Alícia Navarro-Ortega

Managing the effects of multiple stressors on aquatic ecosystems under water scarcity. The GLOBAQUA project

Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts river ecosystems, threatens the services they provide, and it will force managers and policy-makers to change their current practices. The EU-FP7 project GLOBAQUA aims at identifying the prevalence, interaction and linkages between stressors, and to assess their effects on the chemical and ecological status of freshwater ecosystems in order to improve water management practice and policies. GLOBAQUA assembles a multidisciplinary team of 21 European plus 2 non-European scientific institutions, as well as water authorities and river basin managers. The project includes experts in hydrology, chemistry, biology, geomorphology, modelling, socio-economics, governance science, knowledge brokerage, and policy advocacy. GLOBAQUA studies six river basins (Ebro, Adige, Sava, Evrotas, Anglian and Souss Massa) affected by water scarcity, and aims to answer the following questions: how does water scarcity interact with other existing stressors in the study river basins? How will these interactions change according to the different scenarios of future global change? Which will be the foreseeable consequences for river ecosystems? How will these in turn affect the services the ecosystems provide? How should management and policies be adapted to minimise the ecological, economic and societal consequences? These questions will be approached by combining data-mining, field- and laboratory-based research, and modelling. Here, we outline the general structure of the project and the activities to be conducted within the fourteen work-packages of GLOBAQUA.

Accumulation of perfluoroalkyl substances in human tissues.

Perfluoroalkyl substances (PFASs) are environmental pollutants with an important bioaccumulation potential. However, their metabolism and distribution in humans are not well studied. In this study, the concentrations of 21 PFASs were analyzed in 99 samples of autopsy tissues (brain, liver, lung, bone, and kidney) from subjects who had been living in Tarragona (Catalonia, Spain). The samples were analyzed by solvent extraction and online purification by turbulent flow and liquid chromatography coupled to tandem mass spectrometry. The occurrence of PFASs was confirmed in all human tissues. Although PFASs accumulation followed particular trends depending on the specific tissue, some similarities were found. In kidney and lung, perfluorobutanoic acid was the most frequent compound, and at highest concentrations (median values: 263 and 807ng/g in kidney and lung, respectively). In liver and brain, perfluorohexanoic acid showed the maximum levels (median: 68.3 and 141ng/g, respectively), while perfluorooctanoic acid was the most contributively in bone (median: 20.9ng/g). Lung tissues accumulated the highest concentration of PFASs. However, perfluorooctane sulfonic acid and perfluorooctanoic acid were more prevalent in liver and bone, respectively. To the best of our knowledge, the accumulation of different PFASs in samples of various human tissues from the same subjects is here reported for the very first time. The current results may be of high importance for the validation of physiologically based pharmacokinetic models, which are being developed for humans. However, further studies on the distribution of the same compounds in the human body are still required.

Pesticide monitoring in the basin of Llobregat River (Catalonia, Spain) and comparison with historical data

Through an extensive sampling in the Llobregat River basin, the presence of 50 currently used pesticides in water, sediment, and biota was assessed. Pesticides were detected primarily in water (up to 56% of the analytes), whereas their presence in sediments was more intermittent, and in biota was scarce. Those at high concentrations in water were the benzimidazoles (carbendazim in 22% of the samples up to 697 ng L(-1)), the organophosphorus (malathion in 54% of the samples up to 320 ng L(-1)), and the ureas (diuron in 54% of the samples up to 159 ng L(-1)). However, this pattern differed in sediments and biota, which were contaminated primarily with organophosphorus (higher Kow) (chlorpyrifos 93% of sediments up to 131 ng g(-1)). According to the results of this study, pesticide residues in the Llobregat River basin do not seem to represent a high risk to biota, even though some algae and fish can be affected. Nevertheless, the monitoring program can be very useful to control the contamination of the river basin, as the availability of historical data on the basin confirmed background contamination in the last 20 years.

Pesticides in the Ebro River basin: Occurrence and risk assessment ☆

In this study, 50 pesticides were analyzed in the Ebro River basin in 2010 and 2011 to assess their impact in water, sediment and biota. A special emphasis was placed on the potential effects of both, individual pesticides and their mixtures, in three trophic levels (algae, daphnia and fish) using Risk Quotients (RQs) and Toxic Units (TUs) for water and sediments. Chlorpyrifos, diazinon and carbendazim were the most frequent in water (95, 95 and 70% of the samples, respectively). Imazalil (409.73 ng/L) and diuron (150 ng/L) were at the highest concentrations. Sediment and biota were less contaminated. Chlorpyrifos, diazinon and diclofenthion were the most frequent in sediments (82, 45 and 21% of the samples, respectively). The only pesticide detected in biota was chlorpyrifos (up to 840.2 ng g(-1)). Ecotoxicological risk assessment through RQs showed that organophosphorus and azol presented high risk for algae; organophosphorus, benzimidazoles, carbamates, juvenile hormone mimic and other pesticides for daphnia, and organophosphorus, azol and juvenile hormone mimics for fish. The sum TUsite for water and sediments showed values < 1 for the three bioassays. In both matrices, daphnia and fish were more sensitive to the mixture of pesticide residues present.

Identifying major pesticides affecting bivalve species exposed to agricultural pollution using multi-biomarker and multivariate methods

The aim of this investigation was to identify major pesticides that may cause detrimental effects in bivalve species affected by agricultural pollution. Investigations were carried out using freshwater clams (Corbicula fluminea) transplanted in the main drainage channels that collect the effluents coming from agriculture fields in the Ebro Delta (NE Spain) during the main growing season of rice (from May to August). Environmental hazards were assessed by measuring simultaneous up 46 contaminant levels and 9 biomarker responses. Measured biological responses showed marked differences across sites and months. Antioxidant and esterase enzyme responses were in most cases inhibited. Lipid peroxidation levels increased steadily from May in upstream stations to August in drainage channels. Principal Component (PCA) and Partial Least Squares to Latent Structure regression (PLS) analyses allowed the identification of endosulfan, propanil, and phenylureas as being the chemical contaminants causing the most adverse effects in the studied species.

Assessing and forecasting the impacts of global change on Mediterranean rivers. The SCARCE Consolider project on Iberian basins

IntroductionThe Consolider-Ingenio 2010 project SCARCE, with the full title “Assessing and predicting effects on water quantity and quality in Iberian Rivers caused by global change” aims to examine and predict the relevance of global change on water availability, water quality, and ecosystem services in Mediterranean river basins of the Iberian Peninsula, as well as their socio-economic impacts. Starting in December 2009, it brought together a multidisciplinary team of 11 partner Spanish institutions, as well as the active involvement of water authorities, river basin managers, and other relevant agents as stakeholders.MethodsThe study areas are the Llobregat, Ebro, Jucar, and Guadalquivir river basins. These basins have been included in previous studies and projects, the majority of whom considered some of the aspects included in SCARCE but individually. Historical data will be used as a starting point of the project but also to obtain longer time series. The main added value of SCARCE project is the inclusion of scientific disciplines ranging from hydrology, geomorphology, ecology, chemistry, and ecotoxicology, to engineering, modeling, and economy, in an unprecedented effort in the Mediterranean area. The project performs data mining, field, and lab research as well as modeling and upscaling of the findings to apply them to the entire river basin.ResultsScales ranging from the laboratory to river basins are addressed with the potential to help improve river basin management. The project emphasizes, thus, linking basic research and management practices in a single framework. In fact, one of the main objectives of SCARCE is to act as a bridge between the scientific and the management and to transform research results on management keys and tools for improving the River Basin Management Plans. Here, we outline the general structure of the project and the activities conducted within the ten Work Packages of SCARCE.

Assessing the effects of multiple stressors on the functioning of Mediterranean rivers using poplar wood breakdown

Mediterranean rivers in the Iberian Peninsula are being increasingly affected by human activities, which threaten their ecological status. A clear picture of how do these multiple stressors affect river ecosystem functioning is still lacking. We addressed this question by measuring a key ecosystem process, namely breakdown of organic matter, at 66 sites distributed across Mediterranean Spain. We performed breakdown experiments by measuring the mass lost by wood sticks for 54 to 106 days. Additionally, we gathered data on physico-chemical, biological and geomorphological characteristics of study sites. Study sites spanned a broad range of environmental characteristics and breakdown rates varied fiftyfold across sites. No clear geographic patterns were found between or within basins. 90th quantile regressions performed to link breakdown rates with environmental characteristics included the following 7 variables in the model, in decreasing order of importance: altitude, water content in phosphorus, catchment area, toxicity, invertebrate-based biotic index, riparian buffer width, and diatom-based quality index. Breakdown rate was systematically low in high-altitude rivers with few human impacts, but showed a high variability in areas affected by human activity. This increase in variability is the result of the influence of multiple stressors acting simultaneously, as some of these can promote whereas others slow down the breakdown of organic matter. Therefore, stick breakdown gives information on the intensity of a key ecosystem process, which would otherwise be very difficult to predict based on environmental variables.

Persistent Organic Pollutants in Water, Sediments, and Biota in the Ebro River Basin

The Ebro river basin is one of the most studied basins in Spain. The Confederacion Hidrografica del Ebro (CHE), which is the organization in charge of the management of the basin, has different control networks that are operative since 1992. Besides these control networks, there is also a contribution of scientific studies since 1988 to know the distribution of persistent organic pollutants in the basin. Most of these studies are site specific or consider only one family of compounds. Recently, some scientific studies have focused on the basin as a whole, considering several compounds and matrices.

River conservation under multiple stressors: Integration of ecological status, pollution and hydrological variability

Rivers are receivers of chemical stressors from anthropogenic origin, including organic matter and inorganic nutrients (phosphorus, nitrogen), and many organic contaminants such as pesticides, pharmaceuticals, perfluorinated compounds surfactants or metals as well as newly discovered emerging risks like metal and carbon-based nanomaterials and microplastics. In impaired rivers other stressors also come to play and co-occur with these chemicals, with specific effects and different manifestation in time and space. Amongst these stressors, habitat alteration, interruption of flow water regime, or higher water temperature, complicate the survival and life cycle of organisms, especially of those sensitive, and are at the base of local extinctions and the overall decrease of biodiversity. In impaired rivers these emerging contaminants and risks mix up with nutrients in excess, or with abundant dissolved organic matter, especially in systems heavily impacted by industrial, agricultural and urban effluents, making up a complex co-occurrence of stressors with effects on biological communities difficult to attribute to any of them. It is the so-called multiple-stress situation. The combination of stressors can have deleterious effects on freshwater ecosystems althoughmost current knowledge is limited to the effects of single stressors on the chemical and ecological status of water bodies and on ecosystem functioning. One of the pioneering projects in Europe devoted to multiple stressors was NOMIRACLE (Novel methods for integrated risk assessment of cumulative stressors). A selection of the scientific results of this project were published in Science of the Total Environment 408 (2010) 3719– 3724. During the development of NOMIRACLE, from the years 2004– 2009, probably the first and the largest integrated multi-stressors EU project, it was already evidenced that the focus on “chemical cocktails” should be replaced by the focus on the biological receptors and “stressor cocktails”. Holmstrup et al. (2010) in the same special issue summarized three core problems to be tackled: 1) the need to define themost potent combinations of natural and chemical stressors, 2) the importance to address the exposure sequence to stressors, and 3) the need to move from short-term laboratory tests to field validation by means of mesocosm studies. Simultaneously, Hering et al. (2010), published also in Science of the Total Environment, formulated the concept of “emerging stressors” in addition to the so-called “traditional stressors” like eutrophication. Under this framework, climate change, emerging substances, habitat deterioration, direct hydrological alteration, and invasive species are to be considered. It is the cumulative impact of the multiple stressors which together affect structure (biodiversity), functioning, and health of ecosystems and species. One of the key stressors

Stressors in Mediterranean River Basins under water scarcity.

Water has become a precious resource on which the welleing and even the survival of future generations critically depend. round the world, there are many warnings that human water use xceeds supportable levels. Groundwater depletion, low or nonxisting river flows, and worsening contamination levels are among he more palpable indicators. Consequently, issues relating to water uch as quality, quantity, availability, planning and management ill have to be seriously tackled now and in the future. Currently most freshwater systems in Europe are threatened y a variety of stressors (organic and inorganic pollution, geomorhological alterations, changes in land uses, climate variability and hange, water abstraction, invasive species and pathogens). Stressrs are of diverse nature but cause adverse effects on organisms and cosystems. Ultimately, these effects threaten water quality and iological diversity of European water bodies, which has important conomic consequences. Most ecosystems are exposed simultaneously to several stressrs, in the so-called multiple-stress situations. In some cases tressors may act independently to each other, in some others hey interact, thus leading to synergistic/antagonistic effects, either irectly (if acting on the same target) or indirectly (if acting on diferent targets). The combination of stressors can have deleterious ffects on freshwater ecosystems although most current knowldge is limited to the effects of single stressors on the chemical and cological status of water bodies and on ecosystem functioning. Some stressors such as water scarcity can limit biodiversity nd economic activities in entire regions. In addition of being a tressor on its own, water scarcity can drive the effects of other tressors acting upon river ecosystems. It leads to intermittency n water flow, and therefore has implications for hydrologic conectivity, negative side-effects on biodiversity, water quality, and iver ecosystem functioning. Water scarcity can amplify the effects f water pollution by reducing the natural diluting capacity of ivers. Interactions between stressors may be exacerbated by cliate change. For instance, warmer temperatures and reduced river ows will likely increase the physiological burden of pollution on he aquatic biota, and biological feedback between stressors (e.g. limate change and nutrient pollution) may produce unexpected utcomes. Degradation of drainage basins, destruction of natural abitats, over-exploitation of fish populations and other natural esources, or the establishment of invasive species, are factors hose impacts combine and may give rise to synergistic effects, specially during periods of water shortage. The effects of these tressors are very relevant for the chemical and ecological status of ater bodies as well as for the sustainability of ecosystem services hey provide.