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Studies of community assembly typically focus on the effects of abiotic environmental filters and stabilizing competition on functional trait dispersion within single trophic levels. Predation is a well-known driver of community diversity and composition, yet the role of functionally diverse predator communities in filtering prey community traits has received less attention. We examined functionally diverse communities of predators (fishes) and prey (epifaunal crustaceans) in eelgrass (Zostera marina) beds in two northern California estuaries to evaluate the filtering effects of predator traits on community assembly and how filters acting on predators influence their ability to mediate prey community assembly. Fish traits related to bottom orientation were correlated with more clustered epifauna communities, and epifauna were generally overdispersed while fishes were clustered, suggesting prey may be pushed to disparate areas of trait space to avoid capture by benthic sit-and-wait predators. We also found correlations between the trait dispersions of predator and prey communities that strengthened after accounting for the effects of habitat filters on predator dispersion, suggesting that habitat filtering effects on predator species pools may hinder their ability to affect prey community assembly. Our results present compelling observational evidence that specific predator traits have measurable impacts on the community assembly of prey, inviting experimental tests of predator trait means on community assembly and explicit comparisons of how the relative effects of habitat filters and intraguild competition on predators impact their ability to affect prey community assembly. Integrating our understanding of traits at multiple trophic levels can help us better predict the impacts of community composition on food web dynamics as regional species pools shift with climate change and anthropogenic introductions.

Harmful cyanobacteria blooms are a growing threat in estuarine waters as upstream blooms are exported into coastal environments. Cyanobacteria can produce potent toxins, one of which-hepatotoxic microcystins (MCs)-can persist and accumulate within the food web. Filter-feeding invertebrates may biomagnify toxins up to 100× ambient concentrations. As such, bivalves can be used as an environmentally relevant and highly sensitive sentinel for MC monitoring. To date there has been little research on cyanotoxin bioaccumulation in estuaries. The Sacramento-San Joaquin Delta (Delta) aquatic food web has undergone a profound change in response to widespread colonization of aquatic invasive species such as Asian clams (Corbicula fluminea) in the freshwater portion of the Delta. These clams are prolific-blanketing areas of the Delta at densities up to 1000 clams/m2 and are directly implicated in the pelagic organism decline of threatened and endangered fishes. We hypothesized that Asian clams accumulate MCs which may act as an additional stressor to the food web and MCs would seasonally be in exceedance of public health advisory levels. MCs accumulation in Delta Asian clams and signal crayfish (Pacifastacus leniusculus) were studied over a two-year period. ELISA and LC-MS analytical methods were used to measure free and protein-bound MCs in clam and crayfish tissues. We describe an improved MC extraction method for use when analyzing these taxa by LC-MS. MCs were found to accumulate in Asian clams across all months and at all study sites, with seasonal maxima occurring during the summer. Although MC concentrations rarely exceeded public health advisory levels, the persistence of MCs year-round still poses a chronic risk to consumers. Crayfish at times also accumulated high concentrations of MCs. Our results highlight the utility of shellfish as sentinel organisms for monitoring in estuarine areas.

The costs of foraging can be high while also carrying significant risks, especially for consumers feeding at the top of the food chain. To mitigate these risks, many predators supplement active hunting with scavenging and kleptoparasitic behaviours, in some cases specializing in these alternative modes of predation. The factors that drive differential utilization of these tactics from species to species are not well understood. Here, we use an energetics approach to investigate the survival advantages of hunting, scavenging and kleptoparasitism as a function of predator, prey and potential competitor body sizes for terrestrial mammalian carnivores. The results of our framework reveal that predator tactics become more diverse closer to starvation, while the deployment of scavenging and kleptoparasitism is strongly constrained by the ratio of predator to prey body size. Our model accurately predicts a behavioural transition away from hunting towards alternative modes of predation with increasing prey size for predators spanning an order of magnitude in body size, closely matching observational data across a range of species. We then show that this behavioural boundary follows an allometric power-law scaling relationship where the predator size scales with an exponent nearing 3/4 with prey size, meaning that this behavioural switch occurs at relatively larger threshold prey body size for larger carnivores. We suggest that our approach may provide a holistic framework for guiding future observational efforts exploring the diverse array of predator foraging behaviours.

Arbuscular mycorrhizal fungi (AMF) transport substantial plant carbon (C) that serves as a substrate for soil organisms, a precursor of soil organic matter (SOM), and a driver of soil microbial dynamics. Using two-chamber microcosms where an air gap isolated AMF from roots, we 13CO2-labeled Avena barbata for 6 wk and measured the C Rhizophagus intraradices transferred to SOM and hyphosphere microorganisms. NanoSIMS imaging revealed hyphae and roots had similar 13C enrichment. SOM density fractionation, 13C NMR, and IRMS showed AMF transferred 0.77 mg C g-1 of soil (increasing total C by 2% relative to non-mycorrhizal controls); 33% was found in occluded or mineral-associated pools. In the AMF hyphosphere, there was no overall change in community diversity but 36 bacterial ASVs significantly changed in relative abundance. With stable isotope probing (SIP)-enabled shotgun sequencing, we found taxa from the Solibacterales, Sphingobacteriales, Myxococcales, and Nitrososphaerales (ammonium oxidizing archaea) were highly enriched in AMF-imported 13C (> 20 atom%). Mapping sequences from 13C-SIP metagenomes to total ASVs showed at least 92 bacteria and archaea were significantly 13C-enriched. Our results illustrate the quantitative and ecological impact of hyphal C transport on the formation of potentially protective SOM pools and microbial roles in the AMF hyphosphere soil food web.

The allometric trophic network (ATN) framework for modeling population dynamics has provided numerous insights into ecosystem functioning in recent years. Herein we extend ATN modeling of the intertidal ecosystem off central Chile to include empirical data on pelagic chlorophyll-a concentration. This intertidal community requires subsidy of primary productivity to support its rich ecosystem. Previous work models this subsidy using a constant rate of phytoplankton input to the system. However, data shows pelagic subsidies exhibit highly variable, pulse-like behavior. The primary contribution of our work is incorporating this variable input into ATN modeling to simulate how this ecosystem may respond to pulses of pelagic phytoplankton. Our model results show that: (1) closely related sea snails respond differently to phytoplankton variability, which is explained by the underlying network structure of the food web; (2) increasing the rate of pelagic-intertidal mixing increases fluctuations in species biomasses that may increase the risk of local extirpation; (3) predators are the most sensitive species to phytoplankton biomass fluctuations, putting these species at greater risk of extirpation than others. Finally, our work provides a straightforward way to incorporate empirical, time-series data into the ATN framework that will expand this powerful methodology to new applications.

Ecosystems that are coupled by reciprocal flows of energy and nutrient subsidies can be viewed as a single "meta-ecosystem." Despite these connections, the reciprocal flow of subsidies is greatly asymmetrical and seasonally pulsed. Here, we synthesize existing literature on stream-riparian meta-ecosystems to quantify global patterns of the amount of subsidy consumption by organisms, known as "allochthony." These resource flows are important since they can comprise a large portion of consumer diets, but can be disrupted by human modification of streams and riparian zones. Despite asymmetrical subsidy flows, we found stream and riparian consumer allochthony to be equivalent. Although both fish and stream invertebrates rely on seasonally pulsed allochthonous resources, we find allochthony varies seasonally only for fish, being nearly three times greater during the summer and fall than during the winter and spring. We also find that consumer allochthony varies with feeding traits for aquatic invertebrates, fish, and terrestrial arthropods, but not for terrestrial vertebrates. Finally, we find that allochthony varies by climate for aquatic invertebrates, being nearly twice as great in arid climates than in tropical climates, but not for fish. These findings are critical to understanding the consequences of global change, as ecosystem connections are being increasingly disrupted.

Ecological communities can be stable over multiple generations, or rapidly shift into structurally and functionally different configurations. In kelp forest ecosystems, overgrazing by sea urchins can abruptly shift forests into alternative states that are void of macroalgae and primarily dominated by actively grazing sea urchins. Beginning in 2014, a sea urchin outbreak along the central coast of California resulted in a patchy mosaic of remnant forests interspersed with sea urchin barrens. In this study, we used a 14-year subtidal monitoring dataset of invertebrates, algae, and fishes to explore changes in community structure associated with the loss of forests. We found that the spatial mosaic of barrens and forests resulted in a region-wide shift in community structure. However, the magnitude of kelp forest loss and taxonomic-level consequences were spatially heterogeneous. Taxonomic diversity declined across the region, but there were no declines in richness for any group, suggesting compositional redistribution. Baseline ecological and environmental conditions, and sea urchin behaviour, explained the persistence of forests through multiple stressors. These results indicate that spatial heterogeneity in preexisting ecological and environmental conditions can explain patterns of community change.

Trait-based frameworks are increasingly used for predicting how ecological communities respond to ongoing global change. As species range shifts result in novel encounters between predators and prey, identifying prey guilds, based on a suite of shared traits, can distill complex species interactions, and aid in predicting food web dynamics. To support advances in trait-based research in open-ocean systems, we present the Pelagic Species Trait Database, an extensive resource documenting functional traits of 529 pelagic fish and invertebrate species in a single, open-source repository. We synthesized literature sources and online resources, conducted morphometric analysis of species images, as well as laboratory analyses of trawl-captured specimens to collate traits describing 1) habitat use and behavior, 2) morphology, 3) nutritional quality, and 4) population status information. Species in the dataset primarily inhabit the California Current system and broader NE Pacific Ocean, but also includes pelagic species known to be consumed by top ocean predators from other ocean basins. The aim of this dataset is to enhance the use of trait-based approaches in marine ecosystems and for predator populations worldwide.

Cross-ecosystem subsidies are critical to ecosystem structure and function, especially in recipient ecosystems where they are the primary source of organic matter to the food web. Subsidies are indicative of processes connecting ecosystems and can couple ecological dynamics across system boundaries. However, the degree to which such flows can induce cross-ecosystem cascades of spatial synchrony, the tendency for system fluctuations to be correlated across locations, is not well understood. Synchrony has destabilizing effects on ecosystems, adding to the importance of understanding spatiotemporal patterns of synchrony transmission. In order to understand whether and how spatial synchrony cascades across the marine-terrestrial boundary via resource subsidies, we studied the relationship between giant kelp forests on rocky nearshore reefs and sandy beach ecosystems that receive resource subsidies in the form of kelp wrack (detritus). We found that synchrony cascades from rocky reefs to sandy beaches, with spatiotemporal patterns mediated by fluctuations in live kelp biomass, wave action, and beach width. Moreover, wrack deposition synchronized local abundances of shorebirds that move among beaches seeking to forage on wrack-associated invertebrates, demonstrating that synchrony due to subsidies propagates across trophic levels in the recipient ecosystem. Synchronizing resource subsidies likely play an underappreciated role in the spatiotemporal structure, functioning, and stability of ecosystems.

Large-scale shifts in marine species biogeography have been a notable impact of climate change. An effective explanation of what drives these species shifts, as well as accurate predictions of where they might move, is crucial to effectively managing these natural resources and conserving biodiversity. While temperature has been implicated as a major driver of these shifts, physiological processes suggest that oxygen, prey, and other factors should also play important roles. We expanded upon previous temperature-based distribution models by testing whether oxygen, food web productivity, salinity, and scope for metabolic activity (the Metabolic Index) better explained the changing biogeography of Black Sea Bass (Centropristis striata) in the Northeast US. This species has been expanding further north over the past 15 years. We found that oxygen improved model performance beyond a simple consideration of temperature (ΔAIC = 799, ΔTSS = 0.015), with additional contributions from prey and salinity. However, the Metabolic Index did not substantially increase model performance relative to temperature and oxygen (ΔAIC = 0.63, ΔTSS = 0.0002). Marine species are sensitive to oxygen, and we encourage researchers to use ocean biogeochemical hindcast and forecast products to better understand marine biogeographic changes.

The Northern California Current is a highly productive marine upwelling ecosystem that is economically and ecologically important. It is home to both commercially harvested species and those that are federally listed under the U.S. Endangered Species Act. Recently, there has been a global shift from single-species fisheries management to ecosystem-based fisheries management, which acknowledges that more complex dynamics can reverberate through a food web. Here, we have integrated new research into an end-to-end ecosystem model (i.e., physics to fisheries) using data from long-term ocean surveys, phytoplankton satellite imagery paired with a vertically generalized production model, a recently assembled diet database, fishery catch information, species distribution models, and existing literature. This spatially-explicit model includes 90 living and detrital functional groups ranging from phytoplankton, krill, and forage fish to salmon, seabirds, and marine mammals, and nine fisheries that occur off the coast of Washington, Oregon, and Northern California. This model was updated from previous regional models to account for more recent changes in the Northern California Current (e.g., increases in market squid and some gelatinous zooplankton such as pyrosomes and salps), to expand the previous domain to increase the spatial resolution, to include data from previously unincorporated surveys, and to add improved characterization of endangered species, such as Chinook salmon (Oncorhynchus tshawytscha) and southern resident killer whales (Orcinus orca). Our model is mass-balanced, ecologically plausible, without extinctions, and stable over 150-year simulations. Ammonium and nitrate availability, total primary production rates, and model-derived phytoplankton time series are within realistic ranges. As we move towards holistic ecosystem-based fisheries management, we must continue to openly and collaboratively integrate our disparate datasets and collective knowledge to solve the intricate problems we face. As a tool for future research, we provide the data and code to use our ecosystem model.

Imagine the vast Palaeozoic oceans: graptolites (Pterobranchia, Graptolithina) appear as small and inconspicuous benthic faunal elements in the early Cambrian, later becoming one of the dominating planktic groups of macrofauna in Ordovician and Silurian marine environments. Their unusual organic housing secretions (tubaria) in the fossil record makes them one of the most important biostratigraphic markers for the Ordovician to early Devonian time intervals. The occurrence, especially of the planktic graptolites, in black shales led to the common notion of a life style that related them to anoxic or dysaerobic environments, but is merely a preservational aspect. Their demise in the early Devonian may be related to the origination and diversification of large plankton feeding organisms in the marine realm as the graptolites were unable to complete with the much faster growth and reproduction of smaller, non-colonial organisms that did not need to waste time producing a housing construction. Thus, from the later Devonian onwards, the graptolites were largely gone and the oceans were teeming with fast reproducing and growing micro-and macroplankton. Larger predatory animals evolved as plankton feeders, that may have preyed on the graptolites. Only a few cryptic benthic species survived into the modern world. [ABSTRACT FROM AUTHOR]

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Microplastics have been recently detected in many environmental media and living organisms, yet their transfer and toxicity to humans are poorly known. Here, we review microplastic transfer in the food chain with focus on microplastic pollution sources, methods to analyze microplastics in food, health impact of food-related microplastic exposure, and remediation of microplastic pollution. Microplastic pollution sources include seafood, food additives, packaging materials, and agricultural and industrial products. Remediation techniques comprise the use of microbial enzymes and biofilms. Microplastic detection methods in food rely on separation and quantification by optical detection, scanning electron micrography, and Fourier-transform infrared spectroscopy. Human health impact following microplastic ingestion include cancers, organ and respiration damage, and reproductive impairments. Overall, microplastic toxicity is mainly due to their ability to enter the metabolism, adsorption into the circulatory system for translocation, and difficulty, if not impossibility, of excretion. [ABSTRACT FROM AUTHOR]

Microorganisms, genetically modified or not, may be used in the food chain either as active agents, biomasses or as production organisms of substances of interest. The placement of such microorganisms or their derived substances/products in the European market may be subject to a premarket authorisation process. The authorisation process requires a risk assessment in order to establish the safety and/or the efficacy of the microorganism(s) when used in the food chain as such, as biomasses or as production strains. This includes a full molecular characterisation of the microorganism(s) under assessment. For certain regulated products, the use of whole genome sequence (WGS) data of the microorganism is established as a requirement for the risk assessment. In this regard, data obtained from WGS analysis can provide information on the unambiguous taxonomic identification of the strains, on the presence of genes of concern (e.g. those encoding virulence factors, resistance to antimicrobials of clinical relevance for humans and animals, production of harmful metabolites or of clinically relevant antimicrobials) and on the characterisation of genetic modification(s) (where relevant). This document provides recommendations to applicants on how to describe and report the results of WGS analyses in the context of an application for market authorisation of a regulated product. Indications are given on how to perform genome sequencing and the quality criteria/thresholds that should be reached, as well as the data and relevant information that need to be reported, if required. This updated document replaces the EFSA 2021 Statement and reflects the current knowledge in technologies and methodologies to be used to generate and analyse WGS data for the risk assessment of microorganisms. [ABSTRACT FROM AUTHOR]

Plastics are present in almost every aspect of our lives. Polyethylene terephthalate (PET) is commonly used in the food industry. Microparticles can contaminate food and drinks, posing a threat to consumers. The presented study aims to determine the effect of microparticles of PET on the population of neurons positive for selected neurotransmitters in the enteric nervous system of the jejunum and histological structure. An amount of 15 pigs were divided into three groups (control, receiving 0.1 g, and 1 g/day/animal orally). After 28 days, fragments of the jejunum were collected for immunofluorescence and histological examination. The obtained results show that histological changes (injury of the apical parts of the villi, accumulations of cellular debris and mucus, eosinophil infiltration, and hyperaemia) were more pronounced in pigs receiving a higher dose of microparticles. The effect on neuronal nitric oxide synthase-, and substance P-positive neurons, depends on the examined plexus and the dose of microparticles. An increase in the percentage of galanin-positive neurons and a decrease in cocaine and amphetamine-regulated transcript-, vesicular acetylcholine transporter-, and vasoactive intestinal peptide-positive neurons do not show such relationships. The present study shows that microparticles can potentially have neurotoxic and pro-inflammatory effects, but there is a need for further research to determine the mechanism of this process and possible further effects. [ABSTRACT FROM AUTHOR]

Changes in the existence of mangroves will have an impact on changes in food webs in their respective areas. The purpose of this study was to determine the food source of the macrozoobenthos community within the Lubuk Damar mangrove ecosystem. Stable isotopes, carbon and nitrogen were used to describe the food sources for macrozoobenthos in the mangrove ecosystem of the Lubuk Damar Ecosystem, Aceh Tamiang, Indonesia. The stable isotope analysis of 13C and 15N was carried out using Isotopic-Ratio Mass Spectrometry. Potential food sources at the study site based on stable isotope ratios ranged between –29.08‰ to –20.66‰ (δ13C) and 4.07‰ to 5.63‰ (δ15N); macrozoobenthos –25.00‰ to –14.76‰ (δ13C) and 5.59‰ to 7.73‰ (δ15N). The potential food sources tested at the study site consisted of seven sources, but not all food sources in the ecosystem were consumed by the invertebrate community. This study shows that mangrove leaf litter serves as a food source for some invertebrates, such as the bivalves, gastropods, polychaetes, sipunculans, brachiopods and crustaceans. The results of this study evidence that the examined mangrove ecosystem has a function as a provider of food sources in the surrounding waters, therefore its existence is very important supporting diversity of coastal waters. [ABSTRACT FROM AUTHOR]

Infections caused by bacteria originating from tainted food sources are a widespread concern due to their large economic impact and detrimental effects on public health. We aimed to explore literature focusing on the presence of Salmonella in the food supply chains of Gulf Cooperation Council (GCC) countries and to provide an overview of available information concerning healthrelated issues and the status of salmonellosis in humans in GCC countries. The reviewed evidence underscored a gap in our comprehensive understanding of the prevalence of Salmonella in the food supply of GCC countries. Molecular characterization efforts to pinpoint the sources of Salmonella in these nations were limited. Surveys targeting Salmonella in the food supply of GCC countries have been infrequent. While qualitative data indicated the presence or absence of Salmonella, there was a noticeable lack of quantitative data detailing the actual quantities of these bacteria in chicken meat supplies across GCC countries. Although reports regarding Salmonella in animal-derived foods were common, the literature highlighted in this review emphasized the persistent challenge that Salmonella pose to food safety and public health in GCC countries. Addressing this issue requires concerted efforts to enhance surveillance, improve control measures, and promote greater awareness among stakeholders in the food supply chain. [ABSTRACT FROM AUTHOR]

An investigation was carried out with 20 samples comprising soil, water, forage, blood serum and milk of cow to assess heavy metal contamination during 2018-19 and 2019-20 in Coimbatore district in Tamil Nadu, India. The results indicated that in soil, chromium residue 741.05 ppm and 1338.1 ppm, lead residue was 168.2 ppm and 164.2 ppm and cadmium 119.2 ppm and 76.14 ppm was in rural and urban areas, respectively. In water, chromium residue was 1.842 ppm and 2.192 ppm, lead residue was 0.816 ppm and 0.973 ppm and cadmium (Cd) was 0.586 ppm and 1.298 ppm in rural and urban areas respectively. In forages, chromium was 1159 ppm and 1712 ppm, lead residue was 341.6 ppm and 398.0 ppm and cadmium residue were 112.2 ppm and 1051 ppm in rural and urban areas, respectively. In the cow serum, chromium residue were 4463 ppm and 4283 ppm, lead residue was 421.3 ppm and 406.9 ppm, and cadmium residue was 409.2 ppm and 323.7 ppm and in the milk, the chromium residue were 101.4 ppm and 165.3 ppm, lead residue was 6.538 ppm and 6.593 ppm, and cadmium residue was 3.905 ppm and 11.23 ppm in urban and rural areas, respectively. The study indicated that heavy metal contamination in soil and water is transferred to dairy cattle and thus result in heavy metal accumulation in blood serum and milk. [ABSTRACT FROM AUTHOR]

Due to their natural history and ecological attributes, turtles are excellent organisms for studies of heavy metal contamination. Turtles have a large geographical distribution, occupy different aquatic habitats, and occupy various trophic levels. The present study investigated mercury bioaccumulation in the carnivorous chelonian Chelus fimbriata (Matamata turtle) and Hg biomagnification in relation to its aquatic food chain in the middle Rio Negro, AM-Brazil. Tissue samples of muscle, carapace and claws were collected from 26 C. fimbriata individuals, as well as collections of autotrophic energy sources found in the turtle's aquatic habitat area. The samples were collected in February-March/2014 and analyzed for THg concentrations and carbon (δ13C) and nitrogen (δ15N) stable isotopes. The highest THg levels were found in claws (3780 ng.g−1), carapace (3622 ng.g−1) and muscle (403 ng.g−1), which were found to be significantly different [F(2.73) = 49.02 p < 0.01]. However, THg concentrations in muscle tissue were below the consumption threshold indicated by the WHO and Brazilian Health Ministry. The average δ13C and δ15N values in Matamata samples were −31.7‰ and 11.9‰, respectively. The principal energy source sustaining the food chain of C. fimbriata was found to be terrestrial shrubs, with smaller contributions from emergent aquatic herbaceous plants and algae, while δ15N values showed its trophic position to be two levels above the autotrophic energy sources. There was a positive correlation between THg and turtle size, while a significant relationship was found between THg and δ15N, showing strong biomagnification in the food chain of C. fimbriata: y = 0.21x + 0.46; r2 = 0.45; p < 0.001, for which the slope presented a value of 0.21. [ABSTRACT FROM AUTHOR]

The increase in market concentration and market power in the food supply chain is an issue of concern globally. This study focuses on an analysis of market imperfections in the Italian processed tomato food supply chain by considering changes in its supply chain governance from 2006–2018. The identification of the degree of non‐competitive behavior is based on the derived mark‐down and mark‐up models using the latest developments in stochastic frontier methodology. The estimated models reveal some degree of non‐competitive behavior in the input as well as in the output processing market. However, in consideration of the results on the supply chain governance during the study period, we argue that the establishment of an Interbranch Organization (IBO) could create fairly stable long‐term food supply chain relationships benefitting all IBO members and in particular farmers despite the significant change in concentration levels in the Italian tomato processing sector after 2015. [ABSTRACT FROM AUTHOR]

A dynamic competition in a free market comprises its own mechanisms for balancing the supply and demand of goods and services. The paper proposes an analysis of companies in the agri-food sector in Moldova, focusing on their turnover and geographical distribution by regions. Open-access articles from Clarivate, Google Scholar, and ResearchGate were used for the literature review. Official data provided by National Bureau of Statistics were utilized for the research. The results showed a significant increase in cumulative turnover for operators in the food industry during 2015-2021. In 2022, regarding the concentration level of companies across different geographic regions, the highest concentration was observed in Chisinau Municipality and the lowest in the ATU Gagauzia. The study highlighted an Inverse Herfindahl-Hirschman Index in Chisinau Municipality and a minimum the ATU Gagauzia Region. The analysis conducted is part of the doctoral training stage. [ABSTRACT FROM AUTHOR]

Although massive biomass fluctuations of coastal-pelagic fishes are an iconic example of the impacts of climate variability on marine ecosystems, the mechanisms governing these dynamics are often elusive. We construct a 45-year record of nitrogen stable isotopes measured in larvae of Northern Anchovy (Engraulis mordax) in the California Current Ecosystem to assess patterns in food chain length. Larval trophic efficiency associated with a shortened food chain increased larval survival and produced boom periods of high adult biomass. In contrast, when larval food chain length increased, and energy transfer efficiency decreased, the population crashed. We propose the Trophic Efficiency in Early Life (TEEL) hypothesis, which states that larval fishes must consume prey that confer sufficient energy for survival, to help explain natural boom-bust dynamics of coastal pelagic fishes. Our findings illustrate a potential for trophic indicators to generally inform larval survival and adult population dynamics of coastal-pelagic fishes.

Cigarette butts are one of the most prevalent forms of litter worldwide and may leach toxic compounds when deposited in aquatic environments. Previous studies demonstrated that smoked cigarette leachate is toxic toward aquatic organisms. However, the specific bioavailable chemicals from the leachate and the potential for human and wildlife exposure through the food chain were unknown. Using a nontargeted analytical approach based on GC×GC/TOF-MS, 43 compounds were confirmed to leach from smoked cigarettes when exposed to a water source. Additionally, the bioaccumulation potential of organic contaminants in an edible fish, rainbow trout (Oncorhynchus mykiss), was assessed through direct exposure to the leachate of smoked cigarettes at 0.5 CB/L for 28 days. There was a significant reduction in fish mass among the exposed rainbow trout vs the control group (χ2 (1) = 5.3, p = 0.021). Both nontargeted and targeted chemical analysis of representative fish tissue identified four tobacco alkaloids, nicotine, nicotyrine, myosmine, and 2,2'-bipyridine. Their average tissue concentrations were 466, 55.4, 94.1, and 70.8 ng/g, respectively. This study identifies leached compounds from smoked cigarettes and demonstrates the uptake of specific chemicals in rainbow trout, thus suggesting a potential for accumulation in food webs, resulting in human and wildlife exposure.

Aquatic ecosystems world-wide are being irreversibly altered, suggesting that new and innovative management strategies are necessary to improve ecosystem function and sustainability. In river ecosystems degraded by dams environmental flows and selective withdrawal (SWD) infrastructure have been used to improve habitat for native species. Yet, few studies have quantified nutrient and food web export subsidies from upstream reservoirs, despite their potential to subsidize downstream riverine food webs. We sampled nutrient, phytoplankton, and zooplankton concentrations in outflows from the Shasta-Keswick reservoir complex in Northern California over a 12-month period to understand how SWD operation and internal reservoir conditions interact to influence subsidies to the Sacramento River. We found that nutrients, phytoplankton, and zooplankton were continuously exported from Shasta Reservoir to the Sacramento River and that gate operations at Shasta Dam were important in controlling exports. Further, our results indicate that gate operations and water-export depth strongly correlated with zooplankton community exports, whereas internal reservoir conditions (mixing and residence time) controlled concentrations of exported zooplankton biomass and chlorophyll a. These results demonstrate that reservoirs can be an important source of nutrient and food web subsidies and that selective withdrawal infrastructure may provide a valuable management tool to control ecosystem-level productivity downstream of dams.

In this study, we introduce a novel tri-trophic food chain model that integrates cannibalism among basal prey and harvesting behaviors in the top predator, aiming to understand ecosystem dynamics comprehensively. Objectives encompass assessing system boundedness, computing fixed points, and determining stability characteristics using mathematical frameworks. The Routh-Hurwitz criteria and Lyapunov function are employed for local and global stability analyses of coexistence equilibrium points. Graphical interpretations elucidate relationships among pivotal parameters: prey growth rate, cannibalism intensity, and predator predation rate. Phase portraits and time series solutions illustrate parameter impacts. To enhance analytical depth and predictive capabilities, we utilize artificial neural networks (ANNs). Methods include connecting ANNs to computational proficiency for insights into the model's behavior over time. Findings demonstrate system boundedness, computed fixed points, and stability characteristics. Graphical interpretations reveal parameter impacts on system dynamics. ANNs offer predictive insights into model behavior. This study's novelty lies in integrating cannibalism and harvesting behaviors into a tri-trophic food chain model, employing mathematical analyses and ANNs to understand ecosystem dynamics comprehensively. Improvements include predictive capabilities and deeper analytical insights. Doi: 10.28991/ESJ-2024-08-04-02 Full Text: PDF

Ectomycorrhizal (ECM) fungi, which can form ectomycorrhiza with plants, are an important link between the above-ground symbiotic plants and the subsurface ecosystems, and many of them are nutritious and delicious food. ECM fungi promote the absorption of mineral nutrients by plants, especially for limiting mineral elements such as phosphorus, thereby improving the growth of plants. It is generally believed that ECM fungi acquire mineral nutrients from soil mainly through their weathering effect on soil minerals that are difficult to degrade, but the weathering process and mechanisms are still not clear. Through field investigation, strain isolation and weathering tests, it is found that many ECM fungi cannot weather minerals by up-regulating the synthesis of small molecular organic acids, showing a weak ability to weather mineral. Particularly, they cannot use phosphorus in apatite independently. Bio-omics studies find that in forest soils, some ECM fungi with weaker weathering ability can promote the dissolution of minerals by enrichment of mineral-weathering bacteria, and absorb dissolved mineral nutrients to supply host plants through their high-affinity ion transport systems. In addition, ECM fungi can enrich special versatile oxalate-degrading bacteria (such as those that have the capability of nitrogen fixation and promoting mycorrhizal formation) to eliminate the inhibitory effect of excess oxalate on mineral weathering and nutrient absorption. It has been confirmed that ECM fungi can regulate the rhizosphere microbial community structure and promote the mutually cooperative relationship among plants, fungi and bacteria to maintain a healthy and sustainable forest ecosystem. This paper reviews the symbiotic strategies of ECM fungi from the perspective of mineral weathering, puts forward new ideas for increasing the biomass of edible fungi in woodlands and promoting the sustainability of woodland ecosystems, and gives an outlook on future research directions in this field.

Soil viral ecology is a growing research field; however, the state of knowledge still lags behind that of aquatic systems. Therefore, to facilitate progress, the first Soil Viral Workshop was held to encourage international scientific discussion and collaboration, suggest guidelines for future research, and establish soil viral research as a concrete research area. The workshop took place at Søminestationen, Denmark, between 15 and 17th of June 2022. The meeting was primarily held in person, but the sessions were also streamed online. The workshop was attended by 23 researchers from ten different countries and from a wide range of subfields and career stages. Eleven talks were presented, followed by discussions revolving around three major topics: viral genomics, virus-host interactions, and viruses in the soil food web. The main take-home messages and suggestions from the discussions are summarized in this report.

Spatial dynamics can promote persistence of strongly interacting predators and prey. Theory predicts that spatial predator-prey systems are prone to long transients, meaning that the dynamics leading to persistence or extinction manifest over hundreds of generations. Furthermore, the form and duration of transients may be altered by spatial network structure. Few empirical studies have examined the importance of transients in spatial food webs, especially in a network context, due to the difficulty in collecting the large scale and long-term data required. We examined predator-prey dynamics in protist microcosms using three experimental spatial structures: isolated, river-like dendritic networks and regular lattice networks. Densities and patterns of occupancy were followed for both predators and prey over a time scale that equates to >100 predator and >500 prey generations. We found that predators persisted in dendritic and lattice networks whereas they went extinct in the isolated treatment. The dynamics leading to predator persistence played out over long transients with three distinct phases. The transient phases showed differences between dendritic and lattice structures, as did underlying patterns of occupancy. Spatial dynamics differed among organisms in different trophic positions. Predators showed higher local persistence in more connected bottles while prey showed this in more spatially isolated ones. Predictions based on spatial patterns of connectivity derived from metapopulation theory explained predator occupancy, while prey occupancy was better explained by predator occupancy. Our results strongly support the hypothesized role of spatial dynamics in promoting persistence in food webs, but that the dynamics ultimately leading to persistence may occur with long transients which in turn may be influenced by spatial network structure and trophic interactions.

ObjectiveTo determine the drug sensitivity and molecular typing characteristics of Klebsiella pneumoniae isolated from meat and diarrhea samples in a local area.MethodsSeventy-one strains of K.pneumoniae were isolated from 118 meat food （chicken and pork） randomly sampled in the markets in Jinshan District， Shanghai， 2020‒2021， and 1 499 diarrhea samples from outpatient diarrhoea patients in hospitals in the same district. Then drug susceptibility testing was conducted by micro-broth dilution method， and sequence identity was determined by pulsed field gel electrophoresis（PFGE）.ResultsThe overall detection rate of K.pneumoniae in meat was 11.86% （14/118）， with detection rate 20.93% （9/43） in chicken and 6.67% （5/75） in pork. The difference in detection between meats was statistically significant （χ2=5.317，P

The low student learned outcomes on the topic of food chains, as well as the less varied instructional media used by teachers, was the background of this researched. This researched aimed to developed, assess the feasibility, and tested the effectiveness of the Artsteps Virtual Exhibition learned media in enhancing learned outcomes on food chain material for fifth-grade students at one of elementary school in Semarang City. This typed of researched researched and development (R&D) utilizing the Borg and Gall development model, which consisted of 10 stages. However, the researcher only reached stage 9. Subject mattered experts and media experts conducted the product validity tested. The results of this researched included the development process of artsteps learned media on the topic of food chains; the validity of Artsteps learned media, which assessed as highly valid from students' responses to Artsteps learned media fell into the category of excellent; and the SPSS result indicating a significant difference in outcomes before and after the treatment. Therefore, Artsteps learned media could improved students' learning outcomes on food chain material.

The transformation of the food chain due to technological advances has had significant implications in regard to food safety. A noteworthy trend in this evolution relates to the emergence of new or previously unseen pathogens within products, thereby altering the landscape of foodborne illness epidemiology. The escalating frequency of these events underscores the need for a comprehensive re-evaluation of preventive strategies. The occurrence of novel species of bacteria, viruses, parasites, and unusual biotoxins from unexpected sources has challenged the previous limits that had been set to prevent foodborne illness outbreaks. The repercussions, ranging from detrimental effects on public health to economic burden, are influenced by a myriad of factors affecting the evolution of foodborne pathogens and emerging ailments. Among these factors are shifts in population demographics and behaviors, especially dietary patterns, as well as climate extremes, advances in more precise pathogen detection, microbial adaptation, evolving agricultural practices, and transformative changes within the food industry. This review critically examines the impact of technological metamorphosis along the food chain, encompassing production, processing, handling, packaging, storage, transportation, and industry demographics on the dynamics influencing the emergence of foodborne pathogens. Additionally, potential solutions to mitigate and manage this escalating issue are proposed. [ABSTRACT FROM AUTHOR]

Fertilization can change the composition of antibiotic resistance genes(ARGs) and their host bacteria in agricultural fields, while complex microbial activities help ARGs into crops and transmit them to humans through agricultural products.Therefore, this study constructed a farmland food chain with soil-lettuce-snail as a typical structure, added genetically engineered Pseudomonas fluorescens containing multidrug-resistant plasmid RP4 to track its spread in the farmland food chain, and used different fertilization methods to explore its influence on the spread and diffusion of ARGs and intl1 in the farmland food chain. It was found that exogenous Pseudomonas can enter plants from soil and pass into snails' intestines, and there is horizontal gene transfer phenomenon of RP4 plasmid in bacteria. At different interfaces of the constructed food chain, the addition of exogenous drug-resistant bacteria had different effects on the total abundance of ARGs and intl1. Fertilization, especially manure, not only promoted the spread of Pseudomonas aeruginosa and the transfer of RP4 plasmid levels, but also significantly increased the total abundance of ARGs and intl1 at all interfaces of the constructed food chain. The main ARGs host bacteria in the constructed food chain include Proteobacteria, Bacteroides, and Firmicutes, while Flavobacterium of Bacteroides is the unique potential host bacteria of RP4 plasmid. In conclusion, this study provides a reference for the risk assessment of ARGs transmitted to the human body through the food chain, and has important practical significance to reduce the antibiotic resistance contamination of agricultural products and ensure the safety of vegetable basket. [ABSTRACT FROM AUTHOR]

The impact of heavy metals on agricultural ecosystems has consistently been a topic of social concern. This study investigated the translocation of lead (Pb) along the soil – Vicia faba L. (Fabales: Fabaceae) – Megoura crassicauda (Hemiptera: Aphidoidea) – Harmonia axyridis (Coleoptera: Coccinellidae) system. Lead in soil could be transferred to broad bean, and the accumulation amount was highest in roots, followed by stems and leaves. Aphids and ladybirds could also accumulate lead through the food chain. Interestingly, the lead content of broad bean roots in the aphid feeding group was significantly higher than that in the non-aphid feeding group. Lead stress significantly reduced the germination rate and seedling height of broad bean, and inhibited root elongation. The expression levels of trehalase (TRE), trehalose-6-phosphate synthase (TPS), and vitellogenin (Vg), TRE activity, and carbohydrate content in aphids changed under lead treatment. The number of offspring produced by the second and fifth generation aphids was significantly reduced under lead treatment. Furthermore, high concentrations of lead treatment can prolong the development time of the 2nd and 3rd instar larvae of the ladybird. Feeding on aphids contaminated with lead can affect the survival of ladybirds. Our results further confirm the biological transfer of lead in the food chain and explore the adaptive mechanisms of aphids and ladybirds. These relevant results provide a theoretical basis for further exploring the molecular mechanism of lead homeostasis in plants and insects under lead stress. [ABSTRACT FROM AUTHOR]

Food production is a complex matter, affecting people's lives, organizations' profits, and the well-being of the whole planet, and has multifaceted ethical considerations surrounding its production, distribution, and consumption. This paper addresses the pressing need to confront ethical challenges within the food system, encompassing issues such as environmental sustainability, food security, and individual food choices for better oral and systemic health of all individuals around the globe. From agricultural practices to global trade and food waste, ethical implications are addressed across various domains, highlighting the interconnectedness of ethical decision-making in the food industry. Central themes explored include the ethical dimensions of food production methods, the impact of global trade on food ethics, and the role of individuals in making ethically informed food choices. Additionally, this paper considers the spiritual and physical significance of food, particularly through the lens of oral health as a gateway to holistic well-being. Recognizing the complexity of the food and mouth ecosystem, this paper calls for serious interventions in legislation and economics to promote ethical protocols and techniques for sustainability reasons. It emphasizes the importance of ethical considerations in food safety management systems, regulatory frameworks, and quality standards. Moreover, this paper underlines the need for a comprehensive approach to address ethical dilemmas and moral values inherent in the food industry and oral health policies, adopting the precautionary principle and ethical decision-making frameworks. This article finally aims to serve as a call to action for stakeholders across the food industry and the healthcare sector, to prioritize ethical practices, promote transparency, rearrange economic parameters, and work towards a more sustainable and equitable food system for inner and outer oral and systemic health and human sustainability for all. [ABSTRACT FROM AUTHOR]

The idea that changing environmental conditions drive adaptive evolution is a pillar of evolutionary ecology. But, the opposite-that adaptive evolution alters ecological processes-has received far less attention yet is critical for eco-evolutionary dynamics. We assessed the ecological impact of divergent values in a key adaptive trait using 16 populations of the brown anole lizard (Anolis sagrei). Mirroring natural variation, we established islands with short- or long-limbed lizards at both low and high densities. We then monitored changes in lower trophic levels, finding that on islands with a high density of short-limbed lizards, web-spider densities decreased and plants grew more via an indirect positive effect, likely through an herbivore-mediated trophic cascade. Our experiment provides strong support for evolution-to-ecology connections in nature, likely closing an otherwise well-characterized eco-evolutionary feedback loop.

Predator-prey interactions are one of ecology's central research themes, but with many interdisciplinary implications across the social and natural sciences. Here we consider an often-overlooked species in these interactions, namely parasites. We first show that a simple predator-prey-parasite model, inspired by the classical Lotka-Volterra equations, fails to produce a stable coexistence of all three species, thus failing to provide a biologically realistic outcome. To improve this, we introduce free space as a relevant eco-evolutionary component in a new mathematical model that uses a game-theoretical payoff matrix to describe a more realistic setup. We then show that the consideration of free space stabilizes the dynamics by means of cyclic dominance that emerges between the three species. We determine the parameter regions of coexistence as well as the types of bifurcations leading to it by means of analytical derivations as well as by means of numerical simulations. We conclude that the consideration of free space as a finite resource reveals the limits of biodiversity in predator-prey-parasite interactions, and it may also help us in the determination of factors that promote a healthy biota.