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Are the effluents of wastewater treatment plants in high mountains of concern for aquatic biodiversity? To answer this question, we carried out an experimental study testing the short-term toxicity of some Pharmaceutical Active Compounds (PhACs) in the effluents of a plant in a mountain valley of the Italian Alps sampled during the high tourist season (i.e., the ski season) when PhACs contamination is higher. We used different tools, taking as a model the bacterium Aliivibrio fischeri: the “whole-mixture approach” (Microtox test), “component-based approach”, predictive models “Concentration Addition (CA)”, “Independent Action (IA)”, and Combination Index (CI)”. We investigated the nature of interactions potentially occurring among seven selected PhACs (clarithromycin, naproxen, acetaminophen (paracetamol), ibuprofen, diclofenac, carbamazepine, and amoxicillin). This study showed that anti-inflammatory ibuprofen and diclofenac have higher short-term toxicity (IC50

Recently, the use of Daphnia magna has been proposed in on-line and real-time biomonitoring programmes as an early warning system for evaluating the effluent quality of sewage treatment plants (STPs). These systems are based on recording behavioural changes in the test organism resulting from the stress caused by the effluents. Indeed, altered behavioural signals could be induced at sublethal concentrations that are significantly lower than the corresponding EC50. However, at present, it is unknown whether the sensitivity of D. magna can be representative of that of other aquatic organisms, particularly benthic macroinvertebrates. An experiment was designed to verify whether D. magna can be employed in biomonitoring programmes for STPs located in alpine areas as a surrogate for cold freshwater best-adapted species. The responses of survival and behaviour alteration to exposure to the effluent of the Tonale Pass plant (Trentino, Italian Alps, 46°N, 10°E; 1799 m a.s.l.) were compared in a laboratory population of D. magna and a wild population of the chironomid Diamesa cinerella. These larvae were collected from the Vermigliana stream 50 metres upstream of the effluent input. Both organisms were exposed for 24 and 48 hrs to the effluent as it is and to three dilutions (/10, /100, /1000). The mortality rate and behavioural responses (using video tracking systems) were recorded. No significant mortality or change in behaviour was observed in the two species when exposed to the undiluted effluent. Exposure to serial dilutions of the treated effluent did not affect the survival of either species but notably altered their behaviour at both exposure times (e.g., the time spent in activity in D. magna and the average speed of movement and the cumulative distance travelled in both), especially when exposed to the ten-times-diluted effluent. Overall, the findings of this study emphasize that even though D. magna and D. cinerella use different behavioural strategies to cope with adverse environmental conditions, their overall sensitivity to treated effluents is similar. Accordingly, the use of D. magna in biological early warning systems protocols seems to also be sufficiently protective for local, cold-adapted species of alpine freshwater ecosystems.

The metabolic effects of low oxygen content on alcohol-dehydrogenase (ADH) activity and hemoglobin (Hb) concentration were investigated in IV-instar larvae of Chironomus riparius (Diptera: Chironomidae) from an Italian stream. Two series of short-term (48 h) experiments were carried out: exposure to (1) progressive hypoxia (95 to 5% of oxygen saturation) and (2) anoxia (at 50% and decreased significantly only after 48 h of treatment (= 2 gAFDW-1 h-1. ADH activity showed two phases of growth, within the first 14 h and over 18 h of exposure. Overall, we inferred that i) Hb might function as short-term oxygen storage, enabling animals to delay the on-set of anaerobiosis; and ii) alcoholic fermentation co-occurs for a short time with aerobic respiration, becoming the prevalent metabolic pathway below 5% of oxygen saturation (-1). These considerations were supported also by results from anoxia exposure (2). In such condition, larvae were visibly stressed, becoming immobile after few minutes of incubation, and ADH reached higher values than in the hypoxia treatment (2.03±0.15 UADH mg prot-1). Overall, this study showed a shift from aerobic to anaerobic activity in C. riparius larvae exposed to poorly oxygenated water with an associated alteration of ADH activity and the Hb amount. Such metabolites might be valid candidate biomarkers for the environmental monitoring of running waters.

1.A collection of approximately 100 000 chironomids (Diptera; Chironomidae) inhabiting glacial areas of the Southern Alps that were collected over a period of approximately four decades from 1977 to 2014 were analysed to evaluate the impact of environmental traits on the distribution of chironomid species. Although the list of species has not substantially changed over time, some rare species captured in the 1970s have not been collected in recent years, while other species have only been collected recently. 2.The recovered correlation between altitude of the sampling sites and the date of collection since the first sampling event emphasises the need, in recent years, to sample at higher altitudes to collect species living near the glacier snout. This result confirms the impact of glacial retreat on chironomid communities. 3.Temporal trends in diversity were not emphasised throughout the collecting period. 4.A canonical correspondence analysis (CCA) showed that the influence of glaciers is the ecological trait that is the most robust predictor of the spatial distribution of species. This trait was highly correlated with the first CCA axis. Diamesa steinboecki, Diamesa latitarsis, Diamesa modesta, Diamesa goetghebueri and Diamesa laticauda are species that are known to be restricted to glacial habitats and were correlated with the first axis. The second CCA axis separated Western from Central-Eastern glaciers, with Diamesa cinerella prevailing in the former. 5.The threshold indicator taxa analysis, which detects changes in the distribution of taxa along an environmental gradient, confirmed the results of CCA in selecting Diamesa species with the strongest preference for glacial habitats.