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In recent years, recognition has grown of the significant role that food systems play in driving climate change, constituting about one-third of global greenhouse gas emissions, while also playing a key role in sequestering carbon and adapting to climate changes. The COP28 climate conference signaled a pivotal shift, spotlighting food and agriculture in discourse. However, despite pledges and declarations, concrete plans and targets to address emissions from food chains remain elusive. Urgent action is imperative to transform food systems and avert surpassing critical warming thresholds. [ABSTRACT FROM AUTHOR]

Post-sale customer care (PSCC) outsourcing is an effective supply chain strategy to reduce costs, but traditional outsourcing methods cannot ensure consumers' belief in PSCC quality, harming the firms' competitive strategy. To ensure consumer satisfaction through transparency, this article examines evolving supply chain strategies of leveraging blockchain to outsource PSCC operations of competing manufacturers to third-party agents. Based on consumers' beliefs and blockchain adoption cost, manufacturers have two choices; to outsource the PSCC operations with or without blockchain, resulting in multiple outsourcing strategies. Results show that the consumers' belief in one manufacturer's outsourcing strategy has detrimental effects on the stance of another manufacturer. Moreover, the blockchain cost and consumers' beliefs dictate the manufacturers' strategies for PSCC outsourcing, resulting in a 'quadruple zone of strategic fit', where both manufacturers adopt blockchain or neither adopt blockchain, or one adopts while the other does not. Interestingly, despite the low or zero blockchain cost, both manufacturers will outsource without blockchain if their traditional business models satisfy consumers. The extended analysis reveals contradictory results that manufacturers should outsource more often with blockchain to facilitate consumers when a long-term warranty is offered, or the product has a higher failure rate, even though, overall these factors increase costs. [ABSTRACT FROM AUTHOR]

Corporate environmental responsibilities have expanded to include their supply chains. Green supply chain management (GSCM) practices can be extensive – including both intra- and inter-organisational environmental management practices. Selecting and sequencing GSCM practices is an important issue given resource and strategic organisational considerations. Using the cumulative capabilities theory, this study empirically explores GSCM implementation sequences, following which firms can build cumulative capabilities. Correlation, sequential test, and path analysis are used to identify GSCM practice implementation sequence from secondary data. The results show that firms should first encourage suppliers to disclose their environmental data and respond to inquiries on environmental violations by their suppliers (the order of the two is exchangeable), then encourage suppliers to comply with environmental regulations, extend practices to lower-tier suppliers, and engage in responsible recycling. This study is one of the first to apply cumulative capability theory to analyse environmental practices and provides a framework for future research on GSCM sequences. The paper also offers practical implications for firms to adjust their strategies in order to adopt GSCM more effectively and successfully. [ABSTRACT FROM AUTHOR]

ABSTRACT In this work, we investigate the native parasitoid community colonising galls by an invasive pest: the oriental chestnut gall wasp (OCGW), Dryocosmus kuriphilus (Hymenoptera; Cynipidae). We tried to understand how native parasitoids react after the arrival of the pest (two‐year sampling period) in the province of Zamora (Castilla & León region, N‐W Spain). For this purpose, we collected both, chestnut galls from six stands and oak galls from surrounding oak groves. Our results highlight the response to D. kuriphilus provided by the oak gall wasps that naturally inhabit Quercus pyrenaica. The parasitoid community showed a core assemblage composed of Eurytoma brunniventris, Torymus flavipes and T. sinensis in OCGW galls, and Baryscapus diaphantus, Bootanomyia dorsalis, Eupelmus urozonus, E. brunniventris, Mesopolobus lichtensteini, T. affinis, and T. flavipes in oak galls. We identified the torymid T. flavipes as one of the most common parasitoids of OCGW, in addition to the exotic parasitoid T. sinensis, never officially released in the region but present in the study area. In addition, we intend to know its possible incidence on non‐target cynipids. We have found an intense connection in the food web with some chalcids that establish interactions with the gall wasp, both in adult instar (emerging from reared galls) and larval (presence of larvae in OCGW gall chambers, identified by dissection). We also describe the flight phenology of D. kuriphilus in our study area (as far as we know, the first one focused in Castilla & León region) and evaluate the overlap between OCGW and native and exotic parasitoids showing a promising role of native guild as biocontrollers. [ABSTRACT FROM AUTHOR]

Temperature increases will have ubiquitous effects on aquatic food webs, from microbes to consumers, and affect the quality and quantity of carbon flows within and between water layers. A decline in the biological pump moving carbon from surface to lower layers is anticipated. We reviewed 37 years of data on hypoxic zone size and water quality in the northern Gulf of Mexico to determine if air and bottom water temperature increases (0.5°C decade−1) are significantly related to variations in its areal size. There was no significant decline in important river water quality in the 24 years since the national Hypoxia Action Plan was developed to reduce its size. Changes in the ratio of km2 hypoxia per 1000 mt nitrate loading from the Mississippi River from 2000 to 2023 reveals a tipping point in the hypoxic zone size that is driven by ocean warming. Biological factors varying with temperature such as ectotherm growth rates, zooplankton grazing, cell sinking rates, and diatom sequestration of Si or N are apparently more important influences on recent hypoxic zone size than variations in physical factors. This tipping point may be common to similarly warmed and eutrophic coastal waters where warming will likely result in diminished oxygen deficiency (< 2 mgO2 L−1). Hypoxia and food web models assuming a stationary equipoise of nutrient loadings, ratios and food webs will be deficient as coastal waters warm further, coastal storm and hurricane frequency increase and land uses in the watershed are altered with climate change. [ABSTRACT FROM AUTHOR]

The removal or addition of a predator in an ecosystem can trigger a trophic cascade, whereby the predator indirectly influences plants and/or abiotic processes via direct effects on its herbivore prey. A trophic cascade can operate through a density‐mediated indirect effect (DMIE), where the predator reduces herbivore density via predation, and/or through a trait‐mediated indirect effect (TMIE), where the predator induces an herbivore trait response that modifies the herbivore's effect on plants. Manipulative experiments suggest that TMIEs are an equivalent or more important driver of trophic cascades than are DMIEs. Whether this applies generally in nature is uncertain because few studies have directly compared the magnitudes of TMIEs and DMIEs on natural unmanipulated field patterns. A TMIE is often invoked to explain the textbook trophic cascade involving wolves (Canis lupus), elk (Cervus canadensis), and aspen (Populus tremuloides) in northern Yellowstone National Park. This hypothesis posits that wolves indirectly increase recruitment of young aspen into the overstory primarily through reduced elk browsing in response to spatial variation in wolf predation risk rather than through reduced elk population density. To test this hypothesis, we compared the effects of spatiotemporal variation in wolf predation risk and temporal variation in elk population density on unmanipulated patterns of browsing and recruitment of young aspen across 113 aspen stands over a 21‐year period (1999–2019) in northern Yellowstone National Park. Only 2 of 10 indices of wolf predation risk had statistically meaningful effects on browsing and recruitment of young aspen, and these effects were 8–28 times weaker than the effect of elk density. To the extent that temporal variation in elk density was attributable to wolf predation, our results suggest that the wolf–elk–aspen trophic cascade was primarily density‐mediated rather than trait‐mediated. This aligns with the alternative hypothesis that wolves and other actively hunting predators with broad habitat domains cause DMIEs to dominate whenever prey, such as elk, also have a broad habitat domain. For at least this type of predator–prey community, our study suggests that risk‐induced trait responses can be abstracted or ignored while still achieving an accurate understanding of trophic cascades. [ABSTRACT FROM AUTHOR]

In the Southern Ocean, myctophids (family Myctophidae) are speciose, dominate the mesopelagic fish biomass, and are important in the diets of many fishes, squids, seabirds, and marine mammals. Consequently, they play a key role in carbon export and energy transfer from primary consumers to top predators. However, they are delicate and rarely found intact in predator stomachs, which makes them difficult to identify to species. Fortunately, their otoliths (sagittae) are mostly distinctive and therefore useful for species identification. Previous studies describing Southern Ocean myctophid otoliths were often limited by small sample sizes or focused on only a few species. To facilitate myctophid identifications in diet studies, we provide scanning electron microscope images of otoliths with brief descriptions for 37 species of Southern Ocean myctophids. The identities of problematic taxa were confirmed with DNA. Most species were found to have distinctive otoliths, which can be used to identify them to the species level. Large Gymnoscopelus piabilis otoliths comprised two types, which may represent different species. In addition, allometric equations are provided for 32 species to enable back calculation of fish size. [ABSTRACT FROM AUTHOR]

The Chinese mitten crab (Eriocheir sinensis) holds significant importance as a popular aquaculture food source; however, there are concerns about its potential contamination with polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) from both food and aquatic environment. To assess the associated health risks and identify potential sources of contamination in crabs, a comprehensive investigation was conducted, including a total of 70 samples from the crab food web. The results demonstrated that crabs predominantly exhibited elevated concentrations of PCBs and dl-PCBs, with mean concentrations of 12 207 ± 11 962 pg g-1 and 554 ± 203 pg g-1, respectively, while PCDD/Fs concentrations were comparatively lower at 20 ± 17 pg g-1. The accumulation of PCBs in crabs significantly surpassed that of PCDD/Fs. The material balance of PCDD/Fs and PCBs in the crab food web was estimated, indicating that sediments and feeds likely constitute the two primary sources of PCDD/Fs and PCBs in crabs. The monthly intake of PCDD/Fs and PCBs through crab consumption accounted for 30% of the dietary intake, which was well below the provisional tolerable monthly intake (PTMI) limit. The weekly intake of PCDD/Fs and PCBs for adults consuming one crab (100 g) does not pose health risks and the recommended weekly intake of white crabmeat and brown crabmeat is 443 g and 21 g, respectively. [ABSTRACT FROM AUTHOR]

Consumers are thought to select food resources based on their nutritional content. While laboratory experiments have explored this, the nutritional dynamics of invertebrate predators have been scarcely studied in the field given various methodological constraints. The intersection of these nutritional dynamics with predator traits is also poorly characterised, leading to many gaps in our understanding of how different predators forage and feed in natural systems. Here, we integrate dietary metabarcoding with prey macronutrient (protein, lipid and carbohydrate) content and abundance to assess how nutrients and predator traits (sex, life stage and taxonomy) interactively drive prey preferences in the field, using spider–prey interactions as a model system. Different spider genera, sexes and life stages had nutritionally distinct diets. Our analyses demonstrated disproportionate foraging (selection and avoidance) for prey rich in different macronutrients, with the nature of these relationships differing between spider taxa, life stages and sexes. This may be explained by niche differentiation among spider groups, driven by biases toward prey rich in different nutrients, or nutrient‐specific foraging in which individual spiders vary their nutritional preferences to redress deficits, although further evidence is required to confirm this. This insight into the nutritional dynamics of generalist invertebrate predators extends our understanding beyond lab‐based behavioural assays and provides a novel framework for other complex real‐world systems. [ABSTRACT FROM AUTHOR]

Protists, an umbrella term first coined by Ernst Haeckel in 1866, are a vast collection of (primarily unicellular) eukaryotes that are "neither animals nor plants". This basic definition by exclusion has been exercised for centuries, even though recent advances have led to more rigorous taxonomic assignment of various protist groups. Pioneering comparative phylogenetic approaches have been applied to these organisms to reconstruct the deep branches of the eukaryotic tree, revealing essential clues about early eukaryotic evolution. Protists, including amoebae, flagellates, ciliates, and algae, are also vital constituents of global ecosystems, where they appear at the base of food chains, control the relative abundance of other microbes, and participate in global biogeochemical recycling. Due to their typically small size and lack of nervous systems, protists are often associated with the unfortunate label 'primitive'. Yet they exhibit remarkable behavioural sophistication and are able to feed, predate, navigate and interact with their surroundings. Unlike macroscopic animals, many protists reside in a non-intuitive physical regime where viscous forces dominate over inertia, and where they use diverse propulsion and navigation strategies. Interdisciplinary research into these cell-scale phenomena, characterised by a complex interplay of physical forces and mechanical constraints, has significantly advanced the emerging fields of active matter, microhydrodynamics, and non-equilibrium statistical physics. This primer discusses the biophysics of protist behaviour, with a focus on locomotion and feeding. I will highlight the most extensively studied principles and describe some more esoteric behaviours that have not yet been systematically explored. Kirsty Wan discusses the biophysics of protist behaviour, with a focus on locomotion and feeding, highlighting the most extensively studied principles and describing some more esoteric behaviours that have not yet been systematically explored. [ABSTRACT FROM AUTHOR]

Summary Staphylococcus aureus can cause food poisoning and human infections and CC5 and CC398 are relevant lineages in the animal‐human interface. The objective was to determine the S. aureus prevalence in chicken‐derived food, and to study the diversity of lineages, and their antimicrobial resistance and virulence genotypes. Sixty poultry‐food samples were processed, and the S. aureus isolates obtained were characterised. Antibiotic susceptibility was performed and the presence of resistance/virulence genes, and avian mobile genetic elements (MGEs) was studied. Forty‐four non‐repetitive S. aureus isolates were obtained of 28/60 samples (46.7%), and 43 methicillin‐susceptible (MSSA) and one methicillin‐resistant S. aureus (MRSA) isolates were detected. Five S. aureus isolates were multidrug‐resistant and 50% of isolates showed susceptibility to all tested antibiotics. Eighteen spa‐types, 11 sequence‐types and 8 clonal‐complexes were identified in the S. aureus collection. Three CC398 isolates (2 MSSA/1 MRSA) of spa‐type‐t1451 were detected, and MSSA‐CC398 isolates harboured the scn‐gene (absent in MRSA‐CC398). CC5 was the most frequent lineage identified (56.8%), all MSSA, and 56.7% of them contained avian‐MGEs. A high prevalence of avian‐adapted MSSA‐CC5 isolates was detected. Poultry meat has been shown to be a vehicle for CC398‐t1451 isolates, both MRSA and MSSA, showing characteristics of the animal and human clades, respectively. [ABSTRACT FROM AUTHOR]

Plastic is a ubiquitous environmental contaminant, resulting in widespread exposure across terrestrial and marine spaces. In the environment, plastics can degrade into microparticles where exposure has been documented in a variety of fauna at all trophic levels. Human epidemiological studies have found relationships between inhaled microplastics and oxidative stress and inflammation. Previous studies of bottlenose dolphins (Tursiops truncatus) have reported prevalent exposure to plasticizing chemicals (e.g., phthalates) as well as particle loads in gastrointestinal tracts, but exposure from inhalation has not yet been studied. The objective of this study was to determine if inhalation is a viable route of microplastic exposure for free-ranging dolphins. Exhalation samples were opportunistically collected from dolphins residing in Sarasota Bay, Florida (n = 5) and Barataria Bay, Louisiana (n = 6) during catch-and-release health assessments to screen for microplastic particles. All dolphin samples contained at least one suspected microplastic particle, and polymer composition was determined for 100% of a subset (n = 17) of samples. Additional studies are warranted to better understand the extent of inhaled microplastics, as well as to explore impacts, given potential risks to lung function and health. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Materials and Methods Results Discussion Nutritional changes over the last century, driven by globalization, hypermarketization, and malnutrition, are global in scale. Large countries in the Global South might be resilient to dietary homogenization due to their natural diversity of regions and ecosystems, which might have prevented the adoption of supermarket diets. Argentina has a wide array of ecosystems and historically different subsistence diets dependent on regional characteristics. We analyzed the spatiotemporal variation of stable isotope values in Argentina using modern teeth to test for regional dietary patterns and its consistence over time.We collected teeth from voluntary donors born between 1940 and 2010, from 72 locations across Argentina. A total of 119 teeth were analyzed for the markers δ13Cdentine, δ13Cenamel, δ15N, and δ34S. A reconstruction of isotopic niches was performed to estimate dietary patterns across different regions and time periods.This study is the first to analyze changes in modern dietary patterns in Argentina using isotopic data measured in contemporary teeth. We showed latitudinal, longitudinal, and temporal differences in isotopic values, reflecting the variation in available resources within the country. Changes in the diet were observed over time, including declining δ15N values, a reduction in δ34S range, and a trend toward homogenization of δ13Cenamel values. Conversely, δ13Cdentine values remained constant over time, maintaining latitudinal patterns and regional differences across regions.This study increases our understanding of modern population dietary patterns both spatially and over the last 70 years. Our findings suggest that the Argentine population has shifted toward a supermarket diet in recent years. [ABSTRACT FROM AUTHOR]

AbstractListeria monocytogenes, a resilient bacterium in diverse food conditions, such as refrigeration, reduced water activity and low pH, poses a significant threat to the food industry and public health. In recent years, it has been documented an increase in the antibiotic resistance of zoonotic pathogens, including L. monocytogenes. This review provides new insight into the molecular mechanisms involved in both intrinsic and acquired antibiotic resistance of L. monocytogenes with an emphasis on the effect of different environmental and food-related factors. It also explores the relationship of these resistance mechanisms with virulence factors. An analysis of literature data (2009–2021) was conducted to investigate statistically and graphically potential associations between specific antibiotic resistance patterns in the pathogen and food categories using an unbiased variance analysis. The results evidenced that food type had an influence on the antibiotic resistance profiles of L. monocytogenes, with meat and vegetables being the food categories exhibiting the most prevalent profiles. The frequent detection of resistance to ampicillin, penicillin, and tetracycline (non-intrinsic resistances) indicates that specific processing conditions along the food chain may induce them. Many questions remain about the impact of food chain factors (e.g. thermal treatments, cold chain, preservatives, etc.) and food type (low pH, reduced water activity, etc.) on the antibiotic resistance patterns of the pathogen, particularly concerning food-related sources, the resistance mechanisms involved (e.g. cross-protection, horizontal gene transfer, etc.), and the evolutionary processes of antibiotic-resistant microbial populations. Metagenomics, in addition to other –omics technologies (metabolomics and transcriptomics), allows a better understanding of the processes involved in the acquisition of resistance. [ABSTRACT FROM AUTHOR]

Many primary consumers in freshwater, marine and terrestrial systems are ectotherms (e.g. zooplankton and insects), whose metabolisms, and therefore nutritional demands, are modulated by temperature. Further, nutrient availability largely influences the quality of resources consumed by these organisms, and hence affects whether nutritional demands of consumers are fulfilled. From these considerations, a crucial question arises: how do temperature and nutrient availability together modulate trophodynamics at the basis of food webs? Addressing this question for zooplankton and insects is essential since these consumers are the most abundant metazoans on Earth, and they link primary production to higher trophic levels. Here, we synthesize the existing literature and offer avenues to guide future scientific endeavours. We highlight that the vast majority of studies on the combined influence of temperature and nutrient availability published to date focus on at least one of the following research topics: 1) metabolic requirements of ectotherms; 2) feeding behaviour; 3) eco‐evolutionary processes; and 4) trophodynamics. We pose that further advances in this field of research may provide a robust understanding of how modulations of consumer metabolic requirements and resource quality define consumer–producer interactions across marine, freshwater and terrestrial ecosystems. This research effort would enable to combine the fields of Ecological stoichiometry and of Metabolic theory of ecology, and create an integrated approach, which we propose to call Nutritional thermal ecology. [ABSTRACT FROM AUTHOR]

Introduction: Bivalve aquaculture has direct and indirect effects on plankton communities, which are highly sensitive to short-term (seasonal, interannual) and long-term climate changes, although how these dynamics alter aquaculture ecosystem interactions is poorly understood. Methods: We investigate seasonal patterns in plankton abundance and community structure spanning several size fractions from 0.2 µm up to 5 mm, in a deep aquaculture embayment in northeast Newfoundland, Canada. Results: Using flow cytometry and FlowCam imaging, we observed a clear seasonal relationship between fraction sizes driven by water column stratification (freshwater input, nutrient availability, light availability, water temperature). Plankton abundance decreased proportionally with increasing size fraction, aligning with size spectra theory. Within the bay, greater mesozooplankton abundance, and a greater relative abundance of copepods, was observed closest to the aquaculture lease. No significant spatial effect was observed for phytoplankton composition. Discussion: While the months of August to October showed statistically similar plankton composition and size distribution slopes (i.e., food chain efficiency) and could be used for interannual variability comparisons of plankton composition, sampling for longer periods could capture long-term phenological shifts in plankton abundance and composition. Conclusions provide guidance on optimal sampling to monitor and assess aquaculture pathways of effects. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a persistent pollutant highly bioaccumulated in the aquatic environment through the food chain reaching high concentration levels in the tissues of predator fishes. Among the relevant sources of anthropogenic mercury emissions in Latin America and the Caribbean (LAC), mining is one of the most important along with soil erosion due to deforestation and agricultural activities where pesticides are intensively used. Several reports have demonstrated an association between a fish-based diet with elevated Hg levels in the blood and neurotoxic effects in humans. In this systematic review with quantitative analysis data from 92 articles were compiled, providing evidence of Hg concentration in fishes that are commonly consumed in LAC. An assessment was conducted using three indices for health risk: the Minamata Initial Assessment (MIA), the Target Hazard Quotient (THQ), and the Meals per Week (MPW) index. Of the 410 fish species studied, 5.4% had concentrations above 0.95 μg g-1 of wet weight (ww), which is the recommended limit for Total Hg (THg) ingestion through fish consumption according to the MIA index, regardless of the water habitat (i.e., marine or freshwater). Additionally, the Target Hazard Quotient (THQ) calculation indicated high-risk values (THQ ≥ 1) in 15 out of the 19 countries studied, and very high-risk values (THQ ≥ 10) were obtained from Hg concentrations measured in 5 fish species inhabiting watersheds in Trinidad and Tobago, Suriname and Peru. Finally, recommendations on fish consumption were made based on the MPW index. This study reveals the need for updated biomonitoring studies of Hg concentrations in fish to perform more accurate human health risk analyses. [ABSTRACT FROM AUTHOR]

The intrusion of the Pearl River plume into the Taiwan Strait provides a unique case study that challenges traditional assumptions about the impacts of nutrientrich river plumes on coastal phytoplankton communities. In this study, we conducted a detailed analysis of nutrient dynamics and phytoplankton composition within the Taiwan Strait, focusing on the effects of the Pearl River plume. Our findings reveal significant nutrient depletion, particularly of nitrogen, in the surface waters as the plume extends seaward, resulting in nitrogen limitation and a marked reduction in phytoplankton biomass. Vertical stratification within the Taiwan Strait creates distinct ecological niches, with the mid-layer supporting a deep chlorophyll maximum and the surface layer becoming dominated by the picophytoplankton Synechococcus. This shift from diatom-dominated communities to Synechococcus dominance has farreaching implications for carbon cycling and food web dynamics in the region. Our results suggest that the Pearl River plume's influence on the Taiwan Strait represents a departure from the typical nutrient enrichment associated with river plumes, highlighting the complexity of coastal biogeochemical processes. [ABSTRACT FROM AUTHOR]

In this paper, we apply the second‐order averaging theory for obtaining an explicit expression of the small amplitude periodic solution that bifurcates from a zero‐Hopf equilibrium point of a tritrophic food chain model. This model considers logistic growth rate for the lowest trophic level, Holling functional responses type III for the middle and for the highest level. We first prove that this model has a zero‐Hopf equilibrium point, after we show that from this equilibrium bifurcates a small limit cycle, and finally, we provide the explicit expression of the first two terms in the power series of this limit cycle. These differential systems for which the equilibrium point is non hyperbolic are not easy to study, in particular, if the equilibrium is zero‐Hopf. As far as we know, this is the first time that the averaging theory has been used to exhibit the first and second terms of the power series expansion of the analytical expression of a limit cycle that bifurcates from a zero‐Hopf equilibrium in the food chain models. [ABSTRACT FROM AUTHOR]

Potentially toxic metals and metalloids (PTMs) may become a concern to plant and animal health when soil concentrations exceed toxicity limits. These limits are often exceeded in polluted environments (anthropogenic sources) and may transfer through the trophic system, from contaminated soil to plants, and thereafter to herbivores and predators. The aim of this mini review was to consider trophic transfer of PTMs in terrestrial ecosystems, focusing on arthropods as the endpoint. ScienceDirect® was used as search engine with a set of keywords. The most assessed PTMs were Cd, Pb, and Zn, and 63% of all PTMs considered in research were attributed to anthropogenic sources. Industrial or mining sites were most frequently studied, and agricultural sites the least. Brassica was the most studied plant genus as the main extractor of PTMs from the soil as they are easy growing food plants known to take up PTMs. Research mostly focused on primary consumers, with Coleoptera being the most investigated arthropod order, probably because of the diversity of the order and its common occurrence worldwide. Most research was conducted in Europe, while South America and Africa only contributed 6.8% and 2.6%, respectively. The majority of the investigated articles (61%) assessed trophic transfer. From those, only 24% directly measured PTM transfer with experimental trials and included only one trophic level, that is, primary consumers, while 7% of research directly measured PTM transfer across multiple trophic levels (primary and secondary consumers). [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTY STATEMENTThe soil pollution caused with accretion of pollutant elements like lead (Pb) is the major environmental concern nowadays. Phytoremediation of contaminated soils using Brassica cultivars that act as hyperaccumulator plants for Pb emerges as an important technique for decontamination of Pb spiked soils. Therefore, pot study was carried out to compare the efficiency of three Brassica cultivars and select the most efficient cultivar for phytoremediation of Pb spiked soils. The experimental soil was contaminated with Pb applied @ 0, 125, 250, 500, 750, and 1,000 mg kg−1 soil. Our outcomes reflected that increased rates of Pb pollution in soil from 125 to 1,000 mg kg−1 soil resulted in decline of yield but enhanced the Pb acquisition of all Brassica cultivars. Comparison of cultivars indicated the highest biomass production (16.7 g pot−1), Pb acquisition (4,011.7 μg pot−1), contamination indices i.e., tolerance index (70.6), and bioaccumulation coefficient (17.03) by Brassica juncea produced thereby proving it as the most efficient cultivar for phytoremediation of Pb spiked soil.Consumption of crops raised in Pb spiked soil resulted in impaired health of human beings through its entrance into the food chain. Choice of techniques for decontamination of Pb polluted soils poses a great challenge worldwide. Among different techniques phytoremediation i.e., use of hyper accumulator crops is the most economical and ecological approach for the decontamination of Pb spiked soils. Therefore, this study was conducted for evaluating the comparative efficacy of three Brassica cultivars for their Pb accumulation potential and pollution indices and select the most efficient cultivar for phytoremediation of Pb spiked soils. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Location Methods Results Main Conclusions In complex networks, the degree distribution varies and provides an insight into the general structure of the system. For example, it may show scale‐free characteristics of the network, indicating higher vulnerability against non‐random disturbances. However, investigating its spatio‐temporal variability, degree distribution in marine food webs remains an unresolved issue. In this paper, we focus on describing the global variability of degree distribution in marine food webs.Global.We studied 105 marine food webs. By Kolmogorov–Smirnov test, and kernel density estimation, we determined the degree distribution of each food web, described its spatio‐temporal pattern and quantified the correlation between relevant parameters as a function of the scale‐free property of the degree distribution.Marine food webs around the globe did not strictly exhibit scale‐free characteristics in most regions, and only below 5% of the food webs entered the “strongest fit” level of the scale‐free network. We also find food webs in the polar regions indicate relatively high goodness‐of‐fit to scale‐free networks. The upwelling ecosystem related to ocean currents is prone to form a scale‐free web, which exhibits periodic scale‐free characteristics. The ecosystem types with relatively ‘low fit’ levels were mainly concentrated in the ecosystems heavily influenced by human activities.This research will enhance the research in terms of (a) classifying degree distribution in marine food webs; (b) revealing the variability in the spatial pattern of particular distributions, for example, the scale‐free characteristics and (c) exploring the distribution of in‐degree in space, quantifying the proportion of generalist and specialist species, as a potential indicator of adaptive potential of ecosystems. This research contributes to our understanding of the scale‐free features of marine food webs globally. It also offers a real systems‐based conservation approach to assess the spatial heterogeneity of the structural vulnerability of marine ecosystems. [ABSTRACT FROM AUTHOR]

There are two contrasting hypotheses regarding the drivers of biomass‐distribution among trophic levels within ecosystems. Energetic or bottom–up models propose control by supply of energy, either from autotrophy or from the underlying trophic level. Dynamical or top–down models propose control by predators in the overlying trophic level. Although multiple approaches have been used to reconcile these hypotheses, they have rarely considered the evolutionary pressures created by different distributions of biomass. Here, we study the effects of these evolutionary processes using an agent‐based, spatially‐explicit, eco‐evolutionary model. We demonstrate that, when ecosystems are simple and predator–prey relationships between species are fixed and do not evolve, primary productivity limits the number of trophic levels. In this case, the abundance in the top trophic level is always limited by productivity. However, productivity‐limited trophic levels subject those below them to limitation by predation, and predation‐limited trophic levels allow trophic levels below them to grow until limited by productivity. These results match the expectations of the exploitation ecosystems hypothesis (EEH), which predicts the same pattern of alternating top–down and bottom–up control on trophic levels. When species are able to evolve to adaptively adjust their trophic levels, however, selection is liable to lead to collapse of the trophic pyramid through prey switching. Under these conditions, all trophic levels experience bottom–up control. When the evolution of prey switching is restricted, higher trophic levels are evolutionarily stable and the predictions of the EEH are once again met; the stability of long food chains is thus dependent on the difficulty associated with prey switching. These results suggest that, at least under the combinations of model parameters explored in this study, evolutionary limitation is key to maintaining trophic structure. [ABSTRACT FROM AUTHOR]

Environmental changes reshape biological communities, inducing cascading effects throughout the food webs. These changes pressure species either to adapt or to track favorable habitats. Estuaries represent an interesting case study to investigate such responses as species will rapidly reach physical boundaries if they cannot adapt fast enough and need to track suitable conditions. One such estuary is the Baltic Sea, characterized by a salinity and temperature gradient that shapes species distribution and imposes physiological stress on organisms. The Baltic Sea is projected to be affected by substantial modifications in environmental conditions by the end of the 21st century, which could have major consequences for species distribution and community composition. However, despite the impending changes and their potential impact, there is a gap in understanding the potential consequences on pelagic species of the Baltic Sea. This study employs long‐term observations of primary zooplankton species in the pelagic food web to model changes in their distribution under future climate projections. We found that the parameters having the largest influence on habitat suitability varied across species, although maximal temperature was the most important for six out of seven species. In addition, there was a shrinkage of suitable area for several key species driven by a decrease in salinity and a rise in water temperature. We discuss the complex interplay between environmental changes and the spatial distribution of pelagic species in the Baltic Sea, highlighting the need for proactive management strategies to mitigate potential ecological impacts in the face of future climate scenarios. [ABSTRACT FROM AUTHOR]

To better identify the responses of phytoplankton blooms to warming conditions as expected in a climate change context, an in situ mesocosm experiment was carried out in a coastal Mediterranean lagoon (Thau Lagoon, South of France) in April 2018. Our objective was to assess both the direct and indirect effects of warming on phytoplankton, particularly those mediated by top-down control. Four treatments were applied: 1) natural planktonic community with ambient water temperature (C); 2) natural planktonic community at +3°C elevated temperature (T); 3) exclusion of larger zooplankton (> 200 μm; mesozooplankton) leaving microzooplankton predominant with ambient water temperature (MicroZ); and 4) exclusion of larger zooplankton (> 200 μm; mesozooplankton) at +3°C elevated temperature (TMicroZ). Warming strongly depressed the amplitude of the phytoplankton bloom as the chlorophyll a concentration was twice lower in the T treatment. This decline under warmer conditions was most likely imputed to increase top-down control by zooplankton. However, removal of mesozooplankton resulted in an opposite trend, with a higher bloom amplitude observed under warmer conditions (MicroZ vs. TMicroZ) pointing at a strong interplay between micro- and mesozooplankton and the effect of warming for the spring phytoplankton blooms. Furthermore, both warming and mesozooplankton exclusion induced shifts in phytoplankton community composition during bloom and post-bloom periods, favoring dinoflagellates and small green algae at the expense of diatoms and prymnesiophytes. Moreover, warming altered phytoplankton succession by promoting an early bloom of small green flagellates, and a late bloom of diatoms. Our findings clearly highlighted the sensitivity of phytoplankton blooms amplitudes, community composition and succession patterns to temperature increases, as well as the key role of initial zooplankton community composition to elicit opposite response in bloom dynamics. It also points out that warmer conditions might favor dinoflagellates and small green algae, irrespective of zooplankton community composition, with potential implications for food web dynamics and energy transfer efficiency under future ocean condition. [ABSTRACT FROM AUTHOR]

Amphibians are among the most endangered taxa worldwide, but little is known about how their disappearance can alter the functioning and structure of freshwater ecosystems, where they live as larval stages. This is particularly true for urodeles, which often are key predators in these ecosystems. The fire salamander (Salamandra salamandra) is a common predator in European fresh waters, but the species is declining due to habitat loss and the infection by fungal pathogens. We studied the consequences of fire salamander loss from three montane streams, by comparing two key ecosystem processes (periphyton accrual and leaf litter decomposition) and the structure of three communities (periphytic algae, aquatic hyphomycetes and invertebrates) using stream enclosures with and without salamander larvae. Salamander loss did not cause changes in invertebrate abundance or community structure, except for one stream where abundance increased in the absence of salamander larvae. However, salamander loss led to lower periphyton accrual, changes in algal community structure and slower leaf litter decomposition, with no associated changes in fungal communities or microbial decomposition. The changes observed may have been caused by release of salamander predatory pressure on invertebrates, which could have promoted their grazing on periphyton, in contrast to their preference for leaf shredding in the presence of salamander. Our study demonstrates an important role of salamander larvae in montane streams through top‐down control of lower trophic levels and thus in regulating key stream ecosystem processes. Our results highlight the need for improving protection measures for amphibians to prevent these alterations on ecosystem structure and function. [ABSTRACT FROM AUTHOR]

Anticoagulant rodenticides (ARs) are an effective tool used to suppress rodent populations in urban and agricultural settings to reduce human disease risk and economic loss, but widespread use has resulted in adverse effects on predators globally. Attention has largely been focused on impacts of ARs on raptors, although there is increasing evidence that mammalian carnivores are also impacted. We conducted a literature review to assess the extent to which ARs have been documented in wild mammalian carnivores globally and identify potential overlap with imperiled carnivores. We found a small but growing body of literature documenting exposure to ARs in 8 Carnivora families, with Mustelidae (64% of studies), Canidae (44%) and Felidae (23%) most represented. At least 11 different AR compounds were documented in carnivores, and authors claimed that exposure caused mortality of at least one individual in 33.9% of species studied. ARs were listed as a threat for 2% of Red List carnivores, although we found that 19% of Red List carnivores had ranges that overlap countries that have documented AR exposure in carnivores. Collectively, our review highlights the need to prioritize conservation attention on the potential role of ARs on global carnivore declines. We suggest (1) expanding AR monitoring and research outside of the northern hemisphere, (2) supporting long‐term AR monitoring to understand the spatial and temporal variation of AR use and exposure risk, (3) expanding research across trophic levels and across the urban–wildland gradient and 4) research to further our understanding of the point at which morbidity and mortality occur. [ABSTRACT FROM AUTHOR]

Arctic freshwater ecosystems are on the "frontline" of climate change, but due to a lack of direct long‐term monitoring data, indirect approaches, such as algal‐based paleolimnology, must be used to reconstruct past limnological conditions. Our understanding of the responses of small‐ to mid‐sized Arctic lakes to climate warming has increased over the last ~30 years. However, until recently, little was known about even the basic limnological conditions of Canada's "Northern Great Lakes," such as Lake Hazen, Great Bear Lake, and Great Slave Lake. In this summary, we show that a continuum of algal changes, observable in the sedimentary archives of shallow ponds to very large Arctic lakes, signals the crossing of key aquatic thresholds linked to changing ice covers and thermal regimes, declining wind speeds, and other climate‐related variables. With recent accelerated warming, even the largest and most resilient Arctic waterbodies are now fundamentally different than they were just a few decades ago. These changes will undoubtedly cascade throughout the food web leading to important changes for local Indigenous populations as well as the global community. [ABSTRACT FROM AUTHOR]

Estuaries exhibit high physicochemical variability and the properties of estuaries and the constituent segments are not yet systematically understood. This study aims to reveal the spatial heterogeneity of predominant organic sources using carbon and nitrogen stable isotope ratios (δ13C and δ15N, respectively) of Japanese eels (Anguilla japonica), one of the ideal natural samplers. In the Miyakoda River, Japan, our study site, the effectiveness of eel δ13C and δ15N values as standard indices of predominant organic sources was tested by employing the River Continuum Concept. This study then extended the application of these indices to the estuary, i.e., the Hamana Lake system, into which the Miyakoda River flows. Once in the upper estuary, eel δ13C and δ15N values became high, with the latter peaking in this river-estuary continuum, indicating that artificial labile subsidies (nutrients and organic matter) with high δ15N values were rapidly assimilated into the food web. Eel δ15N values decreased again in the middle estuary. Nevertheless, the influence of terrestrial organic subsidies extended into this segment, as evidenced by the low δ13C values of eels. These results suggest that refractory organic matter with low δ15N values, such as plant-derived ones, is slowly assimilated into the food web in the downstream estuarine segments. The higher δ13C values in the lower estuary suggested that the contribution of eelgrass or macroalgae occurred in addition to benthic microalgae. Thus, our results emphasize the need to consider the multiple energy flows to understand the estuary as a continuum. [ABSTRACT FROM AUTHOR]

Small pelagic fish (SPF) are crucial in marine food webs, transferring energy from plankton to higher trophic levels. This study focuses on herring (Clupea harengus) and sprat (Sprattus sprattus), addressing knowledge gaps in their feeding ecology in a nursery area, the Dutch Wadden Sea. We conducted a year-long, monthly survey, and used DNA metabarcoding to analyse zooplankton samples and stomach contents of two size classes of herring and sprat. Intra-, interspecific, and seasonal variations in fish condition, stomach fullness, and diet composition, along with selective feeding, were studied. Our study showed that condition and diet composition of herring and sprat, along with zooplankton density, exhibited a clear seasonal pattern. Juvenile herring and sprat displayed opportunistic feeding behaviour, rather than showing distinct prey selection. Besides copepods, we regularly observed (larvae of) benthic invertebrates in their diet. This emphasizes the crucial role of SPF as energy transfer agents, not solely between trophic levels, but also from benthic to pelagic habitats. Furthermore, fish post-larvae were part of the diet of larger herring (10–15 cm). Because of its unprecedented temporal and taxonomical detail, this study advances the understanding of seasonal dynamics of dominant components at the base of the Wadden Sea food web. [ABSTRACT FROM AUTHOR]

Seabird reproductive success in northern latitudes is often linked with prey abundance, availability, size, or species. Causes are often broadly explained as changes in ocean currents/temperatures, or diets. Few studies trace diets down the food web to primary producers, thus missing what I propose as an underlying cause of seabird colony failure, dietary abundance of essential omega-3 polyunsaturated fatty acids (PUFA). PUFA differ from other nutrients because they are, in part, ligands—critical for reproduction and other physiological processes for the entire marine food web, not just for seabirds. Diatoms are one of the few life forms that can produce PUFA de novo , and a lack of PUFA in zooplankton and fish reduces their abundance and productivity, with consequences up the food web. Since the mid-1980s, historical prey of breeding seabirds has decreased, and frequency of colony failures has increased. In years of failure, prey often had less fat than historically preferred species. Likewise, proportions of alternate species' PUFA, from published papers, show lower values than in historical prey. Production of PUFA by diatoms is depressed in warmer and more acidic environments, and I hypothesize that these warmer and more acidic seas have affected production of PUFA over the past 3–4 decades. Assuming this is true, I propose that these lower amounts of PUFA have negatively impacted the breeding success of all members of the marine food web, not just seabirds. [ABSTRACT FROM AUTHOR]

Mesozooplankton is a key component of the ocean, regulating global processes such as the carbon pump, and ensuring energy transfer from lower to higher trophic levels. Yet, knowledge on mesozooplankton diversity, distribution and connectivity at global scale is still fragmented. To fill this gap, we applied DNA metabarcoding to mesozooplankton samples collected during the Malaspina‐2010 circumnavigation expedition across the Atlantic, Indian and Pacific oceans from the surface to bathypelagic depths. We highlight the still scarce knowledge on global mesozooplankton diversity and identify the Indian Ocean and the deep sea as the oceanic regions with the highest proportion of hidden diversity. We report no consistent alpha‐diversity patterns for mesozooplankton at a global scale, neither across vertical nor horizontal gradients. However, beta‐diversity analysis suggests horizontal and vertical structuring of mesozooplankton communities mostly attributed to turnover and reveals an increase in mesozooplankton beta‐diversity with depth, indicating reduced connectivity at deeper layers. Additionally, we identify a water mass type‐mediated structuring of mesozooplankton bathypelagic communities instead of an oceanic basin‐mediated as observed at upper layers. This suggests limited dispersal at deep ocean layers, most likely due to weaker currents and lower mixing of water mass types, thus reinforcing the importance of oceanic currents and barriers to dispersal in shaping global plankton communities. [ABSTRACT FROM AUTHOR]

Simple Summary: Clingfish are small fish species that spend most of their time hiding in various shelters on the seabed. Due to this way of life, their ecology is little known, although they are important for the ecosystem. The aim of the research was to investigate the diet of three clingfish species (Lepadogaster lepadogaster, L. candolii, and Apletodon incognitus) using a method based on the analysis of prey from their faeces. The results show that crustaceans are the most important prey for all three species, although the composition of the diet also depends on various factors, such as the size of the fish and the prey, the behaviour of the fish, the home range of the fish, and the availability of food. These results provide us with important information about the participation of clingfish in the food web and deepen our knowledge of the fish's diet and the factors that influence it. The results also show that the occurrence of predatory fish depends on the presence of their prey. Cryptobenthic fish are small benthic fish species that normally live in various hiding places. Due to their large numbers, they are very important for energy transfer to higher trophic levels. However, due to their small size and hidden lifestyle, knowledge about them and their ecology, including their diet, is still limited. Using a non-destructive method based on faecal pellets, we investigated the diet of three clingfish species, Lepadogaster lepadogaster, L. candolii, and Apletodon incognitus, in the shallow northern Adriatic Sea. To better understand the results, we studied the fauna of potential prey in the habitats of the fish studied and also took fish specimens to observe their behaviour in the laboratory. The three species feed predominantly on crustaceans, particularly amphipods, copepods, and decapods. The proportion of the different taxa in the diet depends on the species of clingfish, the size of the specimens, and the size of the prey. In addition, the behaviour of the fish, the home range of the specimens, and the availability of food played an important role. The presence of certain crustacean groups in the environment also determines the occurrence of clingfish of different species and sizes. [ABSTRACT FROM AUTHOR]

We report the spatiotemporal increase in abundance of Anchoviella spp. (Engraulidae) through the diet of fish consumers after reservoir formation in the upper Tocantins River, Central Brazil. The increase in the abundance of this planktivorous fish evidences the growing importance of autochthonous herbivory food chains as the reservoir stabilized in this novel lentic ecosystem. These changes would otherwise remain unnoticed only through fish sampling, highlighting the importance of assessing trophic interactions to understand responses to damming at the community and ecosystem levels. [ABSTRACT FROM AUTHOR]

Clarifying the effects of biodiversity on ecosystem stability in the context of global environmental change is crucial for maintaining ecosystem functions and services. Asynchronous changes between trophic levels over time (i.e. trophic community asynchrony) are expected to increase trophic mismatch and alter trophic interactions, which may consequently alter ecosystem stability. However, previous studies have often highlighted the stabilising mechanism of population asynchrony within a single trophic level, while rarely examining the mechanism of trophic community asynchrony between consumers and their food resources.In this study, we analysed the effects of population asynchrony within and between trophic levels on community stability under the disturbances of climate warming, fishery decline and de‐eutrophication, based on an 18‐year monthly monitoring dataset of 137 phytoplankton and 91 zooplankton in a subtropical lake.Our results showed that species diversity promoted community stability mainly by increasing population asynchrony both for phytoplankton and zooplankton. Trophic community asynchrony had a significant negative effect on zooplankton community stability rather than that of phytoplankton, which supports the match‐mismatch hypothesis that trophic mismatch has negative effects on consumers. Furthermore, the results of the structural equation models showed that warming and top‐down effects may simultaneously alter community stability through population dynamics processes within and between trophic levels, whereas nutrients act on community stability mainly through the processes within trophic levels. Moreover, we found that rising water temperature decreased trophic community asynchrony, which may challenge the prevailing idea that climate warming increases the trophic mismatch between primary producers and consumers.Overall, our study provides the first evidence that population and trophic community asynchrony have contrasting effects on consumer community stability, which offers a valuable insight for addressing global environmental change. [ABSTRACT FROM AUTHOR]

Host populations often vary in the magnitude of coinfection they experience across environmental gradients. Furthermore, coinfection often occurs sequentially, with a second parasite infecting the host after the first has established a primary infection. Because the local environment and interactions between coinfecting parasites can both drive patterns of coinfection, it is important to disentangle the relative contributions of environmental factors and within‐host interactions to patterns of coinfection.Here, we develop a conceptual framework and present an empirical case study to disentangle these facets of coinfection. Across multiple lakes, we surveyed populations of five damselfly (host) species and quantified primary parasitism by aquatic, ectoparasitic water mites and secondary parasitism by terrestrial, endoparasitic gregarines. We first asked if coinfection is predicted by abiotic and biotic factors within the local environment, finding that the probability of coinfection decreased for all host species as pH increased. We then asked if primary infection by aquatic water mites mediated the relationship between pH and secondary infection by terrestrial gregarines.Contrary to our expectations, we found no evidence for a water mite‐mediated relationship between pH and gregarines. Instead, the intensity of gregarine infection correlated solely with the local environment, with the magnitude and direction of these relationships varying among environmental predictors.Our findings emphasize the role of the local environment in shaping infection dynamics that set the stage for coinfection. Although we did not detect within‐host interactions, the approach herein can be applied to other systems to elucidate the nature of interactions between hosts and coinfecting parasites within complex ecological communities. [ABSTRACT FROM AUTHOR]

Arthropods play a vital role in ecosystems; yet, their distributions remain poorly understood, particularly in mountainous regions.This study delves into the modelling of the distribution of 31 foliar arthropod genera in the French Alps, using a comprehensive approach encompassing multi‐trophic sampling, community DNA metabarcoding and random forest models.The results underscore the significant importance of vegetation structure, such as herbaceous vegetation density, and forest density and heterogeneity, along with climate, in shaping the distributions of most arthropods. These responses to environmental gradients are consistent across trophic groups, with the exception of nectarivores, whose distributions are more sensitive to landscape structure and water availability.By leveraging community DNA metabarcoding, this study sheds light on the understudied drivers of arthropod distributions, emphasizing the importance of modelling across diverse trophic groups to anticipate arthropod responses to global change. [ABSTRACT FROM AUTHOR]

ABSTRACT Fishery discards worldwide increase the availability of organic materials on the benthos, altering trophic relationships and potentially increasing the abundance of benthic consumers. Expert knowledge from fishers is a valuable yet often underutilized source of information to understand these dynamics. We interviewed Dungeness crab fishers (n = 24) to determine the most‐used bait types and to characterize regional and seasonal bait use strategies that drive inputs of organic matter into Oregon coastal waters during the commercial Dungeness crab fishery each year. Based on bomb calorimetry measurements of caloric densities of 12 commonly reported bait species, total energetic input was 12.99 × 109 kJ (3.10 B kcal) from bait in the 2019–2020 commercial ocean Dungeness season in Oregon, USA. Fishing effort and bait inputs were strongly seasonal, with 88% of effort concentrated in the first 60 days of the 9‐month‐long season but did not vary regionally. This large, temporally concentrated caloric input suggested that bait could contribute substantially to Dungeness crab productivity. Fisher respondents indicated that bait effectiveness was the most important motivating factor in choosing a bait type, more than availability or cost. [ABSTRACT FROM AUTHOR]

Summary: The blue crab is one of the most invasive alien species in the Mediterranean Sea. Its remarkable surge in availability suggests an imminent increase in consumption. However, blue crabs are vulnerable to contamination by per‐ and polyfluoroalkyl substances (PFAS), known to accumulate in the food chain and pose health risks to humans. Data on PFAS contamination levels in blue crabs are a few. This study investigates 26 PFAS in 113 blue crabs by UHPLC‐HRMS. Results revealed higher concentrations in cephalothorax than in claws. PFHpA, PFHxS, PFOA, PFNA, PFOS, PFUnDA, PFDoDA, PFTrDA, PFHpS, and PFBA were among the most detected PFAS. Total PFAS mean concentration ranged from 0.65 to 2.61 ng g−1 ww. Three crabs exceeded maximum residue limits for PFOA, PFNA, and PFHxS. Statistical analyses suggested a correlation between contaminants presence and crab size. PCA highlighted the weight as a potential predictor of PFOS concentration. PFAS intake evaluation showed no risk for consumers. [ABSTRACT FROM AUTHOR]

The landscape theory of food web architecture (LTFWA) describes relationships among body size, trophic position, mobility, and energy channels that serve to couple heterogenous habitats, which in turn promotes long‐term system stability. However, empirical tests of the LTFWA are rare and support differs among terrestrial, freshwater, and marine systems. Further, it is unclear whether the theory applies in highly altered ecosystems dominated by introduced species such as the Laurentian Great Lakes. Here, we provide an empirical test of the LTFWA by relating body size, trophic position, and the coupling of different energy channels using stable isotope data from species throughout the Lake Michigan food web. We found that body size was positively related to trophic position, but for a given trophic position, organisms predominately supported by pelagic energy had smaller body sizes than organisms predominately supported by nearshore benthic energy. We also found a hump‐shaped trophic relationship in the food web where there is a gradual increase in the coupling of pelagic and nearshore energy channels with larger body sizes as well as higher trophic positions. This highlights the important role of body size and connectivity among habitats in structuring food webs. However, important deviations from expectations are suggestive of how species introductions and other anthropogenic impacts can affect food web structure in large lakes. First, native top predators appear to be flexible couplers that may provide food web resilience, whereas introduced top predators may confer less stability when they specialize on a single energy pathway. Second, some smaller bodied prey fish and invertebrates, in addition to mobile predators, coupled energy from pelagic and nearshore energy channels, which suggests that some prey species may also be important integrators of energy pathways in the system. We conclude that patterns predicted by the LTFWA are present in the face of species introductions and other anthropogenic stressors to a degree, but time‐series evaluations are needed to fully understand the mechanisms that promote stability. [ABSTRACT FROM AUTHOR]

Space use by small mammals should mirror their immediate needs for food and predator shelters but can also be influenced by seasonal changes in biotic and abiotic factors. Lemmings are keystone species of the tundra food web, but information on their spatial distribution in relation to habitat heterogeneity is still scant, especially at a fine scale. In this study, we used spatially explicit capture–recapture methods to determine how topography, hydrology, vegetation, and soil characteristics influence the fine-scale spatial variations in summer density of brown lemmings (Lemmus trimucronatus). Lemmings were monitored throughout the summer in wet and mesic tundra habitats and in a predator exclusion grid, which was also located in mesic tundra. We found that in wet tundra, lemming densities were higher at sites with a rugged topography dominated by hummocks, but only during snow melt. In both mesic tundra sites, lemming densities were higher in sites with poor drainage and low aspect throughout the summer. We found no clear association between lemming densities and any tested vegetation or soil variables. Overall, hydrology and topography appear to play a dominant role in small-scale space use of brown lemmings with a secondary role for predator avoidance and food plant abundance. [ABSTRACT FROM AUTHOR]

The interconnectedness of adjacent freshwater and terrestrial ecosystems results in ‘tangled‐webs’, where the cross‐boundary exchange of materials results in energy flows that provide critical resources for ecosystem productivity. However, these energy flows can be disrupted by anthropogenic activities, resulting in modified ecosystem functioning. A ubiquitous anthropogenic activity in fresh waters is recreational angling. Five major angling activities can disrupt the structure of the ‘tangled‐web’ to produce an ‘angled‐web’ (a tangled food web that is modified by angling activities). (1) Fish stocking increases the number and species available to exploit, but the increased fish abundances can have strong top‐down effects and disrupt reciprocal prey subsidies. Following capture, fish are either (2) harvested or (3) released alive (‘catch‐and‐release0’); both can both drive eco‐evolutionary changes that can modify food‐web structure. Where fish are exploited using baited hooks, (4) the release of ‘ground‐bait’ is used as a fish attractant; its composition of novel protein and carbohydrate sources form novel trophic links in the food web and can accelerate eutrophication. Some angling styles also require (5) riparian and in‐stream vegetation to be cleared to minimise gear fouling, potentially modifying fish spawning and nursery areas. We suggest that each of these angling impacts (and their interactions) can contribute to transforming the ‘tangled web’ into an ‘angled‐web’, with the strength and direction of the transformation dependent on angling pressure, prevailing fishery practices, regulations and management, and the extent of the interaction effects of the activities. These interactions and their impacts will vary globally given angling methods, practices and regulations differ across the world. We argue that, in this era of substantial environmental change driven by climate change, habitat loss and nutrient enrichment of fresh waters, the extent to which angling impacts food webs should not be overlooked and underappreciated. We emphasise that when freshwater angling activities are poorly managed and/or unregulated, they can strongly modify the interconnectedness between terrestrial and freshwater food webs. [ABSTRACT FROM AUTHOR]

Processed plant-based foods, particularly high carbohydrate-containing foods, are among the greatest contributors to dietary acrylamide, a probable human carcinogen, uptake. Between 2009 and 2020, five surveys were conducted to determine acrylamide in high carbohydrate-containing foods in Canada. These surveys included sampling of potato and sweet potato chips, French fries, and frozen potato/sweet potato products, as a follow-up to our earlier surveys from 2002 - 2008. Samples were analyzed using isotope dilution (13C3-acrylamide) with LC-MS/MS. The highest mean acrylamide levels were found in sweet potato chips. Among potato chips (57 to 4660 ng g−1), one brand consistently showed the highest concentrations with wide variability. Acrylamide concentrations decreased over time in ready-to-eat French fries (from 480 to 358 ng g−1), and one brand showed a clear reduction temporally. Wide variations were observed among brands, among lots/outlets of same brands, and among different food chains. Acrylamide levels in potato chips decreased between 2009 and 2016 (504.3 ng g−1) relative to the period 2002 - 2008 (1096.9 ng g−1). The acrylamide trends observed in the products measured in the latest study indicate that food producers may have adopted mitigation strategies. [ABSTRACT FROM AUTHOR]

The bottom ash produced during incineration contains toxic heavy metals that can persist for a long time in the environment and accumulate in the food chain; when indiscriminately disposed of, it can adversely affect public health. The study aimed at assessing the level of heavy metals in the bottom ashes produced during the incineration of sharp medical waste. Bottom ash samples were collected from the ash pit of the incinerator twice a month for four months (two months in the rainy and two months in the dry season) in triplicates. Five grams of the sieved samples were analyzed for cadmium (Cd), chromium (Cr), Nickel (Ni), iron (Fe), lead (Pb), Copper (Cu), and zinc (Zn) using atomic absorption spectrophotometer. The mean concentrations of these heavy metals during the study period in decreasing order were Fe (18,504.66) > Zn (16,292.11) > Cr (374.47) > Pb (179.78) > Cu (128.91) > Cd (1.28) > Ni (0.50) mg/kg. The concentrations of the assessed heavy metals in the bottom ash samples obtained were compared with notable international guidelines, and it was deduced that the concentrations of all the heavy metals were above the acceptable limits except for Nickel, whose concentration was below the limit set for it. [ABSTRACT FROM AUTHOR]

Fires are becoming increasingly frequent, intense, severe and prolonged worldwide, and such situation is worsening. As a result, extreme fire conditions will increase, with consequences for wildlife, including increased mass mortality and changes in trophic relationships in natural communities. This intensification is expected to be particularly pronounced in the Mediterranean ecosystems. In this scoping review, we summarized current knowledge and gaps in understanding the effects of fires on wildlife, focusing on predator–prey interactions. These interactions play a critical role in animal communities and their understanding is fundamental for appropriate management and conservation. Mammals were chosen as a model group because of their remarkable ecological role. We grouped and analysed the post-wildfire changes in the predator–prey relationships into three-time intervals: immediate, short- and long-term effects. This is relevant as vegetation restoration, by altering cover and habitat structure, may affect hunting strategies and anti-predatory behaviour. Our review showed that studies generally had several limitations, the most common of which were the lack of replication, the strong geographical bias, and the focus on few target species. Nevertheless, we could formally describe how fire affects predator–prey relationships in Mediterranean ecosystems through processes that exert different cascading effects at different times after the fire event. We encourage long-term studies on communities, including as many components of the food chain as possible, using an interdisciplinary approach, and prioritising investigations in high-risk ecosystems. [ABSTRACT FROM AUTHOR]

The separation of macro-level and microbial food webs is typical but has important limits. A multilayered food web conceptual model is needed because microbial food webs are nested within macro-organisms. These multilayered microbial food webs likely influence the network dynamics of macro-level food webs. A multilayered food webs model opens new avenues for empirical investigations into the complexity of ecological networks. The model can provide a new lens through which to view a network's response to ecosystem changes. Food webs are typically defined as being macro-organism-based (e.g., plants, mammals, birds) or microbial (e.g., bacteria, fungi, viruses). However, these characterizations have limits. We propose a multilayered food web conceptual model where microbial food webs are nested within food webs composed of macro-organisms. Nesting occurs through host–microbe interactions, which influence the health and behavior of host macro-organisms, such that host microbiomes likely alter population dynamics of interacting macro-organisms and vice versa. Here, we explore the theoretical underpinnings of multilayered food webs and the implications of this new conceptual model on food web ecology. Our framework opens avenues for new empirical investigations into complex ecological networks and provides a new lens through which to view a network's response to ecosystem changes. [ABSTRACT FROM AUTHOR]

The composition of fatty acids in the muscle tissue of the unique Central Asian carp-like fish, Potanin Altai osman Oreoleuciscus potanini, was studied for the first time. The populations of these fish in the reservoirs of the semiarid zone (Durgun and Taishir) during the period of their formation are considered. It was shown that the content of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in O. potanini corresponds to the median of this value in the order Cypriniformes. It was established that the basis of the food web of the herbivorous form of this species consists of microalgae (diatoms, Euglena and, possibly, chrysophytes), as well as bacteria. At the same time, the levels of bacterial biomarkers, 15-17BCFA and 17:0 were significantly higher in fish in the Durgun reservoir, whereas the level of EPA (diatom biomarker) in O. potanini was higher in the Taishir reservoir. The established higher values of the heavy nitrogen isotope content in the muscles of O. potanini from the Taishir reservoir are most likely associated with the yet unformed benthic communities and with the incomplete diversification of the riverine form of the Potanin Altai osman into lacustrine forms. [ABSTRACT FROM AUTHOR]

Knowledge of biotic predator–prey interactions is essential for understanding the role of species in the food web; however, information on these interactions is scarce for most species. Our aim in this study was to gather information on the potential predators of two species of herpetofauna abundant in the rainforest they inhabit, the frog Craugastor loki and the snake Ninia sebae. For this, realistic models of the two species were placed, and monitored using camera traps, in 13 sites located in a forest fragment belonging to a private protected natural area in southern Veracruz in three seasons (dry, rainy and windy) in 2019. In addition, the temporality and seasonality of the events and some behaviours of the potential predators are described. The recorded events were classified into four categories: presence, interest, contact and aggression. For C. loki, 159 events of appearances of potential predators were identified (32 with interaction: 18 events of interest, 2 contact and 12 aggressions). The aggressions were carried out by the mammals Didelphis marsupialis and Peromyscus sp. In the case of N. sebae, 201 appearances of potential predators were identified (75 with interaction: 36 events of interest, 7 contact and 32 aggressions). The aggressions were carried out by 10 species (seven birds and three mammals). Bird predation events towards models of both species occurred during daytime while the attacks by mammals occurred at night. Agonistic behaviours included pecking, biting and urine marking, previously unknown. Events of each category were recorded every season. Our results indicate that C. loki and N. sebae may have more predators than were previously known, and suggest that these species can be an important food resource for different species of birds and mammals in the environments where they live. [ABSTRACT FROM AUTHOR]

Production of synthetic plastic obtained from fossil fuels are considered as a constantly growing problem and lack in the management of plastic waste has led to severe microplastic pollution in the aquatic ecosystem. Plastic particles less than 5mm are termed as microplastics (MPs), these are pervasive in water and soil, it can also withstand longer period of time with high durability. It can be broken down into smaller particles and can be adsorbed by various life-forms. Most marine organisms tend to consume plastic debris that can be accumulated easily into the vertebrates, invertebrates and planktonic entities. Often these plastic particles surpass the food chain, resulting in the damage of various organs and inhibiting the uptake of food due to the accumulation of microplastics. In this review, the physical and chemical properties of microplastics, as well as their effects on the environment and toxicity of their chemical constituents are discussed. In addition, the paper also sheds light on the potential of microorganisms such as bacteria, fungi, and algae which play a pivotal role in the process of microplastics degradation. The mechanism of microbial degradation, the factors that affect degradation, and the current advancements in genetic and metabolic engineering of microbes to promote degradation are also summarized. The paper also provides information on the bacterial, algal and fungal degradation mechanism including the possible enzymes involved in microplastic degradation. It also investigates the difficulties, limitations, and potential developments that may occur in the field of microbial microplastic degradation. [ABSTRACT FROM AUTHOR]

Due to its fundamental position in the aquatic food chain linking primary producers (phytoplankton) to higher trophic levels (fish), zooplankton has a crucial influence on the structure and function of lakes. The scientific literature shows that zooplankton is an effective indicator of eutrophication. However, according to the requirements of the Water Framework Directive, zooplankton is still not included as one of the biological components for assessing the ecological status of lakes. In Poland, the zooplankton-based method (ZIPLAs) has been developed to assess the ecological status of deep stratified lakes. Shallow lakes function differently from deep lakes, and literature data show that the response of zooplankton indices to eutrophication parameters is much weaker than in deep lakes. This paper presents the Zooplankton Index for Shallow Lakes' Assessment (ZISLA), a new method for assessing ecological status based on zooplankton community structure. The ZISLA includes the body size index of Daphnia cucullata (BSI), the percentage share of high trophy-indicating rotifer species (IHTROT), the number of rotifer species (NROT), and the Margalef index (D). The ZISLA shows a strong, significant correlation with total phosphorus and total nitrogen (Spearman's coefficient (R = −0.77, R = −0.74; p < 0.0001) and slightly weaker with Secchi disk visibility (R = 0.72; p < 0.0001). The ZISLA index shows a statistically significant good/moderate distinction for all water quality parameters. [ABSTRACT FROM AUTHOR]