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Organism biomass, a continuous quantity, may be useful for general community and diversity assessment. Body length and biomass of benthic macroinvertebrates from two aquatic environments with different impact levels are determined in this study, classifying organisms using functional and taxonomic characteristics. Lyophilized benthic macroinvertebrate biomass was quantified to test for significant differences between an impacted and reference (less environmental impact) site. Results show that macroinvertebrate assemblages from the less impacted stream had higher average biomass than the assemblage from the perturbed site, and significant differences in biomass of Plecoptera, Trichoptera, predators, filterers and gills breathers were found between sites. The biomass signature was calculated for each analyzed scenario, weighting the presence of all specimens sampled considering the total biomass in a single regression curve equation. The cubic polynomial model had the best fit to the data. More background from theory to practice should be considered in biomonitoring research; hence we propose the application of macroinvertebrate biomass as an additional metric that will help evaluate the ecological status of streams, thus contributing to the knowledge of community-based biomonitoring of benthic macroinvertebrates.

In Chile, salt (NaCl) use per salmon fish farm ranges between 20-30 t yr(-1) and is used to prevent and control fungal infections. An increase in salinity in freshwater can have adverse effects on freshwater biodiversity and ecosystem functions and services. We studied the effects of fish-farm effluents on benthic macroinvertebrate communities in a northern Patagonian stream (Chile). Benthic samples were collected at 3 sites near a land-based salmon aquaculture facility (one located 100 m upstream from the fish-farm outlet for effluent, 2 sites located 200 and 400 m downstream from the effluent source). We found changes in benthic macroinvertebrate communities downstream from the effluent, with higher abundances of tolerant taxa and lower abundances of sensitive taxa, which was related to nutrient and salt concentration in the water. We also studied the effects of salinity on macroinvertebrate drift in a mesocosm experiment conducted in recirculating channels, measuring the drift of 2 salt-sensitive macroinvertebrates (Andesiops peruvianus and Smicridea annulicornis), collected from an unpolluted northern Patagonian stream, after exposure to a range of salinity concentration pulses similar to those from fish farms. Our results demonstrate that (1) fish-farm effluent can alter stream macroinvertebrate community composition and dynamics, and (2) such effects are at least partly driven by high salt concentrations in effluent waters. We thank the vice rectory for research and postgraduate studies at the Catholic University of Temuco and project MECESUP UCT 0804. The study was funded by the Fondecyt project 'Tracing organic pollution from land-based aquaculture systems in terms of fluorescence spectroscopy and assessment of ecotoxicological biomarkers in aquatic organisms in Southern Chile' (Ref. 1130132). L.B. was supported by the Spanish Ministry for Science, Innovation and Universities funds (Ref. RTI2018095023-B-I00) and Basque Government funds (Ref. IT95116) to the UPV/EHU Stream Ecology Group. Editorial

Microbes play a critical role in plant litter decomposition and influence the fate of carbon in rivers and riparian zones. When decomposing low-nutrient plant litter, microbes acquire nitrogen (N) and phosphorus (P) from the environment (i.e., nutrient immobilization), and this process is potentially sensitive to nutrient loading and changing climate. Nonetheless, environmental controls on immobilization are poorly understood because rates are also influenced by plant litter chemistry, which is coupled to the same environmental factors. Here we used a standardized, low-nutrient organic matter substrate (cotton strips) to quantify nutrient immobilization at 100 paired stream and riparian sites representing 11 biomes worldwide. Immobilization rates varied by three orders of magnitude, were greater in rivers than riparian zones, and were strongly correlated to decomposition rates. In rivers, P immobilization rates were controlled by surface water phosphate concentrations, but N immobilization rates were not related to inorganic N. The N:P of immobilized nutrients was tightly constrained to a molar ratio of 10:1 despite wide variation in surface water N:P. Immobilization rates were temperature-dependent in riparian zones but not related to temperature in rivers. However, in rivers nutrient supply ultimately controlled whether microbes could achieve the maximum expected decomposition rate at a given temperature. Collectively, we demonstrated that exogenous nutrient supply and immobilization are critical control points for decomposition of organic matter. Key Points • Nitrogen (N) and phosphorus (P) immobilization was measured on organic matter (cotton) in 100 rivers and riparian zones representing 11 biomes • Elevated temperature in riparian zones and phosphate in rivers increased immobilization, and consequently accelerated decomposition • N and P immobilization was strongly linked by microbial stoichiometry despite widely varied surface-water nutrient ratios Plain Language Summary Bacteria and fungi contribute to the breakdown of leaf litter in rivers and floodplains. To break down leaf litter, these microbes need the nutrients nitrogen and phosphorus (P), and microbes can get nutrients either from the leaf litter itself or from the environment. Most leaf litter has low nutrient content and microbes must rely on the environment to supply nutrients. We studied microbial nutrient uptake from the environment during litter breakdown to determine whether it varies predictably across the globe and how it is influenced by changing climate and nutrient pollution. In 100 rivers and floodplains in 11 of Earth's major biomes we placed small strips of cotton as stand-ins for leaf litter. Nutrient uptake was consistently greater on cotton strips that were submerged in the river compared to cotton on the floodplain. For microbes in the river, nutrient uptake was faster in instances where there was more P in the water. For microbes in the floodplain, nutrient uptake was faster where temperatures were warmer. Faster nutrient uptake by microbes was linked with faster cotton breakdown in rivers and floodplains. Our study shows that climate change and nutrient pollution can alter the activity of microbes in rivers and floodplains.

Human activities have led to an increase in land use change, with effects on the structure and functioning of ecosystems. The impact of contrasting land uses along river basins on the concentration of colored dissolved organic matter (CDOM) reaching the coastal zone, and its relationship with the carbonate system of the adjacent coastal ocean, is poorly known. To understand the relationship between land use change, CDOM and its influence on the carbonate system, two watersheds with contrasting land uses in southern Chile were studied. The samples were collected at eight stations between river and adjacent coastal areas, during three sampling campaigns in the austral summer and spring. Chemical and biological samples were analyzed in the laboratory according to standard protocols. Landsat 8 satellite images of the study area were used for identification and supervised classification using remote sensing tools. The Yaldad River basin showed 82% of native forest and the Colu River basin around 38% of grassland (agriculture). Low total alkalinity (AT) and Dissolved Inorganic Carbon (DIC), but high CDOM proportions were typically observed in freshwater. A higher CDOM and humic-like compounds concentration was observed along the river-coastal ocean continuum in the Yaldad basin, characterized by a predominance of native forests. In contrast, nutrient concentrations, AT and DIC, were higher in the Colu area. Low CaCO3 saturation state (ΩAr

During the last 40 years time lapse photography has become a strong tool for in situ observations of marine and freshwater wildlife. We compared the validity of two low cost camera systems to analyze the filtration activity of Diplodon chilensis (Gray, 1828), the most common freshwater bivalve in southern Chile. One camera system (Nikon D300) was connected with an external flash, whereas the other system (GoPro Hero 3+) contained a permanent video light source. Size change of the total area of the exhalant siphon (ESA) of Diplodon individuals was used to track activity changes over time. Each ESA is expressed as the percentage of the maximum siphon opening of the corresponding specimen. The siphon of D. chilensis was completely closed for 3.4% ± 5.2% (mean ± SD) of the recording time and it shows a nearly completely opened siphon for 42.7% ± 22.9% of the recording time. The mean siphon opening was 68.3% ± 26.5% of its potential opening area. Although a red filter (permeable to wavelengths above 600 nm ) was placed in front of the video light source, the mobile fauna, especially Aegla abtao (Schmitt, 1942) and unidentified small fishes were highly attracted by the permanent light, whereas this effect was not visible when a flash light in intervals of 2 min was used. We conclude that both low cost cameras are very suitable for in situ time lapse observation of freshwater clams.

The distribution, composition, and transport of both dissolved and particulate organic carbon (DOC and POC) were studied across a terrestrial - marine transition system in the Chilean North-Patagonia (41°S). At the land-fjord boundary we reported: (i) high concentrations of both silicic acid (up to 100 μM) and integrated chlorophyll a (62 mg m−2), (ii) dominance of nanophytoplankton (63%), humic-, terrigenous-derived, and protein-like DOC (19 and 36%, respectively), and (iii) a shallow photic zone (12 m depth). In contrast, the estuarine-ocean boundary was characterized by (i) high concentrations of nitrate and phosphate (20 and 2 μM respectively) and low chlorophyll a concentration (11 mg m−2), (ii) dominance of microphytoplankton (59%) and tyrosine-like C3 autochthonous DOC (34%), and (iii) a deep photic zone (29 m depth). Allochthonous DOC input at the fjord head and the ocean accounted for 60% and 10% of total DOC, respectively. The input of humic-like substances was enhanced by intense forestry and agriculture activity around the Puelo River watershed, contributing from 50% to 14% of total DOC along the fjord - ocean transect. In contrast, autochthonous tyrosine-like substances increased from 25% to 41% of total DOC, highlighting the role of bacterial metabolism in regulating DOM composition. The high correlation (R2 = 0.7) between the UVC-humic:UVA-humic ratio and salinity suggest that processes associated to freshwater input impinged on the DOC chemical characteristics and origins. Overall, our observations support the view that climate warming (freshwater input) and anthropogenic practices (aquaculture) boost the mobilization of terrestrial carbon pools and their intrusion into coastal ocean areas, a process that should be given more attention in climate prediction models.

In this study, the occurrence and diffusive air-water exchange of POPs in Panguipulli Lake (39°42'S-72°13'W), an oligotrophic lake located in northern Patagonia (Chile), were determined. Air and water samples were collected between March and August 2017 (autumn-winter) and analyzed for concentrations of OCPs (α-HCH, β-HCH, γ-HCH and HCB) and PCBs (PCB-28,-52,-101,-118,-153,-158,-180) using gas chromatography coupled with an electron capture detector. The direction of air-water exchange direction was evaluated using a fugacity approach (ƒw ƒa-1), and net diffusive exchange fluxes (FAW, ng m-2 d-1) were also estimated. Total ∑4OCP levels in air ranged from 0.31 to 37 pg m-3, with a maximum for β-HCH, while Σ7PCB levels ranged from 3.05 to 43 pg m-3. The most abundant congener was PCB-153, accounting for 60% of the total PCBs in air. Surface water ∑4OCPs measured in this study ranged from 1.01 to 3.9 pg L-1, with γ-HCH predominating, while surface water Σ7PCB levels ranged from 0.32 to 24 pg L-1, with PCB-101, PCB-118, and PCB-153 presenting the highest levels. Diffusive air-water exchanges of HCB, α-HCH, γ-HCH and PCBs in the form of volatilization from the lake to air predominated; in contrast, for β-HCH net deposition dominated during the sampling period. Estimates suggested faster microbial degradation in the dissolved phase compared to atmospheric degradation for all analyzed POPs. Overall, these results could indicate that the oligotrophic lakes of northern Patagonia act as a secondary source of atmospheric POPs, mainly PCBs and some OCPs. This study is a first attempt to understand the occurrence of POPs in air and water, as well as their dynamics in oligotrophic lakes in the southern hemisphere., This study was funded by ANID/FONDECYT/Iniciación 11150548, ANID/FONDECYT/Regular 1161504, ANID/FONDECYT/Regular 1210946, ANID/PCI REDI170292, ANID PIA INACH ACT192057, INACH REGULAR RT_12_17 (C. Galbán-Malagón) and ANID/FONDECYT/Postdoctorado Nº3180159 (F. Tucca). Additionally, the authors acknowledge the support of the ANID/FONDAP/CRHIAM/15130015 and ANID/FONDECYT/1161673 projects (R. Barra). The authors are grateful for the logistical help of the Universidad Austral de Chile in the collection of water and air samples at Panguipulli Lake.

En las últimas décadas, la nanotecnología ha emergido como un área de investigación que está encontrando aplicaciones en múltiples campos. El mercado actual incluye nanomateriales que proporcionan grandes ventajas sobre los materiales en su forma convencional, una de éstas, su mayor área de contacto, lo que los hace ideales como sustancias catalíticas, mejorando este tipo de procesos con la consecuente reducción de insumos. Dentro de los nanomateriales comúnmente utilizados, las nanopartículas de oro se han aplicado principalmente en biomedicina, salud y belleza, sector automotriz y electrónica. Sin embargo, el uso cada vez más generalizado de nanopartículas no va aparejado con estudios sobre el impacto ambiental que conlleva la disposición final de sus residuos, especialmente en medios acuáticos, destino habitual de muchas sustancias utilizadas en procesos industriales, los cuales han sido poco estudiados. La presente investigación aborda el efecto que tienen las nanopartículas de oro con recubrimiento de quitosano sobre Daphnia pulex, microorganismos generadores primarios en la cadena trófica. Como resultado fundamental de este trabajo se estableció una dosis letal media (EC50) de 0.5721 mg/L de Au en este tipo de microorganismos, este estudio confirma así la importancia de llevar a cabo más investigación sobre la toxicidad de nanopartículas funcionalizadas, especialmente de oro, en organismos acuáticos microscópicos que son la base de muchas cadenas tróficas en ríos y lagos.

El cáncer de mama es un problema de salud pública en el mundo, esta enfermedad es la principal causa de muerte por cáncer en las mujeres; por ello, es fundamental sumar esfuerzos para el desarrollo de estrategias que permitan mitigar su impacto social, económico y a la salud. Las moléculas activas derivadas de las plantas (fitofármacos) son una fuente prometedora de soluciones para esta problemática y su mejoramiento con la aplicación de sistemas de liberación de fármacos de base nanotecnológica es sin duda, una estrategia que debe ser evaluada para ofrecer alternativas para el tratamiento de los pacientes oncológicos. La consideración correcta de los factores que impactan en el éxito de estas estrategias es primordial, por ello, en este capítulo se exponen los fundamentos teóricos para la obtención de fitofármacos nanotransportados para el tratamiento del cáncer de mama, así como una breve introducción a esta neoplasia; el concepto de fitofármacos, sus métodos de obtención y las características de calidad que deben cumplir; así mismo, se describen los sistemas nanométricos para el transporte de fármacos contra el cáncer y las características fisicoquímicas y de calidad que estos deben cumplir para su éxito. Finalmente, se exponen algunos avances que este grupo de investigación ha logrado en el desarrollo de fitofármacos nanotransportados para el tratamiento del cáncer de mama.

Actualmente las enfermedades cardiovasculares representan la principal causa de morbimortalidad en el mundo; la aplicación de la nanotecnología es una gran promesa para su prevención y tratamiento. Actualmente se están desarrollando nanodispositivos para la liberación dirigida y controlada de medicamentos en sitios específicos en el organismo, por ejemplo, en células, tejidos, vasos sanguíneos y el corazón, así como para su diagnóstico, detección temprana de enfermedades cardiovasculares y tratamiento individualizado de pacientes. Otra aplicación de los nanodispositivos es la liberación de fármacos para corregir el mal acoplamiento de proteínas defectuosas. Con potentes superefectos, las nanopartículas deben ser capaces de provocar efectos terapéuticos a bajas dosis en periodos prolongados. La fabricación de nanodispositivos y nanoacarreadores deberá llevarse a cabo con un enfoque integral que tome en cuenta las propiedades generales, con la finalidad de evaluar la biocompatibilidad y, en consecuencia, evitar efectos adversos y tóxicos. La investigación intensificada en este campo ayudará a disminuir significativamente la morbimortalidad provocada por las enfermedades cardiovasculares. El presente trabajo incluye una sinopsis que describe algunos de los avances más recientes, relevantes y comunes de la nanomedicina en las ECV.

The global aquaculture industry has grown exponentially in recent years using to control of infections and diseases, a variety of veterinary drugs (VMP) are used, including antibiotics, antifungals and antiparasitics, which have different routes of emission, environmental persistence and side effects to aquatic organisms, becoming one of the main concerns in its use of veterinary drugs (VMP) and its potential toxicological impact on the environment, in this context, Chile is considered one of the main salmon producers. Ecological risk assessment of active principles used infreshwater fish farms worldwide and in Chile were investigated. We recollect a physical - chemical properties of active principles used by fish farms and we could estimate the relative hazard a priori. Later active principles grouped as antibiotics (n = 6), antiparasitics (n = 5), anesthetics (n = 3), and disinfectants (n = 7) were assessed using a mass balance model based on fugacity was developed for each active principle under treatments via immersion and food administration in fish, while a volumetric model for disinfectants and sodium chloride was used for estimating the predicted environmental concentration (PEC), under a real smolt farming scenario in fish farms. Ecotoxicological data were collected from open literature to predict the no-effect concentration (PNEC). The ecological risk assessment was characterized using a risk quotient (RQ = PEC/PNEC) based in two assessment tiers. Results revealed that 12 active ingredients showed a high risk (RQ ≥ 1), thus indicating that adverse effects could occur and further investigation with measured concentrations in the field are required to reduce exposure in surface waters.

Salmon aquaculture is an important economic activity globally where local freshwater supplies permit land-based salmon aquaculture facilities to cultivate early life stage salmon. Nitrogen, phosphorus and organic matter in aquaculture effluents contribute to the eutrophication of adjacent and downstream rivers and lakes. This study quantifies the enrichment of nutrients in land-based salmon aquaculture facility effluents compared to receiving waters. We measured nutrient concentrations and dissolved organic matter (DOM) quantity and quality via fluorescence spectroscopy in streams and effluent waters associated with 27 facilities in Chile. We found that facilities added on average 0.9 (s.d. = 2.0) mg-C L-1, 542 (s.d. = 637) μg-total N L-1, and 104 (s.d. = 104) μg-total P L-1 to effluents compared to stream waters. DOM in stream water was enriched in humic-like fluorescence, while aquaculture effluents were enriched in protein-like DOM fluorophores. Principal component and correlation analysis revealed that tryptophan-like fluorescence was a good predictor of total N and P in effluents, but the strength of significant linear relationships varied among individual facilities (r2: 0.2 to 0.9). Agreement between laboratory fluorescence and a portable fluorometer indicates the utility of in-situ sensors for monitoring of both tryptophan-like fluorescence and covarying nutrients in effluents. Thus, continuous in-situ sensors are likely to improve industry management and allow more robust estimates of aquaculture-derived nutrients delivered to receiving waters.

Fish from both aquaculture and wild capture are exposed to veterinary and medicinal antibiotics (ABs). This study explored the occurrence and probable source of 46 antibiotic residues in muscle of farmed salmon and wild trout from Chile. Results showed that at least one AB was detected in all studied samples. Diverse patterns were observed between farmed and wild specimens, with higher ABs concentrations in wild fish. Considering antimicrobial resistance, detected ABs corresponded to the categories B (Restrict), C (Caution) and D (Prudence) established by Antimicrobial Advice Ad Hoc Expert Group (European Medicines Agency). Multivariate statistic was used to verify differences between farmed and wild populations, looking for the probable source of ABs as well. Principal components analysis (PCA) revealed that ciprofloxacin, moxifloxacin, enrofloxacin, amoxicillin, penicillin G, oxolinic acid, sulfamethoxazole, trimethoprim and clarithromycin were associated with wild samples, collected during the cold season. Conversely, norfloxacin, sulfaquinoxaline, sulfadimethoxine, nitrofurantoin, nalidixic acid, penicillin V, doxycycline, flumequine, oxacillin, pipemidic acid and sulfamethizole were associated with wild samples collected during the warm season. All farmed salmon samples were associated with ofloxacin, tetracycline, cephalexin, erythromycin, azithromycin, roxithromycin, sulfabenzamide, sulfamethazine, sulfapyridine, sulfisomidin, and sulfaguanidine. In addition, linear discriminant analysis showed that the AB profile in wild fish differ from farmed ones. Most samples showed ABs levels below the EU regulatory limit for edible fish, except for sulfaquinoxaline in one sample. Additionally, nitrofurantoin (banned in EU) was detected in one aquaculture sample. The differences observed between farmed and wild fish raise questions on the probable source of ABs, either aquaculture or urban anthropic activities. Further research is necessary for linking the ABs profile in wild fish with the anthropic source. However, to our knowledge, this is the first report showing differences in the ABs profile between wild and aquaculture salmonids, which could have both environmental and health consequences.

Streamside native forests are known for their key role in water provision, commonly referred to as buffers that control the input or output of nutrients from terrestrial to aquatic ecosystems (i.e., nitrogen or carbon cycle). In order to assess the functional role of indigenous forests along streamside channels, we measured 10 parameters associated with DOM (Dissolved Organic Matter) at 42 points in 12 small catchments (15&ndash, 200 ha) dominated by native forests (reference, WNF), forest plantations (WFP) and agricultural lands (WAL) in which the land cover portion was calculated in the entire watershed and along 30 and 60-m wide buffer strips. We found that watersheds WFP and WAL were statistically different than WNF, according to DIC concentrations (Dissolved Inorganic Carbon) and the intensity of the maximum fluorescence of DOM components. Using linear models, we related streamside native forest coverage in buffer strips with DOM parameters. The increase of streamside native forest coverage in 60 m wide buffer strips (0&ndash, 100%) was related to lower DIC concentrations (0.89 to 0.28 mg C L&minus, 1). In watersheds WFP and WAL, the humic and fulvic-like components (0.42 to 1.42 R.U./mg C L&minus, 1) that predominated were related to an increase in streamside native forest coverage in the form of a 60 m wide buffer strip (0&ndash, 75%). This is evidence that streamside native forests influence outputs of detritus and lowered in-stream processing with concomitant downstream transport, and functional integrity and water quality. We propose that DOM quantity and quality may be a potential tool for the identification of priority areas near streams for conservation and ecological restoration in terms of recovery of water quality as an important ecosystem service. The results of this study are useful to inform policy and regulations about the width of streamside native forests as well as their characteristics and restrictions.

Protected areas (PAs) are critically important means to preserve species and maintain natural ecosystems. However, the potential impacts of chemical pollution on PAs are seldom mentioned in the scientific literature. Research on the extent of the occurrence of chemical pollution inside PAs and in-depth assessments of how chemical contaminants may adversely affect the maintenance of species abundance, species survival, and ecosystem functions are scarce to nonexistent. We investigated 1) the occurrence of chemical contaminants inside 119 PAs in Latin America from publically available databases, and 2) reviewed case studies of chemical contaminants and pollution in 4 Latin American PAs. Cases of chemical pollution and contamination inside Latin American PAs mostly originated from sources such as mining, oil, and gas extraction. To date, the focus of the research on chemical pollution research inside Latin American PAs has been primarily on the detection of contamination, typically limited to trace metals. Where management actions have occurred, they have been reactive rather than proactive. Protected areas established in wetlands are the most affected by chemical pollution. Based on the information from the pollution and/or contamination occurrence and the case studies analyzed, Latin American PAs are not well safeguarded from chemical pollution, resulting in both challenges and opportunities to conserve biodiversity and ecosystems. Integr Environ Assess Manag 2017;13:360-370. © 2016 SETAC.

Element determination in plankton is important for the assessment of metal contamination of aquatic environments. Until recently, it has been difficult to determine elemental content in rotifers or ciliates derived from natural plankton samples because of the difficulty in handling and separation of these fragile organisms. The aim of this study was to evaluate methods for separation of rotifers and large ciliates from natural plankton samples (μg range dry weight) and subsequent analysis of their elemental content using total-reflection X-ray fluorescence spectrometry (TXRF). Plankton samples were collected from different aquatic environments (three lakes, one river) in Chile, Argentina and Hungary. From one to eighty specimens of five rotifer species (Brachionus calyciflorus, Brachionus falcatus, Asplanchna sieboldii, Asplanchna sp., Philodina sp.) and four to twelve specimens of one large ciliate (Stentor amethystinus) were prepared according to the dry method originally developed for microcrustaceans, and analysed by TRXF following in situ microdigestion. Our results demonstrated that it possible to process these small and fragile organisms (individual dry mass: 0.17–9.39 μg ind- 1) via careful washing and preparation procedures. We found species-dependent differences of the element mass fractions for some of the elements studied (Cr, Mn, Fe, Ni, Cu, Zn, As, Pb), especially for Cu, Fe and Mn. One large rotifer species (A. sieboldii) also showed a negative correlation between individual dry weight and the element content for Pb, Ni and Cr. We conclude that our application of the in situ microdigestion-TRXF method is suitable even for rotifers and ciliates, greatly expanding the possibilities for use of plankton in biomonitoring of metal contamination in aquatic environments.

Blooms of cyanobacteria have negative effects on aquatic organisms and even on human health, since many species can synthesize dangerous toxins. Studies on cyanobacteria and their potential toxicity have been very scarce in Chile and have been limited to lakes of the central zone. Recently, North-Patagonian lakes, although characterized by their low nutrient concentration and low productivity, revealed also the presence of blooms of cyanobacteria, mainly constituted by Microcystis and Dolichospermum species (former Anabaena sp.). To identify potential toxicological risk associated to these blooms, six North Patagonian lakes (Lakes Caburgua, Villarrica, Calafquen, Panguipulli, Ranco, and Puyehue) were sampled during the summer period and screened for the presence of cyanobacteria and different toxins. Our results revealed for the first time the presence of microcystins in all studied lakes, whereas other toxins such as cylindrospermopsin, saxitoxin, and anatoxin were negative for all sites. By applying a genomic approach, Cylindrospermopsis raciborskii was found in one lake (Lake Ranco) constituting the first report of this cyanobacterium in a Chilean lake. This study highlights the effectiveness of molecular methods as a first approach to describe cyanobacteria and their potential cyanotoxins in Chilean North-Patagonian lakes.

Polycyclic aromatic hydrocarbons (PAHs) are semivolatile organic compounds of environmental concern. This study aims to investigate the influence of local sources of anthropogenic PAHs and their air–water exchange fluxes in an oligotrophic North–Patagonian lake in Chile. The monitoring was carried out in Panguipulli Lake during a six-month period during the autumn and winter seasons (March to August 2017) using a high–volume air sampler and a pump system for water samples. We detected and quantified fifteen PAHs in the gas phase (mean ∑PAHs = 11.6 ng m) and dissolved water phase (mean ∑PAHs = 961.8 pg L). Methylphenanthrenes and pyrene dominated the concentrations of PAHs in the studied phases. To determine sources of PAHs we used the PAH ratios of Light Molecular Weight/Heavy Molecular Weight (∑LMW/∑HMW) and Phenanthrene/Anthracene (Phe/Ant). The PAH ratio results revealed a pyrogenic source. We estimated the air–water diffusive exchange fluxes and fugacity ratios for the studied compounds. In general, air–water diffusive exchanges of PAHs showed a net volatilization for the less hydrophobic (log K < 4) and lighter PAHs (MW ≤ 170 g mol), and a net deposition trend for the more hydrophobic (log K 4–7) and higher molecular weight PAHs (MW ≥ 178 g mol). We found a significant correlation between log water/air fugacity ratios and log K of PAHs. Therefore, it is suggested that this oligotrophic lake acts as a sink by accumulating hydrophobic and mid-high molecular weight PAHs derived mainly from pyrogenic sources. This study is the first attempt to understand the sources and behavior of PAHs in oligotrophic lakes in the Southern Chile where information is scarce regarding the occurrence of PAHs., This study was funded by ANID FONDECYT 11150548, 1161504, ANID PCI REDI170292, ANID PIA Anillo INACH ACT192057, INACH REGULAR RT_12_17 (C. Galbán-Malagón) and ANID FONDECYT N° 3180159 (F. Tucca). Authors also thank the support of ANID FONDAP CRHIAM 15130015 (R. Barra and F. Tucca), ANID FONDECYT 1161673 (K. Pozo), “Universidad Andrés Bello” is thanked for funding a PhD scholarship awarded to Miss Thais Luarte. The “Universidad Austral de Chile” was highly acknowledged by their continuous logistic support on the lake. Kevin Ryan PhD(c) is thanked for language editing of the final version of the present manuscript.

The suitability of Mazzaella laminarioides and Sarcothalia crispata as heavy metal biomonitors of Cd, Cu, Hg, Pb, and Zn was assessed by comparing bioaccumulation of these elements in different life stages and frond sizes in samples from three locations, San Vicente Bay (industrial area), Coliumo, and Quidico (the latter as a reference station), where different degrees of heavy metal pollution are recorded. Bioaccumulation and bioconcentration factors of Cd, Cu, Hg, Pb, and Zn were evaluated. The two macroalgae species showed similar patterns, with higher values of Cu, Hg, Pb, and Zn in polluted areas. M. laminarioides bioaccumulated higher concentrations of all metals assessed than S. crispata, independent of life stage and frond size. The results also showed significantly higher Cu, Hg, Pb, and Zn concentrations (p

Aquacultures are of great economic importance worldwide but pollute pristine headwater streams, lakes, and estuaries. However, there are no in-depth studies of the consequences of aquacultures on dissolved organic matter (DOM) composition and structure. We performed a detailed molecular level characterization of aquaculture DOM quality and its bacterial degradation using four salmon aquacultures in Chile. Fluorescence measurements, ultrahigh-resolution mass spectrometry, and nuclear magnetic resonance spectroscopy of the DOM revealed specific and extensive molecular alterations caused by aquacultures. Aquacultures released large quantities of readily bioavailable metabolites (primarily carbohydrates and peptides/proteins, and lipids), causing the organic matter downstream of all the investigated aquacultures to deviate strongly from the highly processed, polydisperse and molecularly heterogeneous DOM found in pristine rivers. However, the upstream individual catchment DOM signatures remained distinguishable at the downstream sites. The benthic algal biovolume decreased and the bacterial biovolume and production increased downstream of the aquacultures, shifting stream ecosystems to a more heterotrophic state and thus impairing the ecosystem health. The bacterial DOM degradation rates explain the attenuation of aquaculture DOM within the subsequent stream reaches. This knowledge may aid the development of improved waste processing facilities and may help to define emission thresholds to protect sensitive stream ecosystems.

International audience; Cyanobacterial blooms can be harmful to environmental and human health due to the production of toxic secondary metabolites, known as cyanotoxins. Microcystins (MCs), one of the most widespread class of cyanotoxins in freshwater, have been found to be positively correlated with cyanobacterial biomass as well as with nitrogen and phosphorus concentrations in temperate lakes. However, in tropical water bodies,cyanobacterial density and cyanotoxin correlation to environmental factors is not fully understood. In the present study, we examined the effects of total nitrogen and total phosphorus (TP) concentrations among other environmental parameters on cyanobacterial community structure and MC concentrations in the Dau Tieng reservoir, a tropical, eutrophic water body in Southern Vietnam. Cyanobacterial biomass and MC content were monitored monthly from March 2012 to February 2013, when MCs were present in the Dau Tieng Reservoir. The highest concentrations of intracellular MCs were found in September and February when cyanobacteria biomass reached maximum values, with 2.50 and 2.13 mg MC.L–1, respectively. Principle component analysis and redundancy analysis showed that MC concentration was positively correlated with the biomass of the cyanobacterial order Chroococcales, whereas TP was the primary abiotic factor influencing cyanobacterial biomass and MC concentrations in the Dau Tieng Reservoir. In addition, Bayesian model average analysis was used to construct a prediction model of MCs using cyanobacterial biomass and environmental variables revealing a suite of useful predictive factors for MCs in the Dau Tieng Reservoir, includingwater temperature, TP and the biomass of Chroococcales.

Protected areas (PAs) are critically important means to preserve species and maintain natural ecosystems. However, the potential impacts of chemical pollution on PAs are seldom mentioned in the scientific literature. Research on the extent of the occurrence of chemical pollution inside PAs and in-depth assessments of how chemical contaminants may adversely affect the maintenance of species abundance, species survival, and ecosystem functions are scarce to nonexistent. We investigated 1) the occurrence of chemical contaminants inside 119 PAs in Latin America from publically available databases, and 2) reviewed case studies of chemical contaminants and pollution in 4 Latin American PAs. Cases of chemical pollution and contamination inside Latin American PAs mostly originated from sources such as mining, oil, and gas extraction. To date, the focus of the research on chemical pollution research inside Latin American PAs has been primarily on the detection of contamination, typically limited to trace metals. Where management actions have occurred, they have been reactive rather than proactive. Protected areas established in wetlands are the most affected by chemical pollution. Based on the information from the pollution and/or contamination occurrence and the case studies analyzed, Latin American PAs are not well safeguarded from chemical pollution, resulting in both challenges and opportunities to conserve biodiversity and ecosystems. Integr Environ Assess Manag 2017;13:360-370. © 2016 SETAC.

International audience; Seven strains of cyanobacteria from Tri An Reservoir, a drinking water reservoir for millions of people in Southern Vietnam, were isolated, cultivated, identified and described. They originated from the species Microcystis aeruginosa, M. botrys, M. wesenbergii, Anabaena circinalis,A. smithii, Aphanizomenon aphanizomenoides and Cylindrospermopsis raciborskii. Microcystin (MC) content in the cultures and two scum samples from Tri An Reservoir were determined by high performance liquid chromatography. Four variants of MC, MC-LR, MC-RR, MC-LA, MC-LY and one un-determined variant were detected in the scum samples but none were found in the cultures. The two variants MC-LA and MC-LY were recorded for the first time for Vietnam. Total MC concentrations in the two scum samples were 0.45 and 0.64 mg g-1 dried weight, respectively. The genus Microcystis in Tri An Reservoir was assumed to be a MC producer as the other possible MC producing species A. circinalis was usually detected in lower quantities.

* Corresponding author. E-mail: reda_grigutyte@yahoo.com Leaf litter is one of the allochthonous sources of dissolved organic carbon (DOC) in freshwater ecosystems. Th roughout the degradation of leaves, a lot of chemical compounds are set free into water, which may promote oxidative stress via generation of reactive oxygen species and / or by disturbance of the intracellular oxidative balance in aquatic organisms. We investigated concentrationand time-dependent relationships for the activities of oxidative stress enzymes in macrophytic algae cells of Nitellopsis obtusa, induced by beech Fagus sylvatica leaf extracts, respectively, 0.11–55.0 mg L–1 DOC (aft er 24 h) and 1.1 mg L–1 DOC aft er (15 min – 24 h). Th e oxidative stress enzymes included catalase (CAT – E. C. 1.11.1.6), glutathione reductase (GR – E. C. 1.6.4.2), cytosolic and microsomal glutathione S-transferase (GST – E. C. 2.5.1.18). A signifi cant increase in sGST and mGST activities aft er a 24-h exposure to 1.1–11.0 mg L–1 and to 5.5 mg L–1 DOC of beech leaf extracts was detected. sGST activity signifi cantly increased in the whole period of exposure, while mGST activity decreased below control levels when exposed for 1–4 h. Glutathione reductase activity increased signifi cantly at all DOC concentrations of beech leaf extracts aft er 24 h of exposure. Th e highest elevation of GR activity was observed in extracts containing 5.5 mg L–1 DOC and the lowest activity increment at 0.11 mg L–1 DOC. A statistically signifi cant increase in GR activity started aft er 1 h (at 1.1 mg L–1 DOC) and was evident until the end of the 24-h exposure. Th e activity of catalase increased signifi cantly only at the lowest (1.1 mg L–1) DOC concentration aft er 24 h of exposure. Beech leaf extracts induced a statistically signifi cant time-dependent elevation of CAT activity during the whole period of exposure. In general, an increase of antioxidative enzyme activities in charophyte Nitellopsis obtusa indicated that the defence mechanisms against oxidative stress were induced when cells had been exposed to beech leaf extracts.

Leaf litter is one of the major input sources of organic carbon and nutrients in freshwater ecosystems. Throughout the degradation and leaching of leaf litter in freshwater bodies, “new born” substances are continuously generated and may aggregate to form humic substances (HS). Although the effect of HS on the stress physiology of aquatic macrophytes has been case of several investigations, the effect of these “new born” compounds (leaf litter breakdown products) on the stress physiology of aquatic plants has not been studied yet. Our results show that leaf litter degradation extracts (LLDEs) from oak, beech, and mixed oak and beech leaves have deleterious effects on the physiology of the aquatic bryophyte Vesicularia dubyana, decreasing photosynthetic activity and enhancing oxidative stress response. These findings suggest that leaf litter degradation extracts may be an important environmental factor influencing community structure within freshwater ecosystems.

Influence of housefly maggot meal (magmeal) diets on the activities of catalase (CAT), glutathione S-transferase (GST) and glycogen concentration in liver of Tilapia Oreochromis niloticus fingerling was evaluated. Triplicate groups of fifteen fish (initial average weight 2.0+/-0.1 g) were fed eight weeks with seven test diets (in average 36% crude protein, dry matter) formulated by replacing fish meal with magmeal. Percentage body weight gain (591-724.46%), food conversion ratio (1.05-1.22) and standard growth rate (3.45-3.76) in all feeding groups were not significantly different (P

Chile is the second largest producer of salmonids worldwide. The first step in the production of salmonids takes place in land-based aquacultures. However, the effects of the discharge from these aquacultures on stream dissolved organic matter (DOM) content, molecular composition and degradability are unknown. The aim of this study was thus to investigate the inputs of anthropogenic DOM from land-based aquaculture to the predominantly pristine river systems of North Patagonia. We hypothesized, that i) DOM exported from land-based aquaculture mainly consists of protein-like fluorescence (tyrosine and tryptophan) released from fish feces and food remains, and that ii) this DOM is highly degradable and therefore rapidly turned-over within the receiving streams. In the North Patagonian region we conducted a screening of ten land-based aquacultures and an intensive sampling campaign for one aquaculture. This was combined with longitudinal transects and a degradation experiment in order to couple the composition of DOM exported from land-based aquacultures to its degradability in streams. We measured dissolved organic carbon (DOC) concentration by high-temperature catalytic oxidation and DOM composition by fluorescence spectroscopy and parallel factor analysis. In the effluent of the ten screened aquacultures and in the repeated sampling of one aquaculture, we consistently found an increase of DOC concentrations and a dominance of protein-like fluorescence. The protein-like fluorescence rapidly disappeared downstream of the aquacultures, and in the degradation experiment. 21 % of the DOC export from the repeatedly sampled aquaculture resulted from food addition and 76% from fish production. We conclude that large amounts of degradable DOM are exported from land-based aquacultures. This probably has strong effects on the ecological structure and function of North Patagonian streams, and similarly affected streams worldwide.

We report the evaluation of changes in water quality, increasing pollution level, of a section of Suquía River basin (Córdoba, Argentina) by using Myriophyllum quitense as bioindicator in addition to the measurement of chemical parameters, combined with chemometrics (ANOVA, Cluster and Discriminant Analysis). Myriophyllum quitense was collected upstream from Córdoba city at an unpolluted site of Suquía River basin. After collection plants were transplanted to different sites with different pollution levels. Subsequent to transplantation plants were weekly collected from the original site as well as from transplantation stations. Water quality was evaluated throughout the transplantation experiment, while the use of this macrophyte as bioindicator was verified through the activation of its antioxidant defenses and biotransformation system. Myriophyllum quitense reacts to the pollution stress increasing the activity of glutathione-S-transferases (CDNB and Fluorodifen), glutathione reductase (GR) and peroxidase (POD). Elevated enzyme activities agreed to different pollution levels, especially inorganic nitrogen loads combined with elevated lead and aluminum concentrations, all of them originated by anthropogenic activities, thus presenting Myriophyllum quitense as a good biomonitor for assessment of water quality in this polluted aquatic ecosystem.

Dissolved organic matter (DOM) in freshwater ecosystems has its origin in a multitude of terrestrial and aquatic sources which determine amount, composition and thereby its functions. Spectroscopic methods are used to characterize chromophoric DOM. Among these methods, absorbance and fluorescence spectroscopy can provide indications of sources, behavior, and biogeochemical cycling of DOM. Since DOM is defined as the part of the organic matter pool which passes filters from 0.22 to 0.7 μm, sample filtration is required before spectroscopic measurements can be done. However, the use of different filter types might be influencing the results of DOM composition measurements. In order to assess the effect of different filters, we used three filter types with nominal pore sizes of 0.7, 0.45 or 0.22 μm, measured difference spectra, calculated spectroscopic indexes ( S 275–295 , S 350–400 , S r , SUVA 254 , E2:E3, fluorescence index, β : α , humification index) and fluorescence components (parallel factor analysis, PARAFAC), obtained via spectroscopic measurements from water with different characteristics (e.g. river water, wetland, sewage effluent). Our results show that the filter types had significant but small effects on the chromophoric DOM composition and that meta-analyses of DOM composition based on studies with different pore size can be done, when keeping potential minor filtration effects in mind. This is important for further meta-analysis which might inter-compare data sets on spectroscopic characterization of DOM.

International audience; Freshwater mussels such as the invasive Dreissena polymorpha and the indigenous Unio tumidus nourish by high filtration rates and may accumulate cyanobacteria and their toxins during cyanobacterial blooms. Physiological adaptations to cyanotoxins enable organisms to endure cyanobacteria lblooms but may differ between species. Biotransformation and excretion capacities for cyanobacteria and anthropogenic pollutants have been demonstrated for Dreissena polymorpha but less for unionid species. This study compares the activities of biotransformation (glutathioneS-transferase, GST) and antioxidant enzymes (superoxide dismutase, SOD and catalase, CAT) in Dreissena polymorpha to Unio tumidus in response to cyanotoxin exposure (10 mg L 1 and 50 mg L 1 microcystin-LR, respectively, total microcystin from a cyanobacterial crude extract) for 24h and 7 d exposure duration. Enzyme activities in Dreissena polymorpha were measured in the whole mussel tissue, digestive gland and in gills and in Unio tumidus in the digestive gland, gills, mantle, foot as well as in the remaining tissue. The sGST was elevated for the entire exposure period in the whole mussel tissue of Dreissena polymorpha but despite higher basal activities in digestive gland and gills of Unio tumidus, it was rather inhibited or unaltered in most of their tissues. Elevated SOD activity indicated oxidative stress response in Dreissena polymorpha, but not in Unio tumidus. The CAT activity was barely affected in both species, rather inhibited in Unio tumidus, despite again higher basal activities in digestive gland and remaining tissue. Compared to the indigenous Unio tumidus, the investigated biotransformation and oxidative stress combating enzymes respond stronger in the invasive Dreissena polymorpha.

Cyanobacterial blooms and their corresponding toxins are a major concern to human health when surface waters of eutrophicated lakes are the only source for drinking water supply. The aim of the study was to test effective methods for cyanotoxin elimination by using the bioaccumulation potential of aquatic macrophytes in order to reduce microcystin LR (MC-LR) concentrations from raw lake surface water before entering the drinking water plant for further processing. Laboratory assays with aquatic macrophytes were performed in order to assess the most favorable species and optimal biomass for cyanotoxin elimination, where Lemna sp., Myriophyllum sp., and Hydrilla sp. were shown to be the most efficient macrophytes. In a second phase a pilot scale pond system (e.g. replica of the outdoor pond system) was constructed to assess the toxin elimination efficiency of 5.0 g L(-1) biomass of combined macrophytes. The applied macrophytic biomass reduced an initial MC-LR concentration of 12.1 and 9.2 microg L(-1) to values below the WHO guidelines for drinking water of 1.0 microg L(-1) (MC-LR) in only three days. Applying these results in a specially constructed outdoor pond system resulted in84% of toxin elimination at an initial concentration of 1.1 microg L(-1) MC-LR within the raw lake water.

We report the effects of 1,2- and 1,4-dichlorobenzene (1,2-DCB and 1,4-DCB) on the aquatic macrophyte Ceratophyllum demersum. We evaluated the response of the antioxidant system through the assay of glutathione reductase (GR), guaiacol peroxidase (POD) and glutathione peroxidase (GPx). Additionally, the effect of DCBs on the detoxication system by measuring the activity of glutathione-S-transferase (GST) was evaluated. C. demersum showed elevated GST activities when exposed to 10 and 20 mg l-1 1,2-DCB, and at 10 mg l-1 for 1,4-DCB. These results show that glutathione conjugation take place at relatively high concentrations of both isomers. Significantly increased activities of POD were also detected in C. demersum exposed to concentrations above 5 mg l-1 of the corresponding isomer. The GR activity was enhanced in plants exposed to 1,2-DCB (5 mg l-1) and 1,4-DCB (10 mg l-1). GPx was also significantly increased in exposures to the corresponding isomer, each at a concentration of 10 mg l-1. However, plants exposed to low doses of 1,4-DCB (1 mg l-1) showed significantly decreased activities of both enzymes GR and GPx. Consequently, it is clear that the exposure of the aquatic macrophyte C. demersum to DCBs is able to cause an activation of the antioxidant system, showing an isomer specific pattern, which suggests that the defence system of this plant is playing an important role in scavenging ROS, helping to protect the organism against adverse oxidative effects generated by the prooxidant action of the tested xenobiotics. Furthermore, increased GST activities give indirect evidence on the conjugation of either DCBs or the corresponding metabolites during phase II of detoxication, which supports the elimination process of toxic metabolites from cells of C. demersum. © 2007 Elsevier Ltd. All rights reserved. Fil: Monferran, Magdalena Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; Argentina Fil: Wunderlin, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; Argentina Fil: Nimptsch, Jorge. Leibniz Institute of Freshwater Ecology and Inland Fisheries. Berlin; Alemania Fil: Pflugmacher, Stephan. Leibniz Institute of Freshwater Ecology and Inland Fisheries. Berlin; Alemania

The effect of increased ammonia content on sub-acute biochemical responses was assessed in the rooted submersed aquatic macrophyte Myriophyllum mattogrossense (common name: "Brazil Milfoil" or "Matogrosso Milfoil"), in a seven day aquarium experiment. The pH and temperature were monitored in order to determine the proportions of both ionized (NH4+) and un-ionized (NH3) forms of ammonia. Specific activities of several enzymes such as catalase (CAT), guaiacol peroxidase (POD), glutathione peroxidase (GPx) and glutathione S-transferase (GST's) were measured as well as the content of the soluble antioxidant glutathione and lipid peroxidation were determined as these parameters are considered as indicators of cell-level disorder. The results showed that ammonia is able to generate oxidative stress, expressed through an elevated GSH content and the enhancement of CAT, POD, GPx and GST's activities in treatments with elevated ammonia content. As the toxic mechanism of ammonia is a complex phenomenon, this work adds an additional point of view to explain in parts the oxidative stress generating effect of ammonia promoting oxidative stress. Additionally the different modes of action proposed by other research groups are discussed, thus trying to combine the various points of view.

Agricultural land covers approximately 40% of Earth’s land surface and affects hydromorphological, biogeochemical and ecological characteristics of fluvial networks. In the northern temperate region, agriculture also strongly affects the amount and molecular composition of dissolved organic matter (DOM), which constitutes the main vector of carbon transport from soils to fluvial networks and to the sea and is involved in a large variety of biogeochemical processes. Here, we provide first evidence about the wider occurrence of agricultural impacts on the concentration and composition of fluvial DOM across climate zones of the northern and southern hemispheres. Both extensive and intensive farming altered fluvial DOM towards a more microbial and less plant-derived composition. Moreover, intensive farming significantly increased dissolved organic nitrogen (DON) concentrations. The DOM composition change and DON concentration increase differed among climate zones and could be related to the intensity of current and historical nitrogen fertilizer use. As a result of agriculture intensification, increased DON concentrations and a more microbial-like DOM composition likely will enhance the reactivity of catchment DOM emissions, thereby fuelling the biogeochemical processing in fluvial networks and resulting in higher ecosystem productivity and CO2 outgassing.