The rapidity of ocean acidification intensifies selection pressure for resilient phenotypes, particularly during sensitive early life stages. The scope for selection is greater in species with greater within-species variation in responses to changing environments, thus enhancing the potential for adaptation. We investigated among-male variation in sperm swimming responses (percent motility and swimming speeds) of the serpulid polychaete Galeolaria caespitosa to near- (delta pH 0.3) and far-future ocean acidification (delta pH 0.5). Responses of sperm swimming to acidification varied significantly among males and were overall negative. Robust sperm swimming behavior under near-future ocean acidification in some males may ameliorate climate change impacts, if traits associated with robustness are heritable, and thereby enhance the potential for adaptation to far-future conditions. Reduced sperm swimming in the majority of male G. caespitosa may decrease their fertilization success in a high CO2 future ocean. Resultant changes in offspring production could affect recruitment success and population fitness downstream.

chapitre 45 | International audience | Agricultural systems occupy approximately 24 % of Earth’s terrestrial surface.They have been ensuring a vital ecosystem service, since food production kept pace with population growth in the course of the twentieth century. Most of the past balance has been ensured through agricultural intensification. There currently is, however, an obvious mismatch between human population sizes (and thus food demand) and food production among regions of the world. Further, alarming signs indicate that maintaining a balance between the world’s population growth and its food supply in the coming decades will become a major challenge, especially in the context of global, including climate, change. Agricultural systems involve inflows and outflows, which determine their performances. Outflows include primary, desirable ones (e.g., crop yields) and secondary, often undesirable outflows (e.g., nutrient and pesticide losses to the environment). Inflows include non-substitutable ones, with essential roles for crop growth and plant metabolism (e.g., water, seeds, nutrients), while others are substitutable (e.g., labor, mechanization, pesticides). These inflows contribute to the growth-defining, growth-limiting, and growth-reducing factors, which determine three levels of plant production: potential, attainable, and actual. Three entry points to enhance the performances of agricultural systems are considered, through increasing (1) potential yields, (2) attainable yields, and (3) actual yields. The latter entry point, which involves improving crop health, has several advantages. One of them is that its likely impact is at least equivalent to increasing potential yields or attainable yields. Another critical advantage of increasing actual yields, especially through the improvement of crop health, is that it allows addressing not only the quantity of harvests but also their quality, thus fulfilling the goals of achieving both global food security and food safety. We propose that this conclusion applies to all levels of agricultural intensification, in particular intensive agricultural systems, (1) which are potentially more exposed to crop loss risks, (2) whose performances are particularly vulnerable to global change, and (3) which will continue to play a central role in global food security and safety.

The stock of the European eel (Anguilla anguilla L.) continues to decline and has reached a new minimum in 2011. Poor health status of the spawners due to organic contaminants is one of the possible causes for this dramatic situation. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants, which are rapidly metabolized in vertebrates. EROD (ethoxyresorufin-O-deethylase) and GST (glutathione-S-transferase) are two enzymes involved in PAH detoxification in fish. In this study, PAH metabolites as well as EROD and GST activity in a large, comprising dataset of more than 260 migratory and pre-migratory eels from five large German river basin districts were used to describe PAH exposure and its metabolism as possible indicators for the habitat quality for eels. Eel from the river Elbe appear to be moderately contaminated with PAH. Highest mean values of PAH metabolites were analysed in fish from the river Rhine. However, the results suggest that contaminants such as PAH are metabolized in the fish and may have contributed to EROD activity in eels caught from the Elbe estuary to 600 km upstream. Since the eel’s onset of cessation of feeding is closely linked to maturation and migration, we propose bile pigments as new indicators contributing to identify the proportion of migratory eel, which is crucial information for eel management plans. We showed that PAH metabolites normalized to bile pigments as well as EROD could be used to describe the habitat quality and might be suitable parameters in search for suitable stocking habitats.

We used the Environment Health Risk Assessment framework to assess the health risks due to Pb and Cd in tilapia and water spinach caught/harvested along the Nhue River, in Kim Bang, Ha Nam in 2013. In total, 81 samples of water, tilapia and water spinach (27 of each) were taken from Nhue River and analysed for lead (Pb) and cadmium (Cd) pollution. 142 consumers were interviewed regarding the consumption levels of tilapia and water spinach. The analysis found that 100% samples of water spinach were contaminated with Pb and Cd; 100% and 96.3% of the tilapia samples were contaminated with Pb and Cd. The concentrations of Pb and Cd in water spinach were in the ranges of 29 – 385 µg/kg and 0.79 – 27 µg/kg. Their ranges in tilapia samples were 15 – 389 µg/kg and 0.12 – 8.8 µg/kg. The average consumptions of water spinach and tilapia were estimated at 108.9 g per meal and 132 g per meal, respectively. Local residents consumed 75 water spinach meals per year, therefore Pb and Cd intakes were 13.6 µg per week and 1.95 µg per month, respectively. For tilapia, the consumption frequency was 65 meals per year, Pb and Cd intakes were 9.7 µg per week and 1.88 µg per month, respectively. Most of the intake levels were lower than the recommended levels set by WHO. However, 14.08% of the surveyed residents had elevated Pb intakes from contaminated water spinach.

Defoliation is an indicator for forest health in response to several stressors including air pollutants, and one of the most important parameters monitored in the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests). The study aims to estimate crown defoliation in 2030, under three climate and one nitrogen deposition scenarios, based on evaluation of the most important factors (meteorological, nitrogen deposition and chemical soil parameters) affecting defoliation of twelve European tree species. The combination of favourable climate and nitrogen fertilization in the more adaptive species induces a generalized decrease of defoliation. On the other hand, severe climate change and drought are main causes of increase in defoliation in Quercus ilex and Fagus sylvatica, especially in Mediterranean area. Our results provide information on regional distribution of future defoliation, an important knowledge for identifying policies to counteract negative impacts of climate change and air pollution

Due to hydrophobic and persistent properties, polycyclic aromatic hydrocarbons (PAHs) have a high capacity to accumulate in sediment. Sediment quality criteria, for the assessment of habitat quality and risk for aquatic life, include understanding the fate and effects of PAHs. In the context of European regulation (REACH and Water Framework Directive), the first objective was to assess the influence of sediment composition on the toxicity of two model PAHs, benzo[a]pyrene and fluoranthene using 10-day zebrafish embryo-larval assay. This procedure was undertaken with an artificial sediment in order to limit natural sediment variability. A suitable sediment composition might be then validated for zebrafish and proposed in a new OECD guideline for chemicals testing. Second, a comparative study of toxicity responses from this exposure protocol was then performed using another OECD species, the Japanese medaka. The potential toxicity of both PAHs was assessed through lethal (e.g., survival, hatching success) and sublethal endpoints (e.g., abnormalities, PMR, and EROD) measured at different developmental stages, adapted to the embryonic development time of both species. Regarding effects observed for both species, a suitable artificial sediment composition for PAH toxicity testing was set at 92.5 % dry weight (dw) silica of 0.2-0.5-mm grain size, 5 % dw kaolin clay without organic matter for zebrafish, and 2.5 % dw blond peat in more only for Japanese medaka. PAH bioavailability and toxicity were highly dependent on the fraction of organic matter in sediment and of the K ow coefficients of the tested compounds. The biological responses observed were also dependent of the species under consideration. Japanese medaka embryos appeared more robust than zebrafish embryos for understanding the toxicity of PAHs following a sediment contact test, due to the longer exposure duration and lower sensitivity of sediment physical properties.

For decades, the explosive RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) has been used for military and industrial applications. Residues of RDX pollute soils in large areas globally and the persistence and high soil mobility of these residues can lead to leaching into groundwater. Dendroremediation, i.e. the long-term use of trees to clean up polluted soils, is gaining acceptance as a green and sustainable strategy. Although the coniferous tree species Norway spruce and Scots pine cover large areas of military land in Central Europe, the potential of any coniferous tree for dendroremediation of RDX is still unknown. In this study, uptake experiments with a 14C-labelled RDX solution (30 mg L−1) revealed that RDX was predominantly retained in the roots of 6-year-old coniferous trees. Only 23 % (pine) to 34 % (spruce) of RDX equivalents (RDXeq) taken up by the roots were translocated to aboveground tree compartments. This finding contrasts with the high aerial accumulation of RDXeq (up to 95 %) in the mass balances of all other plant species. Belowground retention of RDXeq is relatively stable in fine root fractions, since water leaching from tissue homogenates was less than 5 %. However, remobilisation from milled coarse roots and tree stubs reached up to 53 %. Leaching from homogenised aerial tree material was found to reach 64 % for needles, 58 % for stems and twigs and 40 % for spring sprouts. Leaching of RDX by precipitation increases the risk for undesired re-entry into the soil. However, it also opens the opportunity for microbial mineralisation in the litter layer or in the rhizosphere of coniferous forests and offers a chance for repeated uptake of RDX by the tree roots.