Marine Ecosystems Research Articles

David Henry Cushing. 14 March 1920 — 14 March 2008

David Cushing was Britain's foremost twentieth-century marine fisheries ecologist, who did more than anyone else to develop the subject into a distinctive science over a career of more than 50 years. He was born and raised in Northumberland, and took both his first degree and a DPhil at Oxford, separated by war service in the Royal Artillery. He married Diana Antona-Traversi in 1943, and they had one daughter, Camilla. He worked for the whole of his career at the Fisheries Laboratory, Lowestoft, where he started in 1946 as a scientific officer, studying plankton off the northeast coast of England, and eventually becoming deputy director and head of the Fish Population Dynamics Divi­sion until his retirement in 1980. He published around 200 papers and reports, and wrote 11 books on marine ecology and fisheries, with four principal areas of interest: fisheries acoustics; planktonic biological production in the sea; the causes of the collapse of the North Sea herring; and the factors controlling recruitment of young fish, notably the influences of stock size and of climate. He famously proposed the match/mismatch hypothesis to explain how the great variability of fish recruitment arises from minor variations in climate from year to year. He died on 14 March 2008, on his eighty-eighth birthday.

CO2‐induced seawater acidification impairs the stinging cells of a jellyfish

AbstractCO2‐induced seawater acidification has been shown to modify predator–prey interactions in many marine taxa. Scyphozoans play an important role in the trophic dynamics of marine ecosystems during their blooms in coastal waters; however, the impacts of seawater acidification on the predation behavior of these animals are poorly understood. Here, we aimed to examine the impact of a decrease in seawater pH on the feeding behavior and growth of ephyrae (juvenile medusae) of the scyphozoan Aurelia coerulea. Combining bulk and single‐cell RNA sequencing approaches, we assessed transcriptomic changes of ephyrae under a laboratory‐based pH 7.6 condition. We found that the feeding rates and growth of ephyrae were significantly inhibited by a decrease in seawater pH. Furthermore, transcriptome analysis showed that a decline in pH significantly reduced the expression of genes related to toxins and nematocyst structure in ephyrae. These findings were further confirmed by single‐cell transcriptomic analyses and revealed that low pH impaired the toxin activity and energy metabolism of stinging cells. The pH recovery experiment indicated that moving ephyrae from seawater with pH 7.6 into seawater with pH 8.1 greatly restored their feeding, growth, and toxin‐related and nematocyst structure–related gene expression. However, exposure to pH 7.6 for 23 d could not recover the decrease in the feeding and growth of ephyrae. Together, these findings indicate that CO2‐induced acidification compromised the stinging cells of A. coerulea ephyrae, with concomitant negative consequences on predation and growth that are likely to alter predator–prey interactions, with consequent effects on community structure and ecosystem.

A mapped dataset of surface ocean acidification indicators in large marine ecosystems of the United States

Mapped monthly data products of surface ocean acidification indicators from 1998 to 2022 on a 0.25° by 0.25° spatial grid have been developed for eleven U.S. large marine ecosystems (LMEs). The data products were constructed using observations from the Surface Ocean CO2 Atlas, co-located surface ocean properties, and two types of machine learning algorithms: Gaussian mixture models to organize LMEs into clusters of similar environmental variability and random forest regressions (RFRs) that were trained and applied within each cluster to spatiotemporally interpolate the observational data. The data products, called RFR-LMEs, have been averaged into regional timeseries to summarize the status of ocean acidification in U.S. coastal waters, showing a domain-wide carbon dioxide partial pressure increase of 1.4 ± 0.4 μatm yr−1 and pH decrease of 0.0014 ± 0.0004 yr−1. RFR-LMEs have been evaluated via comparisons to discrete shipboard data, fixed timeseries, and other mapped surface ocean carbon chemistry data products. Regionally averaged timeseries of RFR-LME indicators are provided online through the NOAA National Marine Ecosystem Status web portal.

Sargassum horneri extract fermented by Lactiplantibacillus pentosus SH803 mediates adipocyte metabolism in 3T3-L1 preadipocytes by regulating oxidative damage and inflammation

Sargassum horneri (S. horneri), a brown seaweed excessively proliferating along Asian coastlines, are damaging marine ecosystems. Thus, this study aimed to enhance nutritional value of S. horneri through lactic acid bacteria fermentation to increase S. horneri utilization as a functional food supplement, and consequently resolve coastal S. horneri accumulation. S. horneri supplemented fermentation was most effective with Lactiplantibacillus pentosus SH803, thus this product (F-SHWE) was used for further in vitro studies. F-SHWE normalized expressions of oxidative stress related genes NF-κB, p53, BAX, cytochrome C, caspase 9, and caspase 3, while non-fermented S. horneri (SHWE) did not, in a H2O2-induced HT-29 cell model. Moreover, in an LPS-induced HT-29 cell model, F-SHWE repaired expressions of inflammation marker genes ZO1, IL1β, IFNγ more effectively than SHWE. For further functional assessment, F-SHWE was also treated in 3T3-L1 adipocytes. As a result, F-SHWE decreased lipid accumulation, along with gene expression of adipogenesis markers PPARγ, C/EBPα, C/EBPβ, aP2, and Lpl; lipogenesis markers Lep, Akt, SREBP1, Acc, Fas; inflammation markers IFN-γ and NF-κB. Notably, gene expression of C/EBPβ, IFN-γ and NF-κB were suppressed only by F-SHWE, suggesting the enhancing effect of fermentation on obesity-related properties. Compositional analysis attributed the protective effects of F-SHWE to acetate, an organic acid significantly higher in F-SHWE than SHWE. Therefore, F-SHWE is a novel potential anti-obesity agent, providing a strategy to reduce excess S. horneri populations along marine ecosystems.

The complete mitogenome of the Atlantic longnose chimaera Rhinochimaera atlantica (Holt & Byrne, 1909)

Holocephali is a subclass of chondrichthyans with ample geographic distribution in marine ecosystems. Holocephalan species are organized into three families: Callorhinchidae, Chimaeridae, and Rhinochimaeridae. Despite the critical ecological and evolutionary importance, genomic information from holocephalans is still scarce, particularly from rhinochimaerids. The present study provides the first complete mitogenome of the Atlantic longnose chimaera Rhinochimaera atlantica (Holt & Byrne, 1909). The whole mitogenome was sequenced from an R. atlantica specimen, collected on the Porcupine Bank (NE Atlantic), by Illumina high-throughput sequencing. The R. atlantica mitogenome has 17,852 nucleotides with 13 protein-coding genes, 22 transfer RNA, and two ribosomal RNA genes. Nine of these genes are in the complementary strand. This mitogenome has a GC content of 41.5% and an AT content of 58.5%. The phylogenetic reconstruction provided here, using all the available complete and partial Holocephali mitogenomes, places R. atlantica in the Rhinochimaeridae family, as expected. This genomic resource will be useful in the genomic characterization of this species.

Network analyses on photographic surveys reveal that invertebrate predators do not structure epibenthos in the deep (~2000m) rocky Powell Basin, Weddell Sea, Antarctica

Predator-prey interactions in marine ecosystems control population sizes, maintain species richness, and provide intermediate disturbance. Such ecosystem structuring interactions may be rare in Antarctic epibenthic communities, which are unique among marine ecosystems worldwide for their dominance of soft bodied fauna (sponges, soft and hard corals, and echinoderms) and a simultaneous paucity of shell crushing predators (sharks, rays and durophagous decapods). In the shallow benthos, instead of durophagy, important Antarctic predators such as starfish, pycnogonids (sea spiders), nemertean worms, and nudibranchs employ grazing, scavenging, or sucking strategies. Far less is known about deep sea (>1000 m) Antarctic benthic communities due to the challenging nature of polar data collection, so that photographic surveys provide one of the only means of making in situ observations of these deep sea communities. We used seabed photographs of the deep (~2000m) slope of the Powell Basin, northwest Weddell Sea, taken by the Ocean Floor Observation and Bathymetry System on board the RV Polarstern (PS118, April 2019) to investigate the epibenthic community composition, and Bayesian Network Inference (BNI) to determine the ecological network, namely the ecological associations, including potential invertebrate predator-prey relationships between taxa. Photographs show that the rocky substrates of the basin slope support between 10-22 morphotaxa per photo, and highly abundant communities (density between 106 to 553 individuals/m2). BNI results reveal a network of associations between the sessile and mobile suspension and filter feeding organisms and their physical environment. However, associations between invertebrate predators like starfish, and other organisms, were not detected in the network. This lack of inclusion within the network suggests that, despite the presence of these normally important mobile predators, invertebrate predator-prey interactions on the rocky Powell Basin slope do not have the same ecosystem-regulating impact that they do on shallow Antarctic epibenthic communities.

Public attitudes and emotions toward novel carbon removal methods in alternative sociotechnical scenarios

Abstract Despite high expectations about the role of carbon removal in meeting global climate targets, many of the proposed techniques remain nascent. This is especially so for techniques with potential for large-scale, permanent removal of CO2, such as Direct Air Carbon Capture and Storage (DACCS) and Ocean Alkalinity Enhancement (OAE). In such a context, understanding public attitudes is crucial but challenging, since we do not have enough information about the sociotechnical configurations which might accompany such proposals over future timescales. Carbon removal at scale will not take place in a vacuum – it will co-evolve within political, social, economic, and legal structures which in turn will have a strong influence on public attitudes. This study used a nationally-representative survey (n=1,978) in the UK to test the impact of alternative sociotechnical systems on public attitudes to DACCS and OAE. Participants were randomly assigned to one of five scenario conditions, representing different forms of governance logic (top-down vs bottom-up) and market logic (planned vs liberal economy), plus one with minimal sociotechnical information. We find that the scenario condition significantly impacted perceptions of OAE, with participants preferring its implementation within a bottom-up, planned economy scenario, and rejecting scenarios which most closely resembled the status quo. There were no significant differences between scenarios for DACCS, suggesting that the technology may be more flexible across alternative sociotechnical arrangements. OAE arouses more negative emotions, particularly worry about impacts on ocean ecosystems, whereas DACCS arouses more hope. We found that climate worry is associated with stronger emotions – both positive and negative – toward both techniques, thus CDR could be polarising for the most climate-worried, likely due to tensions between climate urgency and concerns about deterring emissions reductions. The most important criteria for future CDR deployment were deemed to be biodiversity, durability, and cost, with a strong discourse around the current cost-of-living crisis.

Cory's Shearwater (Calonectris borealis): Exploring Normal Head Anatomy through Cross-Sectional Anatomy, Computed Tomography and Magnetic Resonance Imaging.

Cory's shearwater, or Calonectris borealis, stands out as a symbolic figure in the world of seabirds, playing a crucial role in marine ecosystems globally. Belonging to the Procellariidae family, it is singularized by its imposing wingspan and intricate migration patterns connecting it to various regions from the North Atlantic to the Pacific. Its role in the marine food chain, specialized diet and adaptation for nesting in the Canary Archipelago underscore its ecological importance. However, Cory's shearwater also faces important threats, such as the invasion of foreign species, highlighting the need for its conservation. Among the conservation issues, studies on its biology, the main threats it faces and its normal anatomy are essential to preserve marine biodiversity. Additionally, a variety of imaging techniques, such as computed tomography and magnetic resonance, facilitates the understanding of the bird's neuroanatomy and opens future research possibilities in comparative neuroscience. Moreover, this approach proves particularly relevant given the increasing attention these seabirds receive in environments such as zoos, rehabilitation centers and their natural habitat, where veterinarians play a crucial role in their care and well-being.

The Effects of Ocean Governance on Marine Economic Development from an Environmental Optimization Perspective

The oceans and seas are vital resources for human life and fundamental to global economic growth. With the expansion of globalization and increasing demand for resource exploitation, the ocean economy has emerged as a critical support for economic growth and a significant concern for many. However, the exploitation of marine resources often leads to ecological damage and environmental pollution, seriously threatening the long-term viability of the marine economy. Measures must be implemented to balance ecological protection and economic development for sustainable growth in the marine sector. This investigation synthesizes over a decade’s worth of data from various coastal cities, incorporating insights from national databases, international reports, and scholarly articles, resulting in an analysis of more than 500 data points. Through the application of a rigorous quantitative approach and a dual fixed-effect model, the study delves into the dynamics between ocean governance and economic development. By analyzing a broad and representative dataset, the research provides an exhaustive overview of global ocean governance frameworks and the current state of the marine economy. The statistical analyses unveil the complexity and diversity of factors influencing the development and governance of marine economies. This paper explores the interplay between marine economic development and ocean governance, evaluating the impact of governance on marine economic progression within the context of environmental optimization. Furthermore, it proposes policy interventions aimed at fostering the sustainable growth of marine economies, ensuring the conservation of marine ecosystems, and pursuing overarching long-term global growth ambitions.

Comparison of Juvenile Pacific Salmon abundance, distribution, and body condition between Western and Eastern Bering Sea using spatiotemporal models

Recent changes in climate have had generally negative impacts on salmon stocks in the eastern and positive effects in the western Bering Sea (WBS). Eastern Bering Sea (EBS) salmon stocks have periodically experienced reduced productivity, size, and survival, whereas salmon stocks in the western Bering Sea (WBS) have tended to be more stable, with some stocks increasing in abundance. This difference could be partially attributed to the different habitats that juvenile salmon occupy during their first marine year, which often determines recruitment. Here, we used salmon surveys in the EBS and WBS to compare the status of juveniles in these two large marine ecosystems. We applied spatio-temporal vector autoregressive spatio-temporal (VAST) models to adjust for differences in timing, vessels and trawl gear used, and to compare the relative abundance and body condition indices (length, weight, and Fulton's condition factor) of three juvenile salmon species pink, chum and sockeye salmon (Oncorhynchus gorbuscha, O. keta, and O.nerka respectively) between the WBS and EBS from 2002 to 2022. Juvenile salmon in WBS exhibited a consistent trend of larger size and higher Fulton's condition factor, with greater abundance compared to EBS in even years. A clear even-odd year pattern, which is believed to be driven by pink salmon, occurred in all species’ relative abundance and body condition in the WBS, with a limited impact of interannual temperature changes. Conversely, temperature had a significant impact on EBS salmon, with much of the variation in relative abundance and body condition occurring between warm and cold periods, and even/odd patterns were found only in pink salmon relative abundance and body condition. We detected different WBS-EBS migration patterns, with EBS juveniles dispersing from nearshore habitats earlier than WBS juveniles but migrating offshore later that is connected to bathymetry and the broad shelf in the EBS.

Organochlorine pesticides in fat tissue of cetaceans at the Crimean coast of the Black Sea

Accumulation of persistent organochlorine pesticides (OCP) in fat tissue was examined for the mammals found released ashore along the Crimean coast of the Black Sea in 2018–2022. This group of animals is positioned at the top of food chain in the local marine ecosystem. Statistically significant dependence of the accumulation on sex (males are more contaminated than females) and age (adults and juveniles are more contaminated than calves and neonates) is found. Besides, the pesticides concentration in fat from dorsal tissue is generally higher than in fat from caudal stem, but the difference is not significant. In the tissue of harbor porpoises and common dolphins, the mean OCP concentration decreased in the order: p,p′-DDE > β-HCH > p,p′-DDD > p,p′-DDT, whereas bottlenose dolphins had the order: p,p′-DDE > p,p′-DDD > β-HCH > p,p′-DDT. The most common metabolites were DDE, and their accumulation was the highest. The concentration of DDD was considerably lower, and significant accumulation of DDT was observed rarely, so the mean concentration of these group of metabolites was the lowest.

The Effect of Environmentally Unfriendly Fishing Gear on The Welfare of Fisher in Morodemak Village, Demak Regency

This study aims to see the effect of the use of fishing gear that is not environmentally friendly on the welfare level of fisher in Morodemak Village, Demak Regency. The method used in this study is a snowballing technique for sample collection through interviews so that 50 respondents are obtained, then the analysis method used is cross-tabulation and descriptive statistics. The results of this study found that the majority of Morodemak fisher use environmentally unfriendly fishing gear such as sodo, large trawls, especially small trawls. The use of environmentally unfriendly fishing gear by the majority of fisher certainly damages the marine ecosystem, but the fishing gear is still considered effective for obtaining abundant catches that affect the welfare of fisher.

Integration of citizen science and eDNA reveals novel ecological insights for marine fish conservation

AbstractIn the face of climate change, the accelerating nature crisis, and other anthropogenic impacts, conserving biodiversity demands effective monitoring. While innovative approaches have emerged to enhance biodiversity assessment, significant data gaps persist, particularly within marine ecosystems. In this study, we assess the utility of combining citizen (community) science with environmental DNA (eDNA) metabarcoding for characterizing and quantifying marine fish biodiversity. Over the summer of 2022, 32 volunteers conducted extensive water sampling in a large Norwegian fjord, yielding 96 samples. Contrasting eDNA findings with conventional observational surveys (such as a national species registration database and beach seine surveys) unveiled a substantial overlap in recorded species inventories. The eDNA citizen science initiative identified previously undocumented species and rediscovered others emphasizing an increase in warm‐water species within the study area. Additionally, eDNA data unveiled reduced diversity within the inner fjord relative to the outer fjord. To conclude, our study demonstrates the successful integration of eDNA within a citizen science framework, facilitating comprehensive biodiversity tracking across coastal marine regions. These findings hold promise for advancing marine conservation efforts by providing valuable data to inform critical decision‐making processes.

Understanding bottom and surface marine heatwaves along the continental shelf of China

Marine heatwaves (MHWs) have become longer and more frequent over the past century under anthropogenic climate change, with devastating impacts on marine ecosystems. Surface MHWs (SMHWs) and their drivers have been extensively studied using satellite sea surface temperature data, yet the mechanism and characteristics of subsurface MHWs, especially bottom MHWs (BMHWs) along continental shelves, remain unclear. Based on a high-resolution ocean reanalysis dataset, we compare SMHWs and BMHWs along the continental shelf of China and find that BMHWs are typically longer (0–16 d) and more intense (0 °C–50 °C days) than SMHWs. The categorizing of both the BMHW and SMHW shows that moderate and strong events commonly occur in most areas with relatively large spatial coverage, whereas severe and extreme events occur with relatively small spatial coverage. There is a clear negative relationship between the BMHW intensity and ocean depth along the continental shelf, while the BMHW annual days and ocean depth are positively correlated in the Bohai and East China Seas. Generally, BMHWs and SMHWs occur more frequently in shallow coastal regions where the mixed layer depth is more likely to extend to the seafloor, resulting in high BMHW and SMHW synchrony. In addition to spatial coherence, there is a good temporal correspondence between BMHWs and SMHWs across the continental shelf of China from 1993 to 2020.

Understanding marine litter origin in a coastal area: Can Gio beaches, Ho Chi Minh City, Vietnam, as the case study

To decrease the leakage of waste and harmful compounds into marine ecosystems, it is imperative to identify the source of marine litter and implement appropriate mitigation strategies. In this study, bottles and single-use containers presented at four beaches in Can Thanh Town, Can Gio District, Ho Chi Minh City were recorded the abundance, country of production, and lifetime from the manufacturing stamp date on the bottles and containers. Instead of collecting items and bringing them to the laboratory like most studies on marine litter, this study used the Mergin Maps application to record data. A total of 522 items were recorded during two surveys. The identification of litter sources has been made considerably more accessible by using trademarks and logos. Among the 60.5% of items with recorded brands, items with domestic production addresses (Vietnam) accounted for the most significant proportion (78.2% of items with brands). In addition, Thailand accounted for the most significant proportion of items originating from foreign countries. Lids and caps are essential for long-distance transportation. Epibionts and bite marks indicated that most bottles and containers drifted along the ocean currents in the area. Marine litter from beaches in Can Gio District originated mainly from waste drifting from rivers and oceans. This study not only illustrated where the waste came from but also provided insightful data that would support managers' decisions to illustrate where the waste came from and provided insightful data that would support managers' decisions to regulate and lessen marine litter in the area effectively.

Physical and chemical characterization of remote coastal aquifers and submarine groundwater discharge from a glacierized watershed

AbstractCoastal aquifers play an important role in marine ecosystems by providing high fluxes of nutrients and solutes via submarine groundwater discharge pathways. The physical and chemical characterization of these dynamic systems is foundational to understanding the extent and magnitude of hydrogeologic processes and their subsequent contributions to the marine environment. We describe a km‐scale experimental field site located in a glaciofluvial delta entering Kachemak Bay, Alaska. Our characterization applies geophysical (ERT and HVSR), hydrogeologic (grain size analyses, slug tests and tidal response analyses) and geochemical (major ions and stable water isotopes) methods to describe the complexity of coastal aquifers in proglacial environments currently experiencing rapid transformations. The hydrogeologic and geophysical techniques revealed thick (20–84 m) sediments dominated by sands and gravels and delineated zones of freshwater, brackish water and saltwater at both high and low tides within the subterranean estuary. Estimates of hydraulic conductivities via multiple approaches ranged from 2 to 250 m d−1, with means across the four methods within the same order of magnitude. Tidal response analyses highlighted a coastal aquifer in strong connection with the sea as evidenced by clear spring‐ and neap‐tidal signals within a proximal piezometric hydrograph. Geochemical sampling revealed coastal groundwaters as substantially enriched in solutes compared to proximal river samples with limited variability across seasons. A clear connection between the Wosnesenski River and the adjacent aquifer was also observed, with concentrated recharge from the river corridor during the meltwater season. This combination of approaches provides the basis for a conceptual model for coastal aquifer systems within the Gulf of Alaska and an upscaled mean daily yield of freshwater and solutes from the delta subsurface. Our findings are critical for subsequent numerical simulations of groundwater flow, tidal pumping and chemical reactions and transport in these understudied environments. This approach may be applied for low‐cost, large‐scale hydrogeologic investigations in coastal areas and may be particularly useful for remote sites where access and mobility are challenging.

Intercomparison of ocean temperature and circulation near the Galápagos islands in high-resolution models and observations

The mean structure and variability of the Equatorial Undercurrent (EUC) have important implications for upwelling, sea surface temperature (SST), and productivity in the ecologically vital Galápagos Cold Pool. Historically, global coupled climate model simulations have exhibited considerable biases in their simulation of the EUC due to the requirement of relatively high spatial resolution to represent its dynamics. Particularly in the eastern equatorial Pacific, models must also adequately resolve important topographic features to accurately simulate the regional circulation. Here, we examine the extent to which a high-resolution configuration of the NCAR Community Earth System Model (CESM) and a suite of models from the High-Resolution Model Intercomparison project (HighResMIP) adequately represent the regional ocean circulation and other important climatological features of the eastern equatorial Pacific such as the EUC and the associated temperature patterns defining the cold tongue/Galápagos Cold Pool complex. Comparisons with satellite SST and in situ velocity observations, and a high-resolution ocean reanalysis product, illustrate that the high-resolution configuration of the CESM captures many key aspects of the SST field and EUC uniquely well, including its seasonal-to-interannual variability in the eastern equatorial Pacific. Specific strengths and biases of this model with direct comparison to the HighResMIP ensemble are discussed in detail, along with the potential for application of these models to interdisciplinary research topics such as projecting climate change impacts on marine ecosystems.

Environmental control and metabolic strategies of organic-matter-responsive bacterioplankton in the Weddell Sea (Antarctica).

Heterotrophic microbial communities play a significant role in driving carbon fluxes in marine ecosystems. Despite their importance, these communities remain understudied in remote polar oceans, which are known for their substantial contribution to the biological drawdown of atmospheric carbon dioxide. Our research focused on understanding the environmental factors and genetic makeup of key bacterial players involved in carbon remineralization in the Weddell Sea, including its coastal polynyas. Our experiments demonstrated that the combination of labile organic matter supply and temperature increase synergistically boosted bacterial growth. This suggests that, besides low seawater temperature, carbon limitation also hinders heterotrophic bacterial activity. Through the analysis of metagenome-assembled genomes, we discovered distinct genomic adaptation strategies in Bacteroidia and Gammaproteobacteria, both of which respond to organic matter. Both natural phytoplankton blooms and experimental addition of organic matter favoured Bacteroidia, which possess a large number of gene copies and a wide range of functional membrane transporters, glycoside hydrolases, and aminopeptidases. In contrast, the genomes of organic-matter-responsive Gammaproteobacteria were characterized by high densities of transcriptional regulators and transporters. Our findings suggest that bacterioplankton in the Weddell Sea, which respond to organic matter, employ metabolic strategies similar to those of their counterparts in temperate oceans. These strategies enable efficient growth at extremely low seawater temperatures, provided that organic carbon limitation is alleviated.

Fugacity- and biotransformation-based mechanistic insights into the trophic transfer of organophosphate flame retardants in a subtropical coastal food web from the Northern Beibu Gulf of China

The bioaccumulation and trophic transfer of organophosphate flame retardants (OPFRs) in marine ecosystems have attracted great attention in recent research, but our understanding of the trophic transfer mechanisms involved is limited. In this study, we investigated the trophodynamics of OPFRs and their metabolites in a subtropical coastal food web collected from the northern Beibu Gulf, China, and characterized their trophodynamics using fugacity- and biotransformation-based approaches. Eleven OPFRs and all 7 metabolites were simultaneously quantified in the shellfish, crustacean, pelagic fish, and benthic fish samples, with total concentrations ranging from 164–4.11 × 104 and 4.56–4.28 × 103 ng/g lipid weight, respectively. Significant biomagnification was observed only for tris (phenyl) phosphate (TPHP) and tris (2-ethylhexyl) phosphate (TEHP), while other compounds except for tris(2-chloroethyl) phosphate (TCEP) displayed biomagnification trends based on Monte Carlo simulations. Using a fugacity-based approach to normalize the accumulation of OPFRs in biota to their relative biological phase composition, storage lipid is the predominant biological phase for the mass distribution of 2-ethylhexyl diphenyl phosphate (EHDPHP) and TPHP. The water content and structure protein are equally important for TCEP, whereas lipid and structure protein are the two most important phases for other OPFRs. The mass distribution of these OPFRs along with TLs can explain their trophodynamics in the food web. The organophosphate diesters (as OPFR metabolites) also displayed biomagnification trends based on bootstrapped estimation. The correlation analysis and Korganism-water results jointly suggested the metabolites accumulation in high-TL organisms was related to biotransformation processes. The metabolite-backtracked trophic magnification factors for tri-n-butyl phosphate (TNBP) and TPHP were both greater than the values that accounted for only the parent compounds. This study highlights the incorporation of fugacity and biotransformation analysis to characterize the trophodynamic processes of OPFRs and other emerging pollutants in food webs.

A global multi-indicator assessment of the environmental impact of livestock products

Driven by a growing and more affluent population, changing diets and lifestyles, the demand for livestock products is expected to surge in the next decades. Satisfying this demand will result in additional pressures on land systems. The increasingly globalized supply chains of the livestock economy will further decouple many of these impacts from the places where livestock are reared. In this study, we determined the impact intensities of global livestock production across three environmental indicators: deforestation, biodiversity loss and marine eutrophication. To this end, we used global data on the production of crops (and grass), their trade and use as feed in livestock-production systems, as well as livestock production data. We found the highest deforestation and biodiversity impact intensities in the tropics in Central and South America, Southeast Asia and Central Western Africa. In contrast, the highest values for marine eutrophication intensities were found in countries located in Northern Europe and in South and in East Asia. Our analyses show differences caused by varying efficiencies in livestock production systems and by the sourcing patterns of feed items. In grazing systems for the production of ruminant meat, for example, the resulting impact intensities are dominated by the consumption of grass. In intensive and industrialized production systems, the bulk of the deforestation and, to a lesser extent, biodiversity impacts are linked to imported soybean feed. Our results can help identify livestock production systems and countries that would qualify as priority action targets, as well as potential entry points to make their livestock production systems more sustainable. They can also be used to assist consumers in comparing impacts across and within livestock food product types. Ultimately, understanding the environmental impacts embodied in global supply chains of livestock products can help create better regulatory policies and science-based interventions for protecting terrestrial and marine ecosystems.