Lakes and lake sediments are significant components of the global carbon (C) cycle, and may store very large amounts of organic matter. Carbon sequestration in lakes is subject to substantial temporal and spatial variation and may be strongly affected by human activities. Here, we report accumulation rates (AR) of organic C (OC), total nitrogen (TN) and total phosphorous (TP), and investigate their responses to anthropogenic impact over the past 150 years by analyzing 62 sediment cores from 11 shallow lakes in the Songnen Plain, northeast China. From the center of each of the lakes, we selected one master core for age determination by ²¹⁰Pb and ¹³⁷Cs radioisotopes. The contents of OC, TN, TP, dry bulk density and mass specific magnetic susceptibility were then determined for all cores. The regional OCAR, TNAR and TPAR up-scaling from the multiple cores yielded mean values of 51.63 ± 15.13, 2.50 ± 0.98, and 0.90 ± 0.21 g m⁻² yr⁻¹, respectively. Nutrient AR in the studied lakes increased by a factor of approximately 2 × from the middle 19th century to the 1950s, and approximately 5 × after the 1950s. Elemental ratios show that the increase in OCAR is mainly the result of C autogenesis from the growth of aquatic plants stimulated by agricultural intensification, including increased chemical fertilizer application and farmland expansion. Significantly enhanced nutrient burial by these lakes after the 1950s resulted from increased anthropogenic impacts in northeast China. More sustainable agricultural practises, including a decrease in P fertilizer use, would result in a lowering of OCAR, TNAR and TPAR in the future.

Despite the efforts of the European Commission to implement measures that offset the detrimental effects of agricultural intensification, farmland bird populations continue to decline. Pesticide use has been pointed out as a major cause of decline, with growing concern about those agro-chemicals that act as endocrine disruptors. We report here on the effects of flutriafol, a ubiquitous systemic fungicide used for cereal seed treatment, on the physiology and reproduction of a declining gamebird. Captive red-legged partridges (Alectoris rufa; n = 11–13 pairs per treatment) were fed wheat treated with 0%, 20% or 100% of the flutriafol application rate during 25 days in late winter. We studied treatment effects on the reproductive performance, carotenoid-based coloration and cellular immune responsiveness of adult partridges, and their relationship with changes in oxidative stress biomarkers and plasma biochemistry. We also studied the effect of parental exposure on egg antioxidant content and on the survival, growth and cellular immune response of offspring. Exposed partridges experienced physiological effects (reduced levels of cholesterol and triglycerides), phenotypical effects (a reduction in the carotenoid-based pigmentation of their eye rings), and most importantly, severe adverse effects on reproduction: a reduced clutch size and fertile egg ratio, and an overall offspring production reduced by more than 50%. No effects on body condition or cellular immune response of either exposed adult or their surviving offspring were observed. These results, together with previous data on field exposure in wild partridges, demonstrate that seed treatment with flutriafol represents a risk for granivorous birds; they also highlight a need to improve the current regulation system used for foreseeing and preventing negative impacts of Plant Protection Products on wildlife.

The attenuation and fate of erythromycin-resistance-methylase (erm) and extended-spectrum beta-lactamse (bla) genes were quantified over time in aquatic systems by adding 20-L swine waste to 11,300-L outdoor mesocosms that simulated receiving water conditions below intensive agricultural operations. The units were prepared with two different light-exposure scenarios and included artificial substrates to assess gene movement into biofilms. Of eleven genes tested, only erm(B), erm(F), blaSHV and blaTEM were found in sufficient quantity for monitoring. The genes disappeared rapidly from the water column and first-order water-column disappearance coefficients were calculated. However, detected gene levels became elevated in the biofilms within 2 days, but then disappeared over time. Differences were observed between sunlight and dark treatments and among individual genes, suggesting that ecological and gene-specific factors play roles in the fate of these genes after release into the environment. Ultimately, this information will aid in generating better predictive models for gene fate.

The Nanfei River was one of dominant inflowing rivers of the fifth largest freshwater Chaohu Lake in China, which had been subjected to increasing nutrients and contaminants from population expansion, rapid industrialization and agricultural intensification in recent decades. In present study, surface sediment from the Nanfei River was collected to investigate the anthropogenic impact on distribution and bioavailability of heavy metals. Possible Cd sources along the river were constrained by using Cd isotope signatures and labile concentrations of heavy metals in sediment were determined through the DGT technique for risk assessment. Results showed that Cd in river sediment showed greatest enrichment (EF 0.8–9.4), indicating massive pollution from anthropogenic activities. Among the various possible Cd source materials, urban road dust, industrial soil and chicken manure, displayed higher Cd abundance and enrichment that might contribute to Cd accumulation in river sediment. Cadmium isotopic composition in river sediment was ranged from −0.21 ± 0.01‰ to 0.13 ± 0.03‰, whereas yielded relative variation from −0.31 ± 0.02‰ to 0.23 ± 0.01‰ in source materials. Accordingly, Cd sources along the river were constrained, i.e. traffic and industrial activities in the upper and middle reaches whereas agricultural activities in the lower reaches. Furthermore, the evaluation on ecological risk of heavy metals in sediment on basis of SQGs and DGT-labile concentrations demonstrated that Pb and Zn might pose higher risk on aquatic species. The present study confirmed that Cd isotopes were promising source tracer in environmental studies.

Farmland birds are declining across Europe and North America and the research of factors behind is the subject of extensive researches. Agricultural intensification is now recognized as a major factor governing the loss of biodiversity with strong evidence that pesticides induced direct bird mortality at a high dose. However, less attention has been given to the long-term effects of chronic exposure to low dose of pesticides. Here, we used an experimental procedure in which grey partridges were fed with untreated grains obtained from either organic (no pesticide) or conventional agriculture (with pesticide) for 26 weeks, thus strictly mimicking wild birds foraging on fields. We then examined a suite of life-history traits (ecophysiological and behavioural) that may ultimately, influence population dynamics. We show for the first time that ingesting low pesticide doses over a long period has long-term consequences on several major physiological pathways without inducing differential mortality. Compared to control partridges, birds exposed to chronic doses i) had less developed carotenoid-based ornaments due to lower concentrations of plasmatic carotenoids, ii) had higher activated immune system, iii) showed signs of physiological stress inducing a higher intestinal parasitic load, iv) had higher behavioural activity and body condition and v) showed lower breeding investment. Our results are consistent with a hormetic effect, in which exposure to a low dose of a chemical agent may induce a positive response, but our results also indicate that breeding adults may show impaired fitness traits bearing population consequences through reduced breeding investment or productivity. Given the current scale of use of pesticides in agrosystems, we suggest that such shifts in life-history traits may have a negative long-term impact on wild bird populations across agrosystems. We stress that long-term effects should no longer be ignored in pesticide risk assessment, where currently, only short-term effects are taken into account.

Water pollution by pesticides used in agriculture is currently a major concern both in Spain and in Europe as a whole, prompting the need to evaluate water quality and ecological risk in areas of intensive agriculture. This study involved monitoring pesticide residues and certain degradation products in surface and ground waters of the Denomination of Origin (DO) Jumilla vineyard area in Spain. Sixty-nine pesticides were selected and evaluated at twenty-one sampling points using a multi-residue analytical method, based on solid-phase extraction (SPE) and analysis by liquid chromatography coupled with mass spectrometry (LC-MS), providing reliable results. Twenty-six compounds from those selected were detected in the samples analyzed (eleven insecticides including one degradation product, nine herbicides, and six fungicides) and fifteen of them were found in concentrations over 0.1 μg L⁻¹ (upper threshold established by the EU for pesticides detected in waters for human consumption). Indoxacarb was present in more than 70% of the samples, being the most frequently detected compound in water samples. Some pesticides were ubiquitous in all the water samples. Ecotoxicological risk indicators, toxic units (TUs) and risk quotients (RQs), for algae, Daphnia magna and fish were calculated to estimate the environmental risk of the presence of pesticides in waters. The compounds with the highest risk were the herbicides pendimethalin, with RQ values > 1 for the three aquatic organisms, and diflufenican, posing a high risk for algae and fish, and the insecticide chlorpyrifos, with a high risk for Daphnia magna and fish. The ∑TUi determined for water at each sampling point posed only a high risk for the three aquatic organisms in a sample. These results are important for considering the selection of pesticides with less environmental risk in intensive agricultural areas.

Reactive nitrogen (Nr) is an important driver of global change, causing alterations in ecosystem biodiversity and functionality. Environmental assessments require monitoring the emission and deposition of both the amount and types of Nr. This is especially important in heterogeneous landscapes, as different land-cover types emit particular forms of Nr to the atmosphere, which can impact ecosystems distinctively. Such assessments require high spatial resolution maps that also integrate temporal variations, and can only be feasibly achieved by using ecological indicators. Our aim was to rank land-cover types according to the amount and form of emitted atmospheric Nr in a complex landscape with multiple sources of N. To do so, we measured and mapped nitrogen concentration and isotopic composition in lichen thalli, which we then related to land-cover data. Results suggested that, at the landscape scale, intensive agriculture and urban areas were the most important sources of Nr to the atmosphere. Additionally, the ocean greatly influences Nr in land, by providing air with low Nr concentration and a unique isotopic composition. These results have important consequences for managing air pollution at the regional level, as they provide critical information for modeling Nr emission and deposition across regional as well as continental scales.

Elevated manganese (Mn) in drinking water has been reported worldwide. While, naturally occurring Mn in groundwater is generally the major source, anthropogenic contamination by Mn-containing fungicides such as mancozeb may also occur. The main objective of this study was to examine factors associated with Mn and ethylenethiourea (ETU), a degradation product of mancozeb, in drinking water samples from villages situated near banana plantations with aerial spraying of mancozeb. Drinking water samples (n = 126) were obtained from 124 homes of women participating in the Infants' Environmental Health Study (ISA, for its acronym in Spanish), living nearby large-scale banana plantations. Concentrations of Mn, iron (Fe), arsenic (As), lead (Pb), cadmium (Cd) and ethylenethiourea (ETU), a degradation product of mancozeb, were measured in water samples. Only six percent of samples had detectable ETU concentrations (limit of detection (LOD) = 0.15 μg/L), whereas 94% of the samples had detectable Mn (LOD = 0.05 μg/L). Mn concentrations were higher than 100 and 500 μg/L in 22% and 7% of the samples, respectively. Mn was highest in samples from private and banana farm wells. Distance from a banana plantation was inversely associated with Mn concentrations, with a 61.5% decrease (95% CI: −97.0, −26.0) in Mn concentrations for each km increase in distance. Mn concentrations in water transported with trucks from one village to another were almost 1000 times higher than Mn in water obtained from taps in houses supplied by the same well but not transported, indicating environmental Mn contamination. Elevated Mn in drinking water may be partly explained by aerial spraying of mancozeb; however, naturally occurring Mn in groundwater, and intensive agriculture may also contribute. Drinking water risk assessment for mancozeb should consider Mn as a health hazard. The findings of this study evidence the need for health-based World Health Organization (WHO) guidelines on Mn in drinking water.

Worldwide seagrass declines have been observed due to multiple stressors. One of them is the mixture of pesticides used in intensive agriculture and boat antifouling paints in coastal areas. Effects of mixture toxicity are complex and poorly understood. However, consideration of mixture toxicity is more realistic and ecologically relevant for environmental risk assessment (ERA). The first aim of this study was to determine short-term effects of realistic herbicide mixture exposure on physiological endpoints of Zostera noltei. The second aim was to assess the environmental risks of this mixture, by comparing the results to previously published data. Z. noltei was exposed to a mixture of four herbicides: atrazine, diuron, irgarol and S-metolachlor, simulating the composition of typical cocktail of contaminants in the Arcachon bay (Atlantic coast, France). Three stress biomarkers were measured: enzymatic activity of glutathione reductase, effective quantum yield (EQY) and photosynthetic pigment composition after 6, 24 and 96 h. Short term exposure to realistic herbicide mixtures affected EQY, with almost 100% inhibition for the two highest concentrations, and photosynthetic pigments. Effect on pigment composition was detected after 6 h with a no observed effect concentration (NOEC) of 1 μg/L total mixture concentration. The lowest EQY effect concentration at 10% (EC10) (2 μg/L) and pigment composition NOEC with an assessment factor of 10 were above the maximal field concentrations along the French Atlantic coast, suggesting that there are no potential short term adverse effects of this particular mixture on Z. noltei. However, chronic effects on photosynthesis may lead to reduced energy reserves, which could thus lead to effects at whole plant and population level. Understanding the consequences of chemical mixtures could help to improve ERA and enhance management strategies to prevent further declines of seagrass meadows worldwide.

We calculated farm, land, and soil N-budgets for countries in Europe and the EU27 as a whole using the agro-economic model CAPRI. For EU27, N-surplus is 55 kg N ha⁻¹ yr⁻¹ in a soil budget and 65 kg N₂O–N ha⁻¹ yr⁻¹ and 67 kg N ha⁻¹ yr⁻¹ in land and farm budgets, respectively. NUE is 31% for the farm budget, 60% for the land budget and 63% for the soil budget. NS values are mainly related to the excretion (farm budget) and application (soil and land budget) of manure per hectare of total agricultural land. On the other hand, NUE is best explained by the specialization of the agricultural system toward animal production (farm NUE) or the share of imported feedstuff (soil NUE). Total N input, intensive farming, and the specialization to animal production are found to be the main drivers for a high NS and low NUE.