing their establishment and spread, and the competitive dynamics between invasive and native species. Various assessment methods, including ecological surveys, modelling, and genetic analyses, are discussed to understand and mitigate the impacts of invasions. The review also explores international efforts and policies to manage invasive species and suggests future research directions to enhance conservation strategies. By addressing these issues, this review aims to contribute to the preservation of native biodiversity and the maintenance of ecological balance.

The changes in diversity of vegetation and foliar stable isotopes during the terrestrial plant succession of a subtropical forest and their ecological implications

The disturbed forest system can be restored through successional processes, where changes in the diversity of plant species serves as key indicators of processes. Meanwhile plant water use efficiency and nitrogen dynamics are important factors influencing photosynthesis-water coupling and nutrient stress in plants, respectively, during forest recovery. Analyzing these factors is crucial for understanding forest recovery and promoting sustainable ecosystem development. In this study, traditional vegetation surveys and biodiversity indices, along with foliar stable carbon and nitrogen isotope analyses, as well as nitrogen content analyses, were conducted in a subtropical forest with various successional stages following human and natural disturbances in Sichuan province, China. These analyses were used to assess species diversity patterns, evaluate water use efficiency, and assess nitrogen dynamics in primary, secondary, and artificial forests. The results showed distinct stage-specific differences in succession among forest types. Primary forests exhibited the highest successional stage but were limited by water stress and high nitrogen competition, with the highest δ13C values (i.e., −29.0 ‰), lowest δ15N values (i.e., −3.6 ‰), and the lowest nitrogen contents (i.e., 3.6 %) on average. Artificial forests had the lowest species diversity due to species dominance and nitrogen competition, with the lowest δ13C values (i.e., −29.7 ‰), relatively low nitrogen contents (i.e., 4.0 %), and high δ15N values (i.e., −1.8 ‰). Secondary forests, with longer recovery periods, reached higher successional stage due to sufficient nitrogen and water, which is indicated by the highest δ15N values and nitrogen contents (i.e., −1.7 ‰ and 4.5 %), and the relatively low δ13C values (i.e., −29.4 ‰), leading to accelerated vegetation growth. This study highlights not only the importance of analyzing plant diversity, but also the material cycles, especially water use efficiency, and nitrogen dynamics, to understanding forest recovery. These findings can support effective conservation and sustainable development of subtropical forest ecosystems.

Impact of Arctic Stratospheric Polar Vortex on Mediterranean Precipitation

Abstract The Mediterranean precipitation has significant implications for the local ecology and human livelihoods. This study explores the impact of the Arctic stratospheric polar vortex on the Mediterranean precipitation during the wet season (winter) using reanalysis data and large-scale ensemble experiments that are forced by anomalous stratospheric polar vortex states. Our findings reveal that total and extreme precipitation over the Mediterranean region are increased under weak polar vortex (WPV) conditions and decreased under strong polar vortex (SPV) conditions. Moisture budget suggests that the changes in vertical motion over the Mediterranean play the dominant role in precipitation changes. It is further found that the tropospheric quasi-stationary wave train propagating from Greenland to the European continent is enhanced under WPV conditions, accompanied by warming advection over the eastern Mediterranean and vorticity advection in the upper troposphere over the whole region of the Mediterranean. Consequently, the vertical motion and precipitation there are enhanced. The southward shift of the Atlantic jet stream under WPV conditions leads to enhanced moisture transport toward the Mediterranean, providing a favorable moisture source for precipitation. In addition, the background baroclinicity in the lower troposphere around the northern Mediterranean is enhanced under WPV conditions, intensifying frontogenesis and cyclonic activities, which are commonly accompanied by intensified precipitation. These results are consistent with earlier literature and suggest that the changes in the stratospheric polar vortex may be used as a potential predicting factor for Mediterranean precipitation.

Pre-Copulatory Sexual Selection Predicts Sexual Size Dimorphism: A Meta-Analysis of Comparative Studies.

Size differences between males and females are common across the tree of life (termed sexual size dimorphism; SSD), and have fundamental implications for ecology, life history and behaviour of both sexes. Conventionally, SSD is thought to evolve in response to sex-specific sexual selection but more recent work suggests that ecological processes can also promote sex-differences in size. Here, we provide a global test for the role of sexual selection in the evolution of sexual size dimorphism using data from 77 comparative studies spanning the major classes of the animal kingdom. We show that intense sexual selection typically correlates with male-biased SSD across species. Importantly, pre-copulatory but not post-copulatory sexual selection predicts SSD, suggesting a pervasive role of premating male-male competition and female choice to drive sex differences in body size. Collectively, our findings suggest that pre-copulatory sexual selection plays a major role in the evolution of male-biased SSD.

Caring for Creation in Julian of Norwich's Parable of the Lord and Servant

Abstract: This essay expands upon the ecological implications of Julian's theology by arguing that her parable of the lord and servant exemplifies the call in Genesis 2:15 to cultivate and tend to Earth and all fleshly creatures. In conversation with present-day ecological theologies, I contend that Julian's example re-presents Genesis's theological claim that love of God is embodied by care for Earth and neighbor. When human persons are inhibited from laboring in the garden, they suffer from isolation and fall prey to despair. Julian's Revelation offers a spiritual resource to motivate ecological conversion, as Pope Francis urges in Laudato Si' .

Vegetation Cover Change in the Loess Plateau: Patterns, Driving Factors, and Impacts

This paper reviews the changes in vegetation cover in the Loess Plateau, focusing on patterns, driving factors, and impacts. Over recent decades, significant improvements in vegetation cover have been observed, primarily due to large-scale ecological restoration projects and natural climate variability. Key drivers include precipitation, temperature, land use changes, and human activities such as reforestation. These changes have important ecological, socio-economic, and hydrological implications, including reduced soil erosion, improved biodiversity, and potential trade-offs with water availability. Understanding these dynamics is crucial for sustainable land management and ecological conservation in the region.

An Economic Insights of Agricultural Sustainability in the Himalayan Districts of Jammu and Kashmir, India

The agriculture scenario has witnessed a tremendous change after the independence of the Indian subcontinent. It had undergone number of reforms to protect both supply and demand side interests. The food security was ensured by increasing its production and the country has emerged as one of the top producers of number of commodities. The commercialization of agriculture shifted subsistence farming to a more market-oriented approach, where agricultural production is primarily aimed at generating income and participating in the market economy which involves increased scale of production, adopting modern technologies and focusing on cash crops and high – value commodities. However the unscientific use of these resources and indispensable application of inputs has led to several drawbacks like labour migration, shift to monoculture practices, decline in the water table, vulnerabilities in terms of food security during market fluctuations. Creating concerns of sustainability needs an immediate attention. Sustainability is to be assured to ensure food supply and for the balanced economic growth. Agricultural sustainability in Jammu and Kashmir is influenced by various factors. It provides production environment to a number of niche crops including apple, walnut, saffron, vegetables, major agriculture products etc., But its agriculture faces the unique environmental, social and economic challenges, despite known for their rich ecological diversity. Though essential, the urbanization results in the shift of productive land to undesirable use which may lead to ecological implications. This background necessitated a comprehensive attempt to examine the sustainability of agriculture in relationship with various economic, ecological and social indicators with an intention to come up with findings having greater policy implications for long term sustenance of agrarian economy in J&K. Shopian(0.604) ranked first among all the districts in terms of Agricultural sustainability, followed by Jammu(0.598) and Kathua(0.564) and least performing districts were found to be Srinagar(0.406), followed by Ramban(0.413) and Kupwara(0.420). The calculated Composite Sustainability Index helps us to differentiate the districts based on their index value under various categories of the sustainability level.

Comprehensive Assessment of Herbicide Toxicity on Navicula sp. Algae: Effects on Growth, Chlorophyll Content, Antioxidant System, and Lipid Metabolism.

This study investigated the effects of herbicide exposure on Navicula sp. (MASCC-0035) algae, focusing on growth density, chlorophyll content, antioxidant system, and lipid metabolism. Navicula cultures were exposed to different concentrations of atrazine (ATZ), glyphosate (Gly), and acetochlor (ACT) for 96 h. Results showed a significant decrease in cell numbers, with higher herbicide concentrations having the most noticeable impacts. For instance, Gly-G2 had reduced cell populations by 21.00% at 96 h. Chlorophyll content varied, with Gly having a greater impact on chlorophyll a compared to ATZ and ACT. Herbicide exposure also affected the antioxidant system, altering levels of soluble sugar, soluble protein, and reactive oxygen species (ROS). Higher herbicide rates increased soluble sugar content (e.g., ATZ, Gly, and ACT-G2 had increased by 14.03%, 19.88%, and 19.83%, respectively, at 72 h) but decreased soluble protein content, notably in Gly-G2 by 11.40%, indicating cellular stress. Lipid metabolism analysis revealed complex responses, with changes in free proline, fatty acids, and lipase content, each herbicide exerting distinct effects. These findings highlight the multifaceted impacts of herbicide exposure on Navicula algae, emphasizing the need for further research to understand ecological implications and develop mitigation strategies for aquatic ecosystems.

Soil Microbial Biomass and Microarthropod Community Responses to Conventional and Biodegradable Plastics

Plastic mulch is a commonly employed technique in agriculture to enhance crop production. Given the persistence of plastic residues in soil, bioplastics offer a potential alternative. Unfortunately, little is known about the medium-term consequences of both plastic and bioplastic mulches on soil properties. This study aimed to assess the medium-term consequences of plastic and bioplastic mulches and their replacement on soil properties. To this aim, the impact of conventional plastic (polyethylene, CP) and biodegradable plastic (BP) mulches on soil’s abiotic (pH, water content, total and organic carbon and total nitrogen contents) and biotic (microbial biomass, microbial respiration, enzymatic activities and microarthropod communities) properties after 2 years of exposure (T1) and after 3 (T2) and 6 (T3) months of mulch replacement was investigated. Moreover, uncovered soils were assessed as a control. The results highlighted that the samples were more significantly impacted by exposure time to mulches than by the different kinds of mulches. The replacement of both mulches (T2 and T3) decreased the content of C and increased the microbial biomass and activities; moreover, the mulch replacement changed the microarthropod community composition with a decrease of Collembola and an increase of Oribatida and Gamasida, especially in soils covered by biodegradable plastic mulches. Further investigations are needed to better understand the long-term impact of mulches on soil biota in order to prove the potential ecological implications of transitioning to sustainable alternatives.

On the tail of two species: The changing place of the peregrine falcon in society

Abstract Wildlife conservation can become contentious when human interests are impinged. For peregrine falcons (Falco peregrinus) in the United Kingdom, their iconic status as a protected species is contested by pigeon racers and falconers restrained by strict wildlife policies. However, even entrenched conservation policies can shift, sparking controversy. This paper seeks to understand the conditions leading to recent conservation policy shifts and conflicts. Through archival research and discourse analysis of falconry and pigeon racers' rhetoric, I review the development of 150 years of UK wildlife legislation and politics surrounding peregrines, situating present‐day conflict within long‐standing tensions between competing interests. In doing so, I demonstrate how contrasting ideologies of the raptors existed simultaneously between groups. Each vied for dominance and influenced policies over time, with the ideologies of ‘winners’ suppressing that of the ‘losers’ to become the norm. This historical approach highlights the key role global events like war played in overpowering the dominance of protective ideologies towards peregrines domestically, allowing peregrine culls and capture to become socially permissible. Conversely, post‐War environmental movements originating in the United States suppressed falconry's extractive relationships with peregrines in the United Kingdom, entrenching ecological priorities as a norm still conventional today. I argue that wildlife protection is contested because cultural extinction of falconry and pigeon racing were imminent, brought on by policymakers' focus on preventing the biological extinction of peregrines. However, recent policy shifts highlight the acceptance of anthropocentric interests within conservation practices. Policy implications: Animals can play multiple roles in society, but the public may not be accustomed to anthropocentric interests overtly displayed within contemporary conservation practices. Policy needs to be more sensitive towards accommodating or communicating human interests, but to also reflect on the social and ecological implications of their own ideologies towards conservation. Read the free Plain Language Summary for this article on the Journal blog.

Investigating the ecological and toxicological significance of Cyanox®53 recovered from intertidal sediments and varnish clam

We examined the ecological and toxicological implications of the microplastic, Cyanox®53, found in sediments and varnish clams across seven beaches in Burrard Inlet, British Columbia (BC). Using the simulation models embedded within Estimation Programs Interface (EPI) Suite™, the potential persistence, bioaccumulation, and toxicity of Cyanox®53 was assessed to evaluate the risk to varnish clams foraging on sediment containing this contaminant. Moreover, we used a bioenergetic model, based on the blue-listed surf scoter species, to estimate the risk of daily ingestion of Cyanox®53 per body weight in overwintering seabirds. Our findings indicate that varnish clams collected from Burrard Inlet accumulate on average 0.46 particles of Cyanox®53/clam, and based on bioenergetic modeling, results in surf scoters potentially consuming 78 (for males) to 83 (for females) pieces of Cyanox®53 daily from foraged varnish clams. EPI Suite™ predicted Cyanox®53 to be persistent, however, unlikely to bioaccumulate as a “traditional” chemical. Furthermore, the estimation of potential acute and chronic toxicity of Cyanox®53 to aquatic organism surrogates, such as fish, Daphnia magna, and green algae, was inconclusive due to model variability and limitations within EPI Suite™. To fully understand the potential risks of Cyanox®53 further investigation is warranted.

Trashy treasures? The increasing terrestrial invertebrate diversity in small-scale dumps

The research on the impact of plastic pollution on biodiversity has primarily focused on aquatic ecosystems, especially marine ones. Therefore, it is vital to assess how plastic pollution affects other environments and organisms, including terrestrial invertebrates. These organisms are widely recognized for their susceptibility to environmental changes and pollution. The objectives of this study were i) to investigate the potential influence (positive or negative) of macroplastic debris (MaP) on invertebrates inhabiting riverine sandy environments, ii) the potential occurrence of the microplastic (MP) adherence phenomenon on the invertebrate's body by entanglement on the body's setae or electrostatic effect (i.e., bioadhesion), and iii) the effects of removal of debris on the colonized diversity. By performing a mesocosm experiment, emulating a “small-scale dump” (also called micro-waste sites), we found that terrestrial invertebrates show a preference for colonizing areas rich in MaP, resulting in higher species richness in these areas (39 taxa in areas containing plastic debris vs. 21 taxa in areas free of plastics). This preference is likely due to the provision of shade, protection, and distinct micro-habitats offered by MaP. Regarding MP, we observed a significant number of invertebrates with MPs attached to their bodies (4.3 ± 0.8 MPs attached per individual), mainly wolf spiders (Lycosidae) and ground beetles (Carabidae), suggesting potential negative ecological implications that are discussed herein.

Feeding habits and ecological implications of the invasive Flathead Catfish in the Susquehanna River basin, Pennsylvania

AbstractObjectiveFlathead Catfish Pylodictis olivaris are a widespread aquatic invasive species within the United States and a recent invader in the Susquehanna River basin, Pennsylvania. Flathead Catfish are piscivores known to consume native and recreationally important fish species. In the mid‐Atlantic United States, it is unknown how this invader is impacting food webs and which species may be at greatest predation risk. To address this knowledge gap, we DNA barcoded stomach contents collected from Flathead Catfish to identify prey species and elucidate potential predatory impacts of Flathead Catfish in the Susquehanna River.MethodsWe used a Bayesian hierarchical multivariate probit model to investigate if the probability of prey species occurrence in the diets of Flathead Catfish varied seasonally or was a function of Flathead Catfish length.ResultA total of 576 Flathead Catfish were collected during 2020–2021, with 241 individuals having recoverable stomach contents. In all, we identified 47 different prey species. The most common prey species were rusty crayfish Faxonius rusticus, Margined Madtom Noturus insignis, and shiners Notropis spp. While frequency of occurrence of prey species differed across Flathead Catfish length classes (<300 mm, 301–600 mm, 601–900 mm TL), rusty crayfish were commonly found (33.7–44.0% of diets) in stomachs of all size‐classes.ConclusionWe found that Flathead Catfish length and seasonality did influence occurrence probability differentially for several prey species. For example, Channel Catfish Ictalurus punctatus were more likely to appear in shorter Flathead Catfish while Smallmouth Bass Micropterus dolomieu appeared in larger Flathead Catfish. We demonstrate significant variation in Flathead Catfish predation, increasing our understanding of predator–prey dynamics, which is necessary to better manage and identify future impacts to aquatic communities in the Susquehanna River basin.

Evaluation of Bisphenol S (BPS) toxicity on the reproductive system of Channa striatus: Insights for environmental risk assessment

Aquatic ecosystems face significant exposure to endocrine-disrupting chemicals (EDCs), which can mimic, block, or alter the synthesis of endogenous hormones. Bisphenol A (BPA), a widely known EDC, has been phased out from consumer products due to concerns about its potential impacts on human health. In its place, bisphenol S (BPS), an organic compound, has been increasingly used in the production of polycarbonate plastics, epoxy resins, thermal receipt papers, and currency. Vitellogenin (Vtg), a yolk precursor protein synthesized in the liver and present in oviparous fish, particularly males, serves as a pertinent biomarker for studying the effects of estrogenic EDCs on fish. This study aimed to assess the impact of BPS on reproductive parameters and hepatic vitellogenin expression in Channa striatus. The LC50 of BPS was determined to be 128.8 mg/L. Experimental groups included control and BPS-exposed fish, with sub-lethal concentrations of BPS (1 mg/L, 4 mg/L, and 12 mg/L) administered and effects monitored at seven- and twenty-one-day intervals. Significant decreases in gonadosomatic index (GSI), ova diameter, and fecundity were observed in BPS-exposed Channa striatus. Hepatic Vtg mRNA expression was downregulated in female and upregulated in male following BPS exposure. Serum hormone analysis confirmed the estrogenic activity of BPS. These findings underscore BPS's ability as an endocrine disruptor to interfere with hormone synthesis and disrupt spermatogenesis and oogenesis processes in Channa striatus. This research contributes to understanding the endocrine-disrupting effects of BPS on aquatic organisms, highlighting potential ecological implications and the need for continued monitoring and regulatory considerations.