Characterization of complex groundwater flows in the environment of singular buildings by combining hydrogeological and non-destructive geophysical (ground-penetrating radar) techniques: Punta Begoña Galleries (Getxo,Spain)

Locating and quantifying groundwater flow in many built-up areas are a priority with regard to its complete restoration. In this work, a hydrogeological survey of the surroundings of the Punta Begoña Galleries (Getxo, Bizkaia), built on a coastal cliff, was completed by using ground penetrating radar (GPR) testing. Thus, the preliminary characterization of soils and rocks in accessible areas of the cliff was first improved by hydrogeological information gathered from a single survey borehole, including permeability measurements by low pressure injection tests (LPTs) and continuous water level monitoring. As a complementary method, the non-destructive GPR technique was performed during both dry and wet hydrological periods and in tandem with the injection tests, providing more complete spatial and temporal images of water flows. Specifically, GPR allows mapping of flow paths in soils and assessing the continuity of fractures in rock masses. Altogether, this complementary approach provides greater knowledge of complex underground flow dynamics in built environments, thus making it easier to make decisions for their management.     

Effects of self-attraction and loading at a regional scale: a test case for the Northwest European Shelf

The impact of the self-attraction and loading effect (SAL) in a regional 2D barotropic tidal model has been assessed, a term with acknowledged and well-understood importance for global models but omitted for boundary-forced, regional models, for which the implementation of SAL is non-trivial due to its non-local nature. In order to understand the impact of the lack of SAL effects in a regional scale, we have forced a regional model of the Northwest European Continental Shelf and the North Sea (continental shelf model (CSM)) with the SAL potential field derived from a global model (GTSM), in the form of a pressure field. Impacts have been studied in an uncalibrated setup and with only tidal forcing activated, in order to isolate effects. Additionally, the usually adopted simple SAL parameterization, in which the SAL contribution to the total tide is parameterized as a percentage of the barotropic pressure gradient (typically chosen 10%), is also implemented and compared to the results obtained with a full SAL computation. A significant impact on M2 representation is observed in the English Channel, Irish Sea and the west (UK East coast) and south (Belgian and Dutch Coast) of the North Sea, with an impact of up to 20 cm in vector difference terms. The impact of SAL translates into a consistent M2 amplitude and propagation speeds reduction throughout the domain. Results using the beta approximation, with an optimal domain-wide constant value of 1.5%, show a somewhat comparable impact in phase but opposite direction of the impact in amplitude, increasing amplitudes everywhere. In relative terms, both implementations lead to a reduction of the tidal representation error in comparison with the reference run without SAL, with the full SAL approach showing further impacted, improved results. Although the overprediction of tidal amplitudes and propagation speeds in the reference run might have additional sources like the lack of additional dissipative processes and non-considered bottom friction settings, results show an overall significant impact, most remarkable in tidal phases. After showing evidence of the SAL impact in regional models, the question of how to include this physical process in them in an efficient way arises, since SAL is a non-local effect and depends on the instantaneous water levels over the whole ocean, which is non-trivial to implement.     

Response of single benthic metrics and multi-metric methods to anthropogenic pressure gradients, in five distinct European coastal and transitional ecosystems

In recent times many benthic indices have been proposed to assess the ecological quality of marine waters worldwide. In this study we compared single metrics and multi-metric methods to assess coastal and transitional benthic status along human pressure gradients in five distinct environments across Europe: Varna bay and lake (Bulgaria), Lesina lagoon (Italy), Mondego estuary (Portugal), Basque coast (Spain) and Oslofjord (Norway). Hence, 13 single metrics (abundance, number of taxa, and several diversity and sensitivity indices) and eight of the most common indices used within the European Water Framework Directive (WFD) for benthic assessment were selected: index of size spectra (ISS), Benthic assessment tool (BAT), Norwegian quality index (NQI), Multivariate AMBI (M-AMBI), Benthic quality index (BQI), (Benthic ecosystem quality index (BEQI), Benthic index based on taxonomic sufficiency (BITS), and infaunal quality index (IQI). Within each system, sampling sites were ordered in an increasing pressure gradient according to a preliminary classification based on professional judgement. The different indices are largely consistent in their response to pressure gradient, except in some particular cases (i.e. BITS, in all cases, or ISS when a low number of individuals is present). Inconsistencies between indicator responses were most pronounced in transitional waters (i.e. IQI, BEQI), highlighting the difficulties of the generic application of indicators to all marine, estuarine and lagoonal environments. However, some of the single (i.e. ecological groups approach, diversity, richness) and multi-metric methods (i.e. BAT, M-AMBI, NQI) were able to detect such gradients both in transitional and coastal environments, being these multi-metric methods more consistent in the detection than single indices. This study highlights the importance of survey design and good reference conditions for some indicators. The agreement observed between different methodologies and their ability to detect quality trends across distinct environments constitutes a promising result for the implementation of the WFD’s monitoring plans. Moreover, these results have management implications, regarding the dangers of misclassification, uncertainty in the assessment, use of conflicting indices, and testing and validation of indices.     

Statistical method of precipitation prediction

Precipitation records from Salamanca (Spain) are being analyzed to detect temporal oscillations. This paper shows a method to identify these signals in order to determine the behaviour of the precipitation time series in this region.     

Cell and tissue biomarkers in mussel, and histopathology in hake and anchovy from Bay of Biscay after the Prestige oil spill (Monitoring Campaign 2003)

In order to assess the biological effects of the Prestige oil spill (POS), mussels (Mytilus galloprovincialis), European hake (Merluccius merluccius) and European anchovy (Engraulis encrasicolus) were sampled between April and September 2003 in various geographical areas of Bay of Biscay: Galicia, Central Cantabrian and East Cantabrian. In mussels, several cell and tissue biomarkers were measured: peroxisome proliferation as induction of acyl-CoA oxidase (AOX) activity, lysosomal responses as changes in the structure (lysosomal volume density, V(V(L)), surface-to-volume ratio, S/V(L), and numerical density, N(V(L))) and in membrane stability (labilization period, LP), cell type replacement as relative proportion of basophilic cells (volume density of basophilic cells, V(V(BAS))) in digestive gland epithelium, and changes in the morphology of digestive alveoli as mean luminal radius to mean epithelial thickness (MLR/MET). Additionally, flesh condition index (FCI) and gonad index (GI) were measured as supporting parameters. In hake and anchovy, liver histopathology was examined to determine the prevalence of parasites, melanomacrophage centers, non-specific lesions (inflammatory changes, atrophy, necrosis, apoptosis), early non-neoplastic toxicopathic lesions (i.e., hepatocellular nuclear polymorphism), foci of cellular alteration, benign and malignant neoplasms. In mussels, AOX induction was noticeable in April except in Galicia. LP values were low in all the geographical areas studied, indicating disturbed health, especially in Galicia. Alike, lysosomal enlargement was observed in most stations as shown by the extremely low S/V(L) values. V(V(BAS)) and MLR/MET values were markedly high. Overall, employed biomarkers detected exposure to toxic chemicals and disturbed health in mussels from Bay of Biscay, with impact decreasing from April to September. Although hepatocellular nuclear polymorphism and nematode parasitization in fish liver were remarkably prominent in some areas, they cannot be hitherto related to POS, since we lack historical data to determine whether the prevalences found were normal or significantly raised after POS.     

Butyltin compounds,sterility and imposex assessment in Nassarius reticulatus (Linnaeus, 1758), prior to the 2008 European ban on TBT antifouling paints,within Basque ports and along coastal areas

Levels of imposex (superimposition of male characters, upon females) and the presence of sterile females are assessed in the gastropod Nassarius reticulatus (L.), at 35 locations in the Basque Country. At 18 of these localities, organotin bioaccumulation (tributyltin (TBT); dibutyltin; monobutyltin) was evaluated, using isotope dilution GC–ICP–MS. Higher imposex levels and TBT body burden were found in confined harbours, with large vessel traffic or the presence of an offshore fleet. The highest values were found for the port of Pasaia, near to a shipyard (a relative penis size index of up to 92%, and TBT body burden up to 405 ng g^?1 – given on a dry weight basis as Sn). Imposex effects were evaluated also in parasitized females, at some of the sampling sites. The percentage of presence of c-type Vas Deferens sequence stages (i.e., with vas deferens beginning at the oviduct opening) was higher in parasitized females. In turn, there was an absence of highly convoluted oviduct in parasitized females.     

Social multi-criteria evaluation as a decision support tool for integrated coastal zone management

Traditional top-down and technocratic approaches seem to be insufficient to tackle the many conflicts related to the sustainable use of natural resources. At the same time, reductionist and mono-disciplinary approaches lack the capacity to capture the complex interactions within evolving socio-ecological systems. Coastal zone management is an area that provides a clear example of such difficulties. In this paper we explore the scope of a participatory integrated assessment process, known as Social Multi-Criteria Evaluation (SMCE), in the context of Integrated Coastal Zone Management (ICZM). Through a two-year collaborative research process, between an interdisciplinary group of researchers and a diverse group of stakeholders in the Urdaibai Estuary (a Biosphere Reserve in the Basque Country, Northern Spain), we show that improving the integration of diverse expertise and values can lead, through a mutual learning process, to the definition of relevant policy options and sound decisions in the face of complexity, value conflict and unavoidable uncertainty.     

Eutrophication Assessment in Basque Estuaries: Comparing a North American and a European Method

Eutrophication in marine ecosystems is an important problem that requires an accurate assessment. Although Basque estuaries (northern Spain) have historically been under high anthropogenic pressure, no specific eutrophication assessment method had been applied in these waters. In this study, a method employed in the Basque Country (BC) to assess the ??risk of failing to achieve good ecological status?? under the requirements of the Water Framework Directive (WFD) was adapted to exclusively assess the risk of eutrophication. This method is based on the driver?Cpressure?Cstate?Cimpact?Cresponse approach. The results from this method (called WFD-BC method) were compared to the results from Assessment of Estuarine Trophic Status (ASSETS; a specific method developed in the US to assess estuarine trophic status in a pressure?Cstate?Cresponse approach). The nutrient pressure was better characterized with the WFD-BC method due to the local hydrographic conditions (i.e., small and river-influenced estuaries) that were not well accommodated by the ASSETS method. In contrast, the WFD-BC results for assessment of state generally reflected worse conditions than the results from the ASSETS method due to the different indicators employed and the way these are integrated in the WFD-BC method. Overall, the WFD-BC method showed a good potential to assess eutrophication. However, to improve it, a lower weight for the benthos and macroalgae is recommended for evaluating state.     

Phytoplankton pigments and epifluorescence microscopy as tools for ecological status assessment in coastal and estuarine waters, within the Water Framework Directive

Inverted microscopy is widespread employed for the analysis of phytoplankton composition within water quality monitoring networks. However, the analysis at the lowest taxonomical level is not always required for ecological status assessment. In addition, inverted microscopy can underestimate the small phytoplankton, and not always distinguish photoautotrophic from heterotrophic cells. In this study, as alternative tools, epifluorescence microscopy and High Performance Liquid Chromatography (HPLC) were employed to characterize phytoplankton communities within waters of different trophic condition. Epifluorescence microscopy confirmed its effectiveness to count the small phytoplankton. Furthermore, significant correlations between nutrients of anthropogenic origin and nanoplankton abundances were found. However, this technique resulted very time-consuming. HPLC together with the CHEMTAX program was more appropriate than inverted microscopy, in terms of cost-effectiveness. Also, the main variability patterns observed in the phytoplankton community structure by HPLC coincided with previous findings in the study area. Nevertheless, a rapid screening at the inverted microscope is recommended.