Search Results (299)

Mercury (Hg) bioaccumulation in freshwater fish represents a major pathway of human exposure, particularly in cascade reservoir systems where hydrological retention and legacy contamination can enhance methylmercury (MeHg) formation and trophic transfer. This study quantified total mercury (THg) concentrations in seven tissues of seven fish species from the Arda River cascade (Bulgaria). Multi-tissue measurements were integrated with morphometric predictors, multivariate statistical analyses, and combined deterministic and probabilistic human-health risk assessments. Muscle and liver contained the highest THg concentrations, whereas gills and gonads exhibited the lowest levels. Predatory species and larger individuals accumulated significantly more Hg, reflecting trophic magnification and size-dependent exposure. A longitudinal gradient across the cascade reservoirs suggests hydrological retention effects influencing mercury distribution. Species- and tissue-specific size–Hg relationships further indicate heterogeneous bioaccumulation dynamics among taxa. Risk assessment indicated acceptable exposure for adults and pregnant women at average consumption (140 g·week⁻¹), but elevated exposure for children consuming high-Hg predators. Monte Carlo simulations (N = 30,000) revealed upper-tail risks, while Safe Weekly Intake thresholds provided species-specific consumption limits. These findings highlight the value of integrating multi-tissue monitoring with probabilistic risk modelling to support evidence-based fish-consumption advisories in contaminated freshwater systems. Full article

Lakes on the Inner Mongolia–Xinjiang Plateau (IMXP) are increasingly vulnerable to eutrophication under climate change and human pressure, yet long-term monitoring remains limited by sparse field sampling. Here, we reconstruct multi-decadal trophic dynamics across the IMXP using Landsat time series and temporally transferable machine-learning models and further quantify the underlying natural and anthropogenic drivers. We compiled monthly in situ water-quality observations (chlorophyll-a, Chl-a; total phosphorus, TP; total nitrogen, TN; Secchi depth, SD; and permanganate index, COD_Mn;) and calculated the trophic level index (TLI). After rigorous quality control and monthly aggregation, we compiled a dataset of 1345 matched lake–month samples spanning 2000–2024, and divided it into a training set (n = 1076; ≤2019) and an independent test set (n = 269; 2020–2024) to evaluate temporal transferability. We utilized Google Earth Engine to generate monthly surface reflectance composites from Landsat 7 ETM+, Landsat 8 OLI, and Landsat 9 OLI-2. Four supervised regression algorithms—ridge regression (RR), support vector regression (SVR), random forest (RF), and eXtreme Gradient Boosting (XGBoost)—were trained to estimate TLI. On the independent test period, XGBoost performed best (R² = 0.780, RMSE = 3.290, MAE = 1.779), followed by RF (R² = 0.770, RMSE = 3.364), SVR (R² = 0.700, RMSE = 3.842), and RR (R² = 0.630, RMSE = 4.267); we then used XGBoost to reconstruct monthly and yearly TLI for 610 perennial grassland lakes from 2000 to 2024. From 2000 to 2024, the annual mean TLI (48–49) across the IMXP exhibited a statistically significant upward trend (slope = 0.0158 TLI yr⁻¹; 95% confidence interval (CI) = 0.0050–0.0267; p = 0.006). Meanwhile, spatial heterogeneity was distinct (TLI: 41.51–59.70). High values concentrated in endorheic and desert–oasis basins (e.g., Eastern Inner Mongolia Plateau, >51), whereas lower values characterized high-altitude regions (e.g., Yarkant River, <45). Overall, trends ranged from −0.49 to 0.51 yr⁻¹, increasing in 54% of lakes (15.6% significantly) and decreasing in 46% (15.4% significantly). Attribution analyses identified NDVI (33.92%) and temperature (21.67%) as dominant drivers (55.59% combined), followed by precipitation (13.99%) and human proxies (30.42% combined: population 10.66%, grazing 10.31%, built-up 9.45%). Across 53 sub-basins, NDVI was the primary driver in 28, followed by temperature (11), population (7), precipitation (3), grazing (3), and built-up land (1); notably, the top two drivers explained 56.6–87.1% of variations. TWFE estimates revealed bidirectional NDVI effects (significant in 31/53): positive associations in 22 basins were linked to nutrient retention, contrasting with negative effects in nine basins associated with agricultural return flows. Temperature effects were significant in 15 basins and predominantly negative (14/15), except for the Qiangtang Plateau. Overall, eutrophication risk across the IMXP lake region reflects the combined influences of climatic conditions, vegetation conditions, and human activities, with their relative contributions varying among basins. Full article

This study presents integrated Cladoceran, plant macrofossil and diatom-based environmental reconstruction from the Čepkeliai Bog (Southern Lithuania), covering the Late Glacial–Early Holocene transition. The objective was to assess palaeoenvironmental changes with a focus on trophic state, acidification, and water-level fluctuations and to explore the applicability of these assemblages as temperature-sensitive indicators. The findings of our study revealed that sedimentation started at about 13,200–13,000 cal yr BP in a deep, oligotrophic and cold-water palaeobasin. Inferred palaeoenvironment changes correlate with the GI-1b event (Gertsenzee oscillation). A significant ecological shift to a shallow, warm, ecologically diverse environment occurredat about 13,000 cal yr BP and is consistent with the GI-1a (Allerød) period. The Younger Dryas (12,850–11,650 cal yr BP) is characterised by a rise in lake level and oligo-mesotrophic and high-water transparency conditions. At the end of the Younger Dryas (around 12,000 cal yr BP), climate warming and a drop in water levels were recorded. Intensive palaeobasin swamping processes began around 9700 years cal yr BP, during the Boreal period. A short-lived “9.2” cooling event was fixed at about 9200–9000 cal yr BP. The results obtained provide new insights into postglacial palaeoenvironmental dynamics in the southeastern Baltic region. Full article

Marine mesozooplankton (0.2–20 mm), as a critical trophic link between primary producers and higher trophic levels, are pivotal drivers of trophic cascades regulating pelagic ecosystem structure and function. This review synthesizes recent advances in understanding mesozooplankton-mediated trophic cascades (MMTC), with a focus on selective feeding mechanisms, and presents an original, integrated quantitative framework that fills gaps in quantification and prediction of MMTC. This framework includes the following: a dual-pathway conceptual model distinguishing density-mediated and trait-mediated cascades; a three-level grazing rate correction model addressing long-standing underestimations of mesozooplankton direct grazing rate on phytoplankton; a comprehensive Cascade Strength Index for quantifying cascade intensity; an extended numerical model—NPMZ model (Nutrient–Phytoplankton–Microzooplankton–Mesozooplankton) for simulating MMTC dynamics and their biogeochemical impacts. The review further elucidates the spatiotemporal heterogeneity of MMTC and its implications for plankton community size structure and biological carbon pump efficiency. It also systematically assess the combined impacts of global change drivers (ocean warming, acidification, eutrophication) on MMTC and their ecological consequences. This review advances the theoretical framework of marine trophic cascade research by establishing a unified quantitative paradigm for MMTC and provides mechanistic insights and predictive tools for understanding how climate change modulates pelagic food web dynamics and marine ecosystem services. Moreover, the proposed integrated research paradigm combining molecular tools, multi-factor experiments, and high-resolution numerical modeling offers a critical roadmap for future MMTC research in the Anthropocene. This provides a scientific basis for the conservation and adaptive management of marine ecosystems under global change. Full article

Microplastic pollution has become widespread in aquatic ecosystems worldwide; however, its consequences for ecosystem service provision and fisheries’ long-term sustainability remain poorly integrated across scientific disciplines. While previous reviews have primarily focused on sources, distribution patterns, and toxicological responses, this review advances the field by synthesizing existing evidence through an ecosystem-service framework. Specifically, it integrates organism-level biological responses with population dynamics and fishery productivity to evaluate how microplastic exposure may influence provisioning, regulating, and supporting services. It also critically provides patterns of sublethal effects, trophic transfer dynamics, and interactions with co-stressors. Particular attention is given to the challenge of scaling from physiological responses to measurable impacts on biomass production, recruitment stability, and habitat functionality. To clarify these linkages, the review provides a structured synthesis of service pathways connecting microplastic exposure to fishery-relevant outcomes and highlights priority research gaps necessary for quantitative risk assessment. In conclusion, advancing sustainability assessments requires long-term, field-based integration of ecotoxicology, population modeling, and ecosystem process metrics. By reframing microplastic pollution within a service-delivery context, this review offers a focused analytical foundation for evaluating its significance to sustainable fisheries and aquatic resource governance. Full article

Monoenoic fatty acids (MUFAs), defined by the presence of a single carbon–carbon double bond within a long aliphatic chain, constitute a structurally diverse and ecologically significant class of lipids widely distributed in aquatic organisms. In marine and freshwater environments, MUFAs are fundamental components of membrane phospholipids and storage lipids, where mono-unsaturation modulates melting point, lipid packing, and bilayer dynamics, enabling homeoviscous adaptation to fluctuations in temperature, pressure, salinity, and oxygen availability. Positional and geometric isomerism (e.g., cis-Δ5, Δ7, Δ9, Δ11, Δ13, and trans forms) further enhances biochemical diversity, providing sensitive chemotaxonomic markers and indicators of trophic transfer across food webs. In addition to common straight-chain monoenes, rare methyl-branched, cyclopropane-containing, and acetylenic derivatives occur in specialized aquatic taxa, reflecting evolutionary adaptation and ecological niche differentiation. Computational QSAR analyses suggest that monoenoic fatty acids and their unusual analogues occupy bioactivity spaces associated with lipid metabolism regulation, vascular and inflammatory modulation, antimicrobial defense, and membrane stabilization. This review integrates structural chemistry, biosynthesis, ecological distribution, trophic dynamics, and predicted biological activity of monoenoic fatty acids in aquatic systems, highlighting their dual role as adaptive membrane constituents and as biologically active mediators linking molecular lipid architecture to hydrobiological function and environmental change. Full article

Kelp transplantation is a nature-based strategy aimed at restoring coastal habitat integrity and marine biodiversity. However, its functional consequences for trophic integration within benthic food webs remain poorly understood. Using δ¹³C and δ¹⁵N stable isotope analyses, we evaluated how Undaria pinnatifida transplantation alters consumer trophic structures and isotopic niche characteristics in Oeyeondo, South Korea. While basal source remained isotopically uniform across sites, the introduction of U. pinnatifida triggered significant isotopic shifts in consumers, reflecting a reorganization of carbon assimilation pathways. At the transplanted site, herbivores exhibited significantly enriched δ¹³C values (−14.7 ± 2.0‰ to −13.2 ± 0.3‰) compared to the control site (−19.3 ± 1.2‰), indicating direct assimilation of kelp-derived carbon. Conversely, grazers showed depleted δ¹³C values (−20.6 ± 0.6‰) reflecting a shift toward alternative benthic resources. Isotopic niche metrics revealed a broader community-level niche width at the transplanted site, driven by increased resource diversity and niche partitioning. These findings demonstrate that kelp transplantation effectively restructures benthic food web dynamics by providing new energy pathways, offering a robust functional framework for evaluating marine forest restoration success. Full article

This study evaluates the ecological impact of Robinia pseudoacacia L. (black locust) invasion on native chestnut (Castanea sativa Mill.) groves on Mount Amiata (Central Italy), focusing on both plant and macrofungal community dynamics. Surveys were conducted over a three-year period (2022–2024) across 16 plots to assess shifts in taxonomic alpha diversity, species richness, and trophic guild structure. Our results demonstrate that while R. pseudoacacia stands exhibit a higher Shannon–Wiener index for plants, native chestnut groves host significantly greater species richness and higher taxonomic distinctiveness across both biological groups. A major shift in fungal functional structure was observed with chestnut-dominated plots characterized by a predominance of ectomycorrhizal species (58.3%), whereas invaded stands were heavily dominated by saprotrophic fungi (73.4%). Non-metric Multidimensional Scaling (NMDS) further confirmed a clear separation in community composition between the two forest types, indicating that R. pseudoacacia invasion leads to a homogenization of the forest biota and a potential decline in ecosystem health, as evidenced by the sharp reduction in mycorrhizal diversity. These findings highlight the importance of monitoring macrofungal communities as sensitive bioindicators of the ecological degradation caused by invasive woody species. Full article

Controlled-environment agriculture (CEA) and circular production systems require coordinated monitoring of biological and physicochemical processes across trophic levels. This project report presents the implementation of a multi-trophic controlled-environment agriculture demonstrator that integrates computer-vision-based monitoring with established sensor infrastructure for aquaculture, poultry, plants, microalgae, duckweed, and insect modules. Stereo imaging and RGB-D systems are deployed for non-invasive quantification of fish biomass and plant growth, while continuous water-quality and environmental measurements (e.g., pH, dissolved oxygen, nitrate, ammonium, temperature, CO₂) provide complementary process data. These data streams are synchronized within a shared database architecture to enable cross-module evaluation of nutrient dynamics, growth progression, and operational stability under real facility conditions. The implemented framework demonstrates how computer vision can extend conventional sensor-based monitoring by directly capturing biological performance indicators across aquatic, terrestrial, and microbial domains. While advanced predictive modeling and full digital twin simulation remain future development steps, the realized data-integration architecture establishes a structural foundation for the systematic evaluation of circular indoor food-production systems. The demonstrator illustrates how multimodal monitoring can support nutrient recirculation, transparency of biological variability, and data-driven assessment within controlled multi-trophic environments. Full article

Greenhouse gas emissions associated with plastic production and disposal span the entire plastic life cycle, establishing a direct link between plastic pollution and climate change. This review demonstrates that micro- and nanoplastics (MNPs) also function as active components of climate feedback systems by disrupting marine trophic structures, altering microbial assemblages, and diminishing the ocean’s capacity for carbon storage. Synthesized evidence further indicates that environmental degradation of polymers enhances surface reactivity, facilitating the sorption and transport of persistent contaminants, including per- and polyfluoroalkyl substances (PFAS) and antibiotic-resistant bacteria (ARB). These interactions amplify combined risks to ecosystems and public health under climate change scenarios. This review also reveals that many existing remediation strategies prioritize waste reduction or physical removal while failing to account for contaminant–plastic–climate interactions, thereby limiting their long-term effectiveness. By integrating climate-related processes, polymer transformation, and contaminant dynamics, this review identifies critical knowledge gaps and underscores the need for mitigation strategies that jointly address plastic pollution, climate feedbacks, and emerging public health threats. Full article

Phthalate esters (PAEs), ubiquitous plastic additives, have emerged as persistent contaminants in aquatic ecosystems, yet their propagation from molecular initiating events to ecosystem-level collapse remains poorly integrated. This review synthesizes current knowledge on the source-to-sink dynamics of PAEs, revealing a critical paradox in their bioaccumulation patterns: unlike classical persistent organic pollutants, high molecular weight PAEs exhibit distinct trophic dilution rather than biomagnification along food webs, driven by metabolic biotransformation in higher trophic organisms. Despite this dilution, PAEs trigger a bottom-up toxicity cascade. Driven by molecular initiating events, PAEs induce a range of adverse effects at the individual level, including immunotoxicity, neurotoxicity, endocrine disruption, metabolic dysfunction, and trans-trophic oxidative stress. Crucially, prolonged exposure drives epigenetic reprogramming, which reduces reproductive output, thereby threatening long-term population recruitment. These individual and population deficits could escalate into higher ecological consequences, specifically by diminishing benthic biological control over phytoplankton, dampening energy transfer efficiency, and simplifying community structure, thereby posing a potential threat to primary productivity and aquatic ecosystem sustainability. Despite recent advances, critical knowledge gaps remain, particularly regarding their cascading impacts on ecosystem services, as well as synergistic interactions between PAEs and other contaminants. In order to validate laboratory results with actual ecological risk assessments, future research should incorporate multi-scale models and quantitative adverse outcome Pathways as well as their synergistic interactions between PAEs and other contaminants, and advanced in vitro systems such as organoids. Resolving these issues is essential to reducing the risks that PAEs pose to aquatic environments. Full article

Utah Lake is a large, shallow, highly eutrophic system that is naturally rich in phosphorus (P) and is prone to harmful algal blooms (HABs). While ongoing regulatory efforts often focus on reducing external anthropogenic P loads, particularly from wastewater treatment plants (WWTPs), accumulating evidence suggests that internal sediment P cycling and atmospheric deposition (AD) govern water column P concentrations and are the primary drivers of the lake’s trophic state. We synthesize the existing literature and present new data to demonstrate that (1) the lake’s P-rich, geologic sediments buffer the water column, rendering it largely insensitive to major changes in anthropogenic P inputs due to sorption dynamics, and (2) AD alone provides sufficient P to sustain the lake’s eutrophic status. New analyses on previous AD measurements combined with new active dust sampling data reinforce these conclusions by demonstrating no attenuation of dust deposition to the interior of Utah Lake. We conclude that efforts focused solely on limiting P inputs will have minimal impact on lowering the water column P concentration or improving the lake’s water quality, and that alternative physical and biological restoration methods, such as carp removal and shoreline restoration, are likely to be far more effective. Full article

The Atlantic blue crab (Callinectes sapidus) has rapidly expanded across the Mediterranean Sea, forming self-sustaining populations in coastal and transitional ecosystems. Its ecological plasticity, high reproductive potential, and tolerance to wide salinity and temperature ranges have enabled a rapid basin-wide colonization, particularly evident in Italian lagoons and estuaries. This invasion has generated substantial ecological alterations, such as predation on bivalves, competition with native decapods, and disruptions of trophic dynamics, as well as significant economic losses for fisheries and aquaculture sectors, especially in northern Adriatic clam-farming areas. Social perceptions vary widely, and management actions remain fragmented, limiting the effectiveness of control and mitigation efforts. This review analyzes the scientific and gray literature published from its first Mediterranean records to 2025, synthesizing evidence on the species’ distribution, ecological impacts, socio-economic consequences, and existing regulatory responses, with a focus on the Mediterranean basin and Italy. Studies on consumers’ and fishers’ perceptions are examined to identify emerging opportunities for sustainable utilization. By integrating ecological and socio-economic dimensions, the review outlines priority knowledge gaps and management needs, providing a science-based framework to support coordinated monitoring, adaptive control strategies, and potential valorization pathways consistent with the EU Green Deal, the Blue Economy, and Circular Bioeconomy principles. Full article

The rapid increase in the world’s human population has largely been attributed to efforts aimed at enhancing primary productivity and enriching food resources. However, an intriguing proposition of M. Rosenzweig, known as the paradox of enrichment, challenged the notion that such enrichment schemes always lead to sustained population growth. Instead, they can disrupt the delicate equilibrium of predator–prey systems, potentially driving one or both species to extinction. In this study, we develop a comprehensive mathematical framework that unifies Rosenzweig’s six analytical models of trophic exploitation through the Richards growth model, which can be viewed as a Box–Cox transformation of one species’ abundance relative to carrying capacity. Our analysis not only elucidates the connections and similarities between each model but also presents a generalized framework that unveils the underlying relationships between the proposed functions. Using the generalized logarithm and exponential functions of nonextensive statistical mechanics, we offer a fresh perspective and highlight the importance of a cautious approach when enriching ecosystems. This unification clarifies how the parameters that govern growth dynamics and predator–prey interactions determine system stability in diverse ecological contexts. Through numerical simulations and isoclinic analysis, we demonstrate that our generalized model accurately reproduces the classic paradox of enrichment while providing new insights into the mechanisms driving population fluctuations after environmental enrichment. This mathematical synthesis advances both theoretical ecology and practical conservation efforts by enabling a more accurate assessment of enrichment risks in managed ecosystems. Full article

Transitional water bodies are coastal areas of strategic naturalistic and socio-economic importance, and highly vulnerable to increased anthropic pressure. A monitoring study was performed in the transitional area of Lake Faro (Cape Peloro Lagoon, Italy), where specimens of the threatened species Pinna nobilis (Mollusca, Bivalvia) constitute a resident community, as a part of a wider research program aiming to preserve this organism in the context of safeguarding lake biodiversity. Five surface water samplings with a two-month frequency were carried out at four selected stations, three of which were located in the inner part of the lake and one control station outside, in a canal connecting the lake to the Messina Straits. Trophic conditions (total suspender matter, nutrients and chlorophyll-a) and the main environmental variables (temperature, salinity, dissolved oxygen) were measured. Insights into the total prokaryotic abundance and metabolism via the extracellular enzymatic activities (i.e., leucine aminopeptidase; beta-glucosidase and alkaline phosphatase) were obtained. The dataset indicated that microbial and trophic dynamics were associated with the abundance of the P. nobilis population. These parameters, moreover, proved to represent a suitable tool for characterizing the environmental health status of transitional areas, as well as for implementing new effective strategies for sustainable resource management. Full article