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Ecotoxicological assays on monospecific phytoplankton have limited application for detecting the effects of environmental pollutants on multiple species communities. With this study, we took an ecotoxicological, ecological, and biochemical approach to evaluate the effects of two contaminants of emerging concern (zinc oxide nanoparticles, ZnO NPs, and potassium dichromate, K2Cr2O7) at different concentrations (K2Cr2O7 5.6–18–50 mg/L, ZnO NPs 10–100–300 mg/L) on natural freshwater and brackish water phytoplankton communities. Cell density and absorbance values decreased in freshwater and brackish water phytoplankton communities after exposure to ZnO NPs (100 mg/L and 300 mg/L only for freshwater), whereas growth rate was increased in both freshwater and brackish water phytoplankton communities after exposure to ZnO NPs 10 mg/L. Differently, there was no clear relationship between concentration and inhibition growth after exposure to K2Cr2O7: the lowest cell density was recorded after exposure to 18 mg/L. Moreover, the evenness index value was lower compared to the other concentrations, indicating the growth of a few, albeit resistant species to higher K2Cr2O7 concentrations. Generally, Bacillariophyceae and Dinoficee were prevalent in phytoplankton cultures after exposure to ZnO NPs and K2Cr2O7. The Shannon-Wiener index was slightly higher in the negative than the positive controls, but diversity was low after all treatments in both ecotoxicological assays. The evenness index was always very close to zero, indicating the numerical predominance of one or very few species. Finally, the decrease in chlorophyll-a and pheophytin-a in both ecotoxicological assays indicated a change in photosynthetic activity. Our findings provide evidence for alterations in natural phytoplankton after exposure to emerging contaminants that can disrupt an entire ecosystem’s integrity.

Alpine lakes are extreme ecosystems located in remote areas and populated by few but well-adapted species. Because of their remote location, they are often considered pristine, unpolluted ecosystems. Since the 1980s, however, they have been affected by global anthropogenic impacts. Macrobenthic invertebrates play a pivotal role in these ecosystems and can be used as bioindicators also for monitoring the accumulation of trace elements. We characterized the macrobenthic invertebrates community of Balma Lake (Cottian Alps, Northwest Italy) and Dimon Lake (Carnic Alps, Northeast Italy) in summer and autumn and measured the levels of nine trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Se, Zn) in the most abundant taxa (Chironomidae and Oligochaeta in both lakes and Hirudinea in Dimon Lake) in both seasons. The highest levels of trace elements were recorded for Fe, Cu, and Zn according to their environmental availability and their function as essential elements. The total amount of trace elements was highest for the Chironomidae from both lakes compared to the other two taxa. As, Cd, Pb, and Zn were measured in sediment to calculate bioaccumulation factor (BAF) values. The amount of elements in sediment and macrobenthic invertebrates was higher for Dimon Lake, suggesting a greater flux via precipitation of contaminants from the lowland. The BAF values were decreased with increasing trace elements concentration in sediment, indicating mechanisms of elements excretion in biota where the environment is contaminated. This study is the first to report on the use of macrobenthic invertebrates to monitor trace elements in Alpine lakes.

This work reports a mortality outbreak, occurred in 2015 and affecting juveniles of European perch (Perca fluviatilis L.) farmed in Italy. Perch rhabdovirus (PRV) was de‐tected by viral isolation and biomolecular investigations. Phylogenetic analysis clus‐tered our isolate into genogroup B, which also includes PRV isolates from Perca fluviatilis identified in France (2004–2009); diagnostic investigations also revealed opportunistic bacteria (Aeromonas hydrophila) and parasites (Chilodonella piscicola). Since, occasionally, PRV has been reported in the natural environment, which is often a source of eggs and broodstock for farms, it could be possible that both similar France and Italian isolate were imported from a same place elsewhere and have a common origin. Improving biosecurity measures (batch control) and disinfection of egg strings with an iodine‐based solution helps prevent apparent vertical transmis‐sion of PRV.

Microplastics pose a major threat for aquatic ecosystems, but the contamination dynamics in organisms inhabiting freshwater ecosystems is still little studied. Largely used for biomonitoring, macrobenthic invertebrates provide a pivotal trophic resource for many fish and bird species. In this study, we investigated the microplastics contamination in a macrobenthic invertebrate community (2772 individuals belonging to 33 taxa identified) in a high-plain riverine ecosystem (Vipacco River, northeast Italy) and compared the amount of microplastics accumulated in functional feeding guilds/functional habit groups. Microplastics (cellulosic fibers associated with polyester) were found in 48.5% of the taxa, with the highest amount detected in the collector-gatherers, followed by predators. The collector-gatherers showed a significantly higher microplastic accumulation than the other functional feeding guilds, whereas there was no difference among the functional habit groups. The main source of microplastics pollution was most likely urban wastewater discharge points located along the river. Our study reports a novel approach about microplastic pollution assessment in lotic environments, as it focuses into the microplastic contamination dynamics in an entire macrobenthic invertebrate community perspective and underlines the need for further study.

The monitoring of microplastics pollution in freshwater environments trails behind its practice in marine ecosystems. We evaluated the use of the invasive zebra mussel (Dreissena polymorpha) as a potential bioindicator of microplastic litter in freshwater lakes. Samples were collected from three sites (Lovere, Costa Volpino, Castro) at the northern end of Lake Iseo (one of the major subalpine lakes in north Italy) and compared for water physicochemical parameters, biometrical features of zebra mussels, and microplastics items/specimens (color, shape, size, and chemical composition). We hypothesized that since a wastewater treatment plant (WWTP) on the Oglio River discharges into this area of the lake, the microplastics in D.polymorpha could be measured and compared in samples from the three sites at different distances from the WWTP. There was no difference in the physicochemical water parameters and biometric features between the samples from the three sites, whereas there was a significant difference in items/specimen between the sites in decreasing order (mean ± standard deviation): Costa Volpino (0.23 ± 0.43) &gt, Lovere (0.07 ± 0.25) &gt, Castro (0.03 ± 0.18). The chi-square test showed a significant difference in shape, color, and chemical composition frequency in the samples from the three sites. The chemical composition of the microplastics was polyethylene terephthalate (45%), nylon (20%), polypropylene (20%), polyamide resin (10%), and polyvinyl chloride (5%). Our data show that the amount of microplastics the zebra mussel accumulated was greater the closer the sampling site to the WWTP. Our findings suggest that the zebra mussel may provide a useful tool to monitor microplastics pollution in lakes.

We investigated modern-littoral and subfossil sediment-core diatoms in the shallow (max depth 6.4 m) high-mountain Lake Balma in the Orsiera Rocciavre Nature Park (Italian Western Alps). Our study provided evidence that might be related to the response of diatom assemblages to fish introduction, in particular the decreasing of the nutrient-enrichment sensitive low-profile life-form/ecological guild and the increase in species known to react positively to the augmented nutrient availability due to fish excretions (e.g., Fragilaria nanana, Pseudostaurosira brevistriata, Staurosirella neopinnata). We are, however, aware that some of these effects could as well have been caused by pastures and cattle watering, and by increased temperatures due to global warming, and we acknowledge the typical complex-interaction pattern among different stressors. High-mountain lakes are ‘‘early warning systems’’ for the whole alpine system and can contribute valuable information also on the interactions between environmental global changes and anthropogenic impacts. Benthic diatoms, in particular, can provide useful indications on the deleterious effects of non-native fish introduction, cattle grazing, and global warming, and thus support an adaptive and sustainable management of high-mountain lakes for the sake of nature conservation.

The present study provides energy density (ED) data and models for four macrobenthic invertebrate genera inhabiting freshwater lotic environments (Baetis, Hydropsyche, Rhyacophila, and Onychogomphus). Samples were collected in the hydrological freshwater network of the Region Friuli Venezia Giulia within different watercourse types (creeks, streams, rivers channels, and ditches), and energy density was directly measured using an adiabatic bomb calorimeter. Measured ED expressed in Joule g(-1) wet weight was strongly and positively correlated with percentage of dry weight (DW%) for all genera investigated (r(2) > 0.9504), allowing to obtain genus-specific predictive models based on the relationship between ED and DW%. Models were validated and showed good predictive power, as 90th percentile of observed percentage errors ranged between 4.23% and 5.18% while medians ranged between 1.32% and 2.83%. ANCOVA disclosed significant differences between the models, as those for Rhyacophila and Onychogomphus differed significantly from the others. The empirical models were used to build a dataset of estimated energy density, to assess the relationship between energy density and ecological status of the monitored riverine systems, assessed in compliance with European and Italian law by the application of four different ecological indices (ICMi, RQE_IBMR, STAR_ICMi, and LIMeco). Information regarding ED levels for freshwater macrobenthic invertebrates is still neglected in biomonitoring programs, but it could be useful to interpret some ecological situations in the context of ecological status assessment, especially in relation to the trophic condition of the investigated riverine systems.

With this study we investigated the accumulation of potentially toxic elements (As, Cd, Cr, Cu, Hg, Pb, Zn), six indicators (28, 52, 101, 138, 153, 180) of non-dioxin-like polychlorinated biphenyls (Σ6 NDL-PCBs), polycyclic aromatic hydrocarbons (PAHs), and microplastics in S. quadrata (edible part) collected from two sampling sites (1 and 2) from the Arno River Basin (Central Italy). A risk assessment of the implications for human health was also performed. Levels of potentially toxic elements in gastropods from site 2 were slightly higher and the Σ6 NDL-PCB concentration was significantly higher (7.32ngg−1vs. 3.07ngg−1) compared to site 1 due to higher anthropogenic pressures. The concentration of chrysene, benzo[b]fluoranthene, and benzo(a)pyrene was below the limit of quantification (0.5μgkg−1). Benzo[a]anthracene was detected in gastropods from both sites (0.5 ± 0.02μgkg−1 and 0.7 ± 0.02μgkg−1 from site 1 and 2, respectively). The microplastics frequency (mainly polyethylene terephthalate) differed significantly between the sites (site 1, 0.8 ± 1.30; site 2, 1 ± 0.37 items/specimen). All contaminant levels were compliant with international regulatory limits and guidelines. Incremental lifetime cancer risk (ILCR) values for As, Cd, Cr, and Pb were far below the safety values of 1 × 10–4. Similarly, the ILCR values from the Monte Carlo simulation model were all within the safety region of 1 × 10–4 and 1 × 10–6. Findings from the health risk assessment indicated no adverse effects for human health from any of the contaminants analysed here, except for microplastics for which no limits or legislation are currently in force.

Fish can be highly vulnerable to environmental pressures because they are exposed to oxidative stressors in the aquatic environment. Such stressors can affect the levels of antioxidant biomarkers against reactive oxygen species (ROS). With this study we investigated the oxidative stress ecology in Danube barbel (Barbus balcanicus) from the Barbucina creek (northeast Italy), a watercourse in the Collio winegrowing district. To do this, superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) activity was measured in gills, liver, and muscle, while metallothioneins (MT) and trace and rare earth elements (REEs) levels were determined in muscle. The effect of environmental factors (physicochemical parameters of water, trace elements and REEs) on oxidative stress biomarkers was thus assessed. High concentrations were determined for cerium (Ce), scandium (Sc), neodymium (Nd), lanthanum (La), yttrium (Y), and praseodymium (Pr) among the REEs. Among the trace elements, arsenic (As), copper (Cu), and mercury (Hg) levels were higher compared to published data, suggesting their role as stressors. The multiple linear regression (MLR) model showed a statistically significant association (R2 = 0.858; F = 10.07; p = 0.015) between As, Cu, Hg, and Pr and SOD activity in the gills, indicating a functional relationship between them. Differently, CAT activity was significantly higher in the liver, probably in response to long-term Cu contamination of the watercourse. This was confirmed by the MLR model that showed a significant association (R2 = 0.638; F = 8.152; p = 0.02) between the concentration of MT and of Cu. Our data show a biochemical defensive response by Danube barbel to the disturbances in the aquatic ecosystem of the Barbucina creek. These insights advance our understanding of the role and the effects of environmental factors as trace elements and REEs on oxidative stress in fish.

Dibothriocephalus latus (Linnaeus, 1758) (Cestoda: Diphyllobothriidea, syn. Diphyllobothrium latum), is a fish-borne zoonotic parasite responsible for diphyllobothriasis in humans. Although D. latus has long been studied, many aspects of its epidemiology and distribution remain unknown. The aim of this study was to investigate the prevalence, mean intensity of infestation, and mean abundance of plerocercoid larvae of D. latus in European perch (Perca fluviatilis) and its spatial distribution in three commercial fishing areas in Lake Iseo (Northern Italy). A total of 598 specimens of P. fluviatilis were caught in 2019. The total prevalence of D. latus was 6.5%. However, there were significant differences between areas (10.2% North, 7.3% Center, 1.5% South) (Chi-square test, p = 0.0018). The mean intensity of infestation ranged from 1 larva in southern area to 1.2 larvae in both the central and northern (Pisogne) areas. In addition, the mean abundance ranged from 0.02 in the southern area to 0.26 in the northern area (Pisogne). The total number of larvae (anterior dorsal&mdash, AD = 21, anterior ventral&mdash, AV = 1, posterior dorsal&mdash, PD = 15, posterior ventral&mdash, PV = 5) differed significantly between the four anatomical quadrants (Kruskal&ndash, Wallis test, p = 0.0001). The prevalence of D. latus plerocercoid larvae in European perch from Lake Iseo has long been investigated, but without an appropriate sampling design. With the present study, a broader analysis in spatial distribution has been added to the existing literature, revealing new information about D. latus distribution and occurrence in Lake Iseo, with new data that will be useful for health authorities and future studies.

Sturgeon aquaculture production has increased worldwide, particularly in Italy, yet there is little information about diseases that affect sturgeons. With this study we describe the results of screening for bacterial infections during monitoring campaigns carried out from 2014 to 2017. A total of 402 sturgeons from six sturgeon farms with one or more reared sturgeon species among five species and two hybrids were analysed. Bacteriological exam was positive in 93 individuals (23%) and negative in the remaining 309 (77%). Generally, no external or internal macroscopic lesions were present, though some specimens showed skin lesions, liver anaemia or splenomegaly, which are non‐pathognomonic signs of bacterial infection. The majority of the isolated bacteria were opportunistic. This knowledge base is important to help create a bacterial profile of sturgeons reared in Italy.

Introduction of exotic species is one of the major human impacts for decline in autochthonous biodiversity. In freshwater lentic environments, alien fish introduction heavily shapes macrobenthic invertebrate structure, with special regard for Chironomidae (Diptera) community. These effects could be more evident in alpine lakes whose environments are considered as remote and undisturbed, but extremely susceptible and vulnerable to both natural and anthropogenic impacts. In this context, modern and subfossil chironomid assemblages were studied in a high-altitude lake (Balma Lake, Piedmont, Italy) which was not previously investigated and subject to brook trout introduction for recreational fishing at the end of the twentieth century (after 1970). Seasonal samplings (summer, autumn) were performed in five littoral and three deep sites, while a core sample was extracted from the deepest point of the lake. The analysis highlighted significant differences in subfossil chironomid communities before and after fish introduction and between subfossil and modern communities, with notable decrease in recent diversities. Dissimilarities were mainly related to Corynocera oliveri, Zavrelimyia, Micropsectra, Metriocnemus, and Heterotrissocladius marcidus type. Therefore, this study highlights the importance and effects of anthropic environmental events, such as fish introduction, in climate reconstructions and their interpretation, especially regarding the last 100/200-year period, when human environmental issues have become more significant.

The genus Eustrongylides includes nematodes that infect fish species and fish-eating birds inhabiting freshwater ecosystems. Nematodes belonging to the genus Eustrongylides are potentially pathogenic for humans, infection occurs after the consumption of raw or undercooked fish. In the two-year period 2019&ndash, 2020, a total of 292 fish belonging to eight species were examined for the occurrence of Eustrongylides spp. from Lake San Michele, a small subalpine lake in northwest Italy. The prevalence of infestation was 18.3% in Lepomis gibbosus, 16.7% in Micropterus salmoides, and 10% in Perca fluviatilis. The other five fish species (Ameiurus melas, Ictalurus punctatus, Squalius cephalus, Carassius carassius, and Scardinius erythrophthalmus) were all negative for parasite presence. There were no significant differences in prevalence between the three fish species (Fisher&rsquo, s exact test, p = 0.744). The mean intensity of infestation ranged from 1 (M. salmoides and P. fluviatilis) to 1.15 (L. gibbosus), and the mean abundance ranged from 0.1 (P. fluviatilis) to 0.28 (L. gibbosus). There were significant differences in the infestation site between the four muscle quadrants (anterior ventral, anterior dorsal, posterior ventral, and posterior dorsal) and the visceral cavity (Kruskal&ndash, Wallis test, p = 0.0008). The study findings advance our knowledge about the distribution and host range of this parasite in Italy.

High-mountain lakes are pristine ecosystems characterized by extreme environmental conditions. The atmospheric transport of pollutants from lowlands may add further stress to organisms inhabiting these environments. We investigated the environmental stress pressure on brook trout (Salvelinus fontinalis) from a high-mountain lake in the Cottian Alps (Piedmont, northwest Italy). To do this, males and females of brook trout were sampled from Balma Lake in summer (August) and autumn (October) 2017 in order to assess the influence of trace elements accumulation and environmental parameters (physicochemical parameters and nutrient characteristics of water) on oxidative stress biomarkers. Bioaccumulation of Al, As, Cd, Cr, Cu, Fe, Hg, Pb, Ni, Se, and Zn and metallothionein levels were measured in muscle tissue of males and females. Liver, gills, kidney, and spleen tissue samples were analyzed for superoxide dismutase, catalase, total glutathione peroxidase, selenium-dependent glutathione peroxidase, glutathione reductase, and glutathione S-transferase activity. Analysis of environmental parameters showed changes in biomarker levels with seasonal variations. Water temperature was significantly higher in summer than autumn (Wilcoxon test; p = .0078), while pH was significantly higher in autumn than in summer (Wilcoxon test; p = .0078). Sex-related differences in oxidative stress biomarkers in tissues were unremarkable, whereas seasonal variability of oxidative stress biomarkers was observed, with major differences occurred for liver in summer and for gills, kidney, spleen and muscle in autumn. Positive correlations between environmental parameters and biomarkers were noted. Major fluctuations in water temperature, pH, Cu, Pb and Hg produced changes in biomarker levels; however, increased food intake during the ice-free season was probably the main factor that influenced changes in oxidative stress biomarker levels in brook trout in this extreme ecosystem.

Though mountain lakes are generally much less influenced by human activities than other habitats, anthropogenic threats can still alter their natural condition. A major source of global environmental pollution in mountain ecosystems is trace element contamination. For this study we investigated for the first time the accumulation of As, Cd, Pb, and Zn in sediment, Diptera Chironomidae (prey), and bullhead Cottus gobio (predator) in a typical high-mountain lake (Dimon Lake) in the Carnic Alps. Significant differences in trace element levels were observed between sediment, Diptera Chironomidae, and C. gobio liver and muscle samples (Kruskal-Wallis test; p < 0.03 for all elements). As and Pb levels were highest in sediment, Cd and Zn levels were highest in Diptera Chironomidae, and the lowest values for all elements were measured in C. gobio muscle and liver. Bioaccumulation factor values were much higher in Diptera Chironomidae than fish muscle and liver, with the highest values recorded for Cd (5.16) and Zn (4.37). Trophic transfer factor values were very low for all elements in fish muscle and liver, suggesting a biodilution effect along the food chain. Further studies are needed to expand on these first findings that provide useful insights to inform environmental monitoring and policy in remote high-mountain lakes

The aim of this study was to describe liver alterations observed in a bullhead (Cottus gobio) population from a high-mountain lake (Dimon Lake, 1857 m a.s.l.) located in Carnic Alps (Northeast Italy). Two fish sampling campaigns (summer and autumn) were performed in 2017 to explore the possible causes of this phenomenon. In addition, to investigate the typical liver features of C. gobio, control specimens were captured from Degano Creek in the same seasons. Total length, weight, and liver weight were recorded in fish from both sampling sites. In addition, Fulton&rsquo, s condition factor (K) and hepatosomatic index (HSI) were calculated. Stomach contents were also analyzed. Liver from each specimen was sampled, and histological examination was carried out. Liver steatosis (L) (nuclear displacement and cytoplasm vacuolization) were histologically evaluated by assigning a semiquantitative severity score. A significant difference in L was found between Dimon Lake and Degano Creek in both summer (Mann&ndash, Whitney test, p = 0.0001) and autumn (Mann&ndash, p &lt, 0.0001). Regarding HSI, a significant difference was also recorded between Dimon Lake and Degano Creek in summer (Mann&ndash, 0.0001) and also in autumn (Mann&ndash, 0.0001), but no seasonal change in K values was recorded between the two sites in both summer (Mann&ndash, p = 0.8589) and autumn (Mann&ndash, p = 0.6415). A significant positive correlation between HSI and L was found (&rho, S 0.573). The causes of this abnormality might be related to adaptation by the fish to the high-altitude environment, accumulating lipids in the liver to tackle the adverse season, which lasts for 6 months of the year. Nonetheless, our study does not preclude steatosis induced by a nearly exclusive chironomids diet in bullhead from Dimon Lake.

The parrotfish Sparisoma cretense, a marine species native to the eastern and southern coastal areas of the Mediterranean, has extended its distribution northward. Here, we provide an update on its distribution based on currently published data and two new records from the coastline of Sardinia, Italy (central-western Mediterranean). The survey methods were scuba diving and spearfishing: one specimen of S. cretense was caught along the Argentiera coastline (northwest Mediterranean) and the others were photographed in the Gulf of Orosei, Osalla Bay (central-eastern Mediterranean). A literature update, together with new records, documents the distribution of this species in the northernmost areas of the Mediterranean. Probably a result of global warming, the ongoing northward expansion of S. cretense highlights the need for sampling campaigns to obtain timely updates on population and distribution of this thermophilic species.

The hypothesis that liver lipid accumulation in fish is an adaptive strategy to survive the winter in the high-altitude environment was assessed in this study. During summer 2019, specimens of Cottus gobio were sampled in 15 watercourses of Friuli Venezia-Giulia Region (Italy) to verify if hepatic steatosis is or not normally present in the species. To do this, hepatic vacuolization was assessed by histology using a semiquantitative score. Furthermore, C. gobio were also captured during the ice-free season at Dimon Lake (1872 m a.s.l.) and But Stream (520 m a.s.l.) to compare the trend in lipid accumulation: water temperature, hepatosomatic index (HSI), gonadosomatic index (GSI), Fulton’s condition factor (K), and lipid area percentage (lipid %) were measured monthly. Findings revealed that liver steatosis is rather common in C. gobio. However, the trend in lipid accumulation of this species differed between Dimon Lake and But Stream. Based on the HSI and the GSI, the reproductive cycles differed in fish from the two environments (April–May in But Stream; May–June in Dimon Lake). While K values remained unchanged in the But Stream specimens, significant changes were recorded for Dimon specimens. The increase in lipid % from July to August in the Dimon Lake specimens coincided with greater food availability. With the rapid drop in lake water temperature in October, the lipid % decreased due to slower metabolic rate and lipid utilization from liver stores. There was a slight decrease in lipid % in the But Stream specimens, indicating that lipids were not being accumulated. Introduced years ago, the Dimon Lake bullhead population has since adapted to the winter conditions at high elevation.

Twelve biochemical parameters were measured in serum blood samples from rainbow trout (Oncorhynchus mykiss) maintained under controlled conditions. Forty-five samples were taken every 3 months (T1–T4) over the course of one year to define baseline values. The effect of fish total weight (TW) was also evaluated. Principal component analysis showed a clear separation between T4 and T1, and T2 and T3, indicating an increase in certain biochemical parameters with weight. Linear regression analysis showed how TW significantly explained 11–67% of the variability observed for nine parameters out of 12. Pearson’s correlation matrix showed a significant positive correlation (p < 0.05) between TW and albumin, alkaline phosphatase, alanine-aminotransferase, creatinine, gamma-glutamyl transferase, magnesium, phosphorus and total protein. Furthermore, significant correlations (p < 0.05) between the majority of the biochemical parameters were found, indicating that growth can influence several parameters at the same time. The present study provides several useful baseline values for assessing the health of O. mykiss, indicating that fish weight is an important factor for interpreting the blood biochemical profile.

Rare earth elements (REEs) are emergent contaminants in aquatic ecosystems in parallel with their growing use in science, technology, and industry. In this study we measured the concentration of 16 REEs in freshwater marcobenthic invertebrates from 6 watercourses in northeast Italy to determine their potential use as ecological tracers of REEs in aquatic ecosystems. The total REE concentration at the sampling sites followed this order: site 6 (7.05 mg Kg−1) > site 3 (5.76 mg Kg−1) > site 4 (3.58 mg Kg−1) > site 1 (3.0 mg Kg−1) > site 5 (2.36 mg Kg−1) > site 2 (1.95 mg Kg−1). There were no significant differences in REE concentrations across the six samplings sites (Kruskal Wallis test, p = 0.1773), but two (site 3 and 6) had higher amount of REEs and were classified with the ecological status “Moderate” sensu Water Framework Directive since affected by anthropogenic activities. Light REE were always greater than heavy REE concentrations at all six sites. A positive correlation was observed between certain REEs (La, Ce, Gd) and the density of genera Caenis and Baetis (Ehemeroptera, collector-gatherers) (ρS range 0.795–0.812), suggesting that non-predatory macrobenthic invertebrates accumulate more REEs than predatory organisms and that the intake of sediment is the most effective route of assimilation.

The present study is an attempt to deepen the knowledge about energy patterns in a detritus-based ecosystem located within a temporary wetland, where changes of water level can affect productivity, turnover of organic matter and the flow-through energy. Energy density was directly measured using an adiabatic bomb calorimeter in samples collected in autumn, spring and summer. Dipterans belonging to the genus Chironomus were the most common and representative invertebrates within the study area. Starting from these measures, a predictive model based on the relationship between energy density and percentage of dry weight was developed, validated and applied to build a multi-annual dataset. This model was used to investigate seasonal energy density trends on longer time-scale, in relation to physical and chemical features, weather conditions and decomposition dynamics. The used approach allowed to build a 3-year dataset and to identify clear seasonal trends; moreover, the application of the model highlighted patterns in relation to precipitation regime, decomposition dynamics and the effects due to variations of these features in the investigated temporary detritus-based system over a multi-annual scale.

Insect protein meals are considered as a promising alternative feedstuff in aquafeeds, but until now the effects induced by its dietary inclusion on histological features, gut mucin composition and oxidative stress in fish are still not assessed. In the present study, we describe these effects after inclusion of a partially defatted Hermetia illucens (HI) larvae meal in Oncorhynchus mykiss diets. Three isoproteic, isolipidic and isoenergetics diets were formulated containing HI larvae meal in partial substitution of fish meal: 0% (HI0, control diet), 25% (HI25) and 50% (HI50), corresponding to dietary inclusion levels of 0, 20% and 40% of HI. Fish were fed for 78 days with the experimental diets and at the end of the growing trial, histological and histochemical evaluations were performed on spleen, liver and gut samples of control and treatment groups. Oxidative stress biomarkers, such as superoxide dismutase, catalase, glutathione peroxidases, ethoxyresorufin O-deethylase, glutathione S-transferase, glutathione reductase, total glutathione and malondialdehyde were investigated in liver and kidney of experimental groups. Histopathological examination of liver, spleen and gut revealed no adverse effects following increasing levels of insect meal inclusions. Hermetia illucens consumption stimulated higher production of neutral than acidic mucins. Altered values of several antioxidant biomarkers indicated an unbalance of oxidative homeostasis in liver and mainly in kidney, linked to the feeding conditions. While lowering of glutathione peroxidase activity may reflect slight adverse effect of HI meals in both tissues, strengthening in levels of ethoxyresorufin O-deethylase, glutathione S-transferase and total glutathione may indicate the shielding of HI meals-mediated oxidative process. Although the administration of both inclusion levels of insect meal did not negatively affect the histological features in fish, the changes of oxidative stress biomarkers advise for an HI dietary inclusion lower than 20%.

2nd Freshwater Invasives - Networking for Strategy II (FINS-II) Conference -- JUL 11-14, 2016 -- Zagreb, CROATIA Skora, Michal Edward/0000-0002-9121-1318; Groom, Quentin/0000-0002-0596-5376; Lukas, Juliane/0000-0003-3336-847X; Skora, Michal/0000-0002-9121-1318; Piria, Marina/0000-0001-6324-9282; Smith, Emily/0000-0003-2767-9933; Simonovic, Predrag/0000-0002-4819-4962; Pastorino, Paolo/0000-0002-0585-1168; Koutsikos, Nicholas/0000-0003-0680-4504; Vilizzi, Lorenzo/0000-0001-8103-885X; Dobrzycka-Krahel, Aldona/0000-0002-4252-895X; Tarkan, Ali Serhan/0000-0001-8628-0514 WOS: 000412582000002 Invasive alien species (IAS) are a significant and growing problem worldwide. In Europe, some aspects of IAS have been addressed through existing legal instruments, but these are far from sufficient to tackle the problem comprehensively. The FINS II Conference considered the relevance of Top 20 IAS issues (Top 10 threats and opportunities) for Europe determined at the 1st Freshwater Invasiveness-Networking for Strategy (FINS I) conference held in Ireland in 2013. Using a similar format of sequential group voting, threats from FINS I (lack of funding, of awareness and education; poor communication) and several new threats (lack of lead agencies, of standardized management and of common approach; insufficient monitoring and management on private property) were identified by 80 academics, applied scientists, policy makers and stakeholders from 14 EU and three non-EU countries (including 10 invited speakers) during four workshop break-out sessions (legislation remit in both EU/non-EU countries; best management and biosecurity practice for control; data management and early warning; pathways of introductions and citizen science). Identified opportunities include improved cooperation and communication, education and leadership to enhance public awareness and stakeholder participation, systems establishment for early detection, rapid response, monitoring and management of IAS using standardised methods of data collection, storage and usage. The sets of threats and opportunities identified underline the importance of international cooperation on IAS issues in communication, education and funding as priorities, as well as in standardization of legislation, control methods and best practise of research. Univ Zagreb, European Inland Fisheries & Aquaculture Advisory Commiss University of Zagreb, Faculty of Agriculture; European Inland Fisheries and Aquaculture Commission (EIFAAC); Croatian Biological Society; Ministry of Science; Education and Sport of Republic of Croatia; Croatian Association of Sports Fishing Societies; Croatian Academy of Sciences and Arts; Nature Conservation Committee [NEC04932]; Natural Environment Research CouncilNERC Natural Environment Research Council [NEC04932]; UK Department of Environment, Food and Rural AffairsDepartment for Environment, Food & Rural Affairs (DEFRA); Irish EPA project "Prevention, control and eradication of invasive alien species" [2015-NC-MS-4]; Topfishing; Zagreb ZOO; Zagreb; Karlovac towns We wish to thank the University of Zagreb, Faculty of Agriculture, the European Inland Fisheries and Aquaculture Commission (EIFAAC), the Croatian Biological Society, the Ministry of Science, the Education and Sport of Republic of Croatia, the Croatian Association of Sports Fishing Societies, the Croatian Academy of Sciences and Arts, Topfishing, Zagreb ZOO, Zagreb and Karlovac towns for sponsoring the FINS II conference. We also thank the large number of people who assisted but are not co-authors on the manuscript including M. Pofuk, T. Stuhne, R. Jasarevic, K. Culag, I. Cuze, M. Cvitanic and S. Hudina for their selfless assistance during the conference. H.E. Roy received support from the Joint Nature Conservation Committee and the Natural Environment Research Council (via National Capability funding to the Centre for Ecology & Hydrology, project NEC04932), and G.H. Copp was supported by the UK Department of Environment, Food and Rural Affairs. COST Action TD1209 ALIEN Challenge is acknowledged. F. Lucy, J. Caffrey, J. Dick, E. Davis and N. Coughlan were supported by the Irish EPA project "Prevention, control and eradication of invasive alien species" (2015-NC-MS-4).