Spatial and temporal variability in δ13C and δ15N signatures of three habitat-forming kelps in the coastal upwelling system of central Chile.

Ocean acidification reduces diatom and photosynthetic gene abundance on plastic in an coastal bay mesocosm experiment.

Marine microplastic pollution presents a critical environmental challenge, affecting ecosystems, wildlife, and human health as millions of tons of plastic waste enter oceans each year. Microplastics, due to their small size, are difficult to detect and accumulate widely in marine environments, where they integrate into the food web. Artificial Intelligence (AI) offers promising advancements for modeling, detecting, and mitigating the effects of microplastics in marine ecosystems. This narrative review examines recent developments in AI applications for addressing microplastic pollution. The review focuses on AI-driven modeling for predicting microplastic flows, intelligent waste detection systems that utilize remote sensing and autonomous robotics, and AI-based interventions aimed at reducing microplastic release. AI-driven models enhance the accuracy of predicting microplastic accumulation zones, supporting targeted clean-up efforts and informed policy-making. Advanced detection systems provide real-time monitoring over extensive areas, while AI-based filtration and material innovation technologies help reduce microplastic pollution at the source. AI holds significant potential to mitigate marine microplastic pollution, yet challenges such as data availability, model refinement, and global collaboration remain. Future research should focus on enhancing AI models, refining detection systems, and encouraging international data-sharing and cooperation. Collaboration across sectors is essential to fully leverage AI's potential in safeguarding marine ecosystems from microplastic pollution.

Although considered emerging contaminants and critical raw materials, the biogeochemical behavior of geogenic and anthropogenic rare earth elements and yttrium (REY) in freshwater systems remains poorly constrained. Here we provide high-quality, multi-trophic REY data from two freshwater ecosystems along the Rhine River, one impacted by anthropogenic REY and one unaffected. Similar to previous studies on estuarine and marine systems, REY concentrations decrease with trophic level, necessitating matrix separation and preconcentration to provide high-quality REY data for ultralow-concentration samples. Among fish tissues, gills and livers show the highest REY concentrations, consistent with detoxification and/or sequestration functions. Additionally, these large concentration differences between and within biota highlight the need to thoroughly record baseline REY levels in natural ecosystems. Despite differences in REY concentration, shale-normalized REY patterns are closely similar across organisms, suggesting that REY signatures are largely conserved along the food web. This allows them to be used for biogeochemical fingerprinting. While the anthropogenic Gd from macrocyclic contrast agents in the Rhine River it is not bioavailable, the anthropogenic La derived from the production of fluid catalytic cracking catalysts is taken up by organisms and can be traced along the food chain. Mussel shells record temporal changes of La levels in ambient water, making them promising long-term bioarchives for REY monitoring and contamination tracking.

Mercury bioaccumulation and biomagnification in southern hemisphere riverine food webs: Environmental drivers across a 3,700km Chilean latitudinal gradient.

Harmful algal blooms (HABs) release toxic compounds in water and are increasing in frequency worldwide due to eutrophication. HABs in Lake Erie are monitored extensively, but the neurotoxin β-methylamino-L-alanine (BMAA) has not been fully characterized in this system. Our objectives were to determine the presence of BMAA and its isomers, N-(2-aminoethyl) glycine (AEG), 2,4-diaminobutyric acid (DAB), and β-amino-N-methylalanine (BAMA), in Lake Erie organisms and the possibility of toxin biomagnification. We sampled zooplankton, mussels, forage fish, adult yellow perch, and adult walleye near Point Pelee, Ontario, Canada, and quantified their trophic positions. BMAA and its isomers were quantified using liquid chromatography with tandem mass spectrometry in zooplankton, mussels, and fish samples, and trophic position was quantified using nitrogen stable isotope analysis in whole invertebrate samples and fish muscle tissue. BMAA was detected in 26% of samples tested, while AEG, DAB, and BAMA were detected in 90.6%, 48%, and 71.3% of the samples, respectively. AEG, DAB and BAMA were detected in zooplankton, mussels, and fish. BMAA was detected in brains of forage fish and yellow perch but not walleye, zooplankton or mussels. Isomer concentrations varied across adult fish tissues, and species differences were also observed in the brain. A positive relationship between trophic position and brain DAB concentration provided some support for toxin biomagnification in this food web. However, the relationship was not maintained when considering only fish, highlighting that the evidence of DAB biomagnification is not strong. Our findings show that isomers of BMAA may represent a greater risk to aquatic wildlife than BMAA itself and raise questions about organismal exposure route and metabolism of these toxins.

Multigenerational adaptation alters methylmercury uptake in cyanobacteria under warming and elevated CO2.

The role of cumaceans (Crustacea) in the marine food webs: A review

Rare earth elements (REEs) are increasingly recognized as emerging contaminants, yet field data remain scarce for tropical marine ecosystems and for seabird matrices beyond feathers. Here, we present a multi-matrix assessment of REEs across a tropical oceanic-coastal gradient in the South Atlantic, including, to our knowledge, the first measurements of REEs in seabird blood and eggs. We analyzed 311 samples including brown booby (Sula leucogaster) blood, feathers and eggs, fish muscle and liver, and crab muscle from a remote oceanic archipelago (SPSPA) and a nearshore coastal archipelago (Santana). ΣREE in seabird samples differed among matrices, with feathers generally showing higher median values than blood and eggs, underscoring matrix-specific integration of exposure. Spatial patterns were also matrix- and age-dependent: blood ΣREE showed no consistent site contrast, feather differences between sites were largely restricted to juveniles, and eggs showed higher ΣREE at Santana, indicating that maternal transfer provides a clear pathway for expressing site-specific exposure signals. In fishes, interspecific differences were detected at SPSPA in both liver and muscle, whereas no among-species difference was detected for muscle at Santana; liver often exceeded muscle, consistent with tissue-dependent accumulation. A screening-level dietary assessment indicated negligible carcinogenic risk from ΣREE exposure via edible fish muscle under adult and child scenarios, with intake distributions far below the provisional tolerable daily intake and zero exceedance probability. Overall, these results expand baseline REE knowledge for tropical marine food webs and highlight seabird eggs as a sensitive matrix for spatial comparisons.

Bioaccumulation, trophic transfer and suspect screening for methoxylated brominated compounds in a tropical marine food web.

Evaluation of seasonal variations in energy sources and trophic positions of Calanus sinicus and Euphausia pacifica in the central-eastern Yellow Sea using bulk and compound-specific stable isotope analyses.

Mangrove ecosystems are among the most productive coastal habitats and serve as key nursery zones for fish eggs and larvae (ichthyoplankton). While seasonal variation in ichthyoplankton has been relatively well studied, the impacts of extreme climate events remain poorly understood. This perspective paper presents a narrative literature review and interpretative synthesis of 80 studies at a global scale on mangrove ichthyoplankton. We identified general ecological patterns and potential effects of climate-driven disturbances on fish eggs and larvae. Four main research themes emerged: seasonal variation (63 studies), human-induced changes in ichthyoplankton dynamics (7 studies), advances in identification through molecular versus morphological approaches (8 studies), and impacts of climate change (2 studies). Seasonal variation dominated the literature, whereas human-induced effects were mostly reported in Malaysian mangroves. Human impacts approaches provided insights into larval resilience to pollution, including microplastics. Only a few studies directly addressed climate extremes. Research on the consequences of extreme climatic extremes in mangrove-ecosystems suggest that, by altering water quality and habitat integrity, these events probably compromise the nursery function of mangroves and affect fisheries and estuarine food webs. Despite their ecological importance, the lack of long-term studies limits understanding of climate extremes on mangrove ichthyoplankton. Future research should include long-term monitoring, predictive modeling, and molecular tools to assess resilience. Strengthening research in this field is essential for designing conservation strategies that maintain mangroves as nurseries and support fisheries and coastal livelihoods under global climate change.

Cigarette butts constitute the most ubiquitous plastic litter worldwide, serving as a persistent source of microplastic fibers and toxic chemical leachates in terrestrial and aquatic ecosystems. Primarily made of cellulose acetate, discarded butts degrade slowly via physicochemical processes, liberating cigarette butt-derived microplastics alongside hazardous additives such as nicotine, heavy metals, and polycyclic aromatic hydrocarbons. This PRISMA-guided narrative review consolidates evidence on the environmental prevalence, transport, and fate of these microplastics, rigorously appraises progress in analytical detection methods, and evaluates their ecotoxicological impacts across food web levels. Studies reveal induction of behavioral changes, elevated mortality, and bioaccumulation in aquatic species, with particles functioning as carriers for persistent organic contaminants and metals. The review also addresses the considerable economic costs of cigarette butt pollution and scrutinizes mitigation options, including cutting-edge removal techniques, extended producer responsibility schemes, and circular-economy pathways such as cellulose acetate reclamation and composite sorbent fabrication. Persistent gaps exist in long-term degradation patterns, realistic exposure limits, and practical remediation efficacy, necessitating focused research to support evidence-based policies and sustainable waste management.

Health risks of exposure to organotin compounds via seafood consumption after their legal ban.

Microplastic ingestion in demersal and benthic species from the Portuguese coast: Scyliorhinuscanicula,Trisopterusluscus,Polybiushenslowii.

Mercury isotope dynamics in marine fish during bioaccumulation and excretion: Temporal responses across tissues.

Contemporary ecological networks reflect the influence of evolutionary and ecological processes on species interactions. Additionally, late Quaternary megafaunal extinctions and subsequent range contractions have interrupted mammalian predator–prey interactions to differing degrees among continents. However, the extent to which species losses have shaped geographic variation in the vertical and horizontal structure of contemporary mammalian food webs remains poorly understood. Furthermore, the relative influences of species loss, evolutionary history, and contemporary environmental drivers on the structure of mammalian food webs have not been tested. Here, we assembled mammal food webs for 389 sites throughout the Neotropics, Afrotropics, and Indomalaya. We first examined variation among continents in food web properties, including predator–prey richness ratios, predator generality, prey vulnerability, and predator dietary specialization. We found that Neotropical food webs bear imprints of severe species loss, featuring smaller predators, lower predator generality, higher prey vulnerability, and reduced prey species availability compared to Afrotropical food webs, in which most large mammals persisted. Furthermore, we reveal that multiple historical legacies, including community lineage history, paleoclimatic variability, mountain uplift, and species losses, as well as contemporary environmental variability, collectively predicted variation in predator dietary niche breadth within continents. Our findings offer unique perspectives on how trophic interactions within food webs respond to species losses and how macroevolutionary and macroecological processes have shaped the biogeography of contemporary mammal food webs.

Microbial eukaryotes play a vital role in biogeochemical cycles and aquatic food webs. Over past decades, their taxonomic diversity has been investigated using short-read DNA metabarcoding, which, while effective, is hampered by the limited resolution of the targeted regions. In this study, we utilised both short-read (Illumina) and long-read (PacBio) metabarcoding approaches to analyse eukaryotic diversity in a lake ecosystem over one year, allowing for a direct comparison of the results obtained from each method. Our metabarcoding analysis revealed a high degree of congruence between long-read and short-read data at broad taxonomic levels. However, at finer taxonomic scales, such as the genus level, long-read sequencing achieved higher resolution, enabling more precise identification of microbial eukaryotes. This enhanced taxonomic resolution proved especially valuable for tracking seasonal dynamics within key groups, including ciliates and chytrid fungi. The resolution offered by long-read sequencing provides a more detailed picture of the microbial eukaryotic community, thereby facilitating the exploration of ecological interactions at a finer scale. For example, this approach allowed us to monitor the dynamics of the chytrid genus Zygorhizidium in relation to various diatom genera, which are primary targets for chytrid parasitism.

Introduction High mountain streams are experiencing pronounced shifts in precipitation regimes and water chemistry; however, it remains unclear how organisms inhabiting these systems influence the transfer of chemical elements through food webs. Methods We measured concentrations of potassium and chlorine in algae, grazing mayflies, predatory stoneflies, and Alpine Bullhead ( Cottus poecilopus ) across seasons in an alpine stream. Results Algae exhibited marked seasonal variation, with higher potassium accumulation during the main summer growth period despite relatively stable water concentrations. Grazing mayflies maintained stable potassium levels but showed increased chlorine during colder months when chlorine concentrations in water were elevated. Predatory stoneflies showed only minor seasonal variation, with a slight increase in potassium in winter. The Alpine Bullhead did not exhibit significant seasonal changes in potassium or chlorine accumulation in its skull. Following major flood events, potassium and chlorine concentrations tended to co-vary across trophic levels, whereas under baseflow conditions they often varied independently. Discussion These patterns suggest that different trophic groups regulate element accumulation according to their physiology, life history, and ecological roles. The decoupling of organismal and water chemistry indicates that environmental concentrations alone do not fully explain element distribution within alpine stream food webs. Our findings provide new insights into element dynamics and highlight the importance of biological mediation in high-mountain ecosystems under changing environmental conditions.

This study is the first to quantify the prevalence of microplastics in field-collected mosquito larvae across distinct species in Shiraz, Iran, and to assess potential bioaccumulation risks, providing insights into the ecological impacts of microplastics (MPs). Using a stratified sampling approach, 721 mosquito larvae were collected from six locations in Shiraz. The MPs were characterized by optical microscopy and Raman spectroscopy, focusing on their quantity, size, morphology, and polymer type. Of the five representative mosquito species collected (Culex pipiens, Culiseta alaskaensis, Culex pusillus, Culex vagans, and Culex bitaeniorhynchus), all specimens selected at random tested positive for MPs, which were predominantly white (81%) and black (84%). Polyethylene was the most encountered polymer, especially in Culex pipiens and Culex pusillus, comprising 52.81% and 25.84% of the total MPs, respectively. These findings not only highlight the ubiquity of MPs in freshwater ecosystems but also suggest potential bioaccumulation risks within food webs. Given the environmental and health implications of MP contamination, further research is necessary to explore the ecological effects of MPs on mosquito vectors and their capacity for pathogen transmission.