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Using a long-term (1995–2014) monitoring network, from 51 sampling stations in estuaries and coasts of the Basque Country (Bay of Biscay), the objective of this investigation was to assess the responsiveness of 83 variables in water (18), sediments (27), biota (26), phytoplankton (2), macroinvertebrates (5) and fishes (5) to different human pressures and management actions. We used a total of 3247 series of data to analyse trends of improvement and worsening in quality. In a high percentage of the cases, the management actions taken have resulted in positive effects in the environment, as shown by the trend analysis in this investigation. Overall, much more trends of improvement than of worsening have been observed; this is true for almost all the media and biological components studied, with the exception of phytoplankton; and it applies as well to almost all the stations and water bodies, with the exception of those corresponding to areas with water treatment pending of accomplishment. In estuaries with decreasing human pressures during the period, the percentage of series showing quality improvement was higher (approx. 30%) than those showing worsening of quality (12%). Moreover, in those water bodies showing an increase of pressure, variables which can be considered indicators of anthropogenic effects showed negative trends (quality worsening). On the other hand, some of the variables analysed were more affected by natural variability than by changes in pressures. That was the case of silicate, nitrate and suspended solids, which followed trends correlated to salinity, which, in turn, was related to the rainfall regime during the study period. [ABSTRACT FROM AUTHOR]

Highlights: [•] Setting the benthic maximum ecological potential (MEP) is an important task. [•] Modelling is used to set MEP before and after morphological changes (harbour). [•] Benthic richness and diversity can be modelled, knowing environmental factors. [•] We propose using as benthic MEP 75% of the natural reference conditions. [Copyright &y& Elsevier]

Regional Sediment Quality Guidelines (SQG) for metals from the Basque Country (northern Spain) were determined. These guidelines are proposed to be used for management purposes, within the Water Framework Directive (WFD). SQG were determined on the basis of sediment chemistry, toxicity and benthic community disturbance, from 961 estuarine and coastal samples. The guidelines were calculated using a percentile approach (effect and non-effect data), following normalisation on the fine-sediment content and with non-normalisation. The feasibility of SQG was quantified by the incidence of adverse effects, that is, the ratio of effect/no-effect data, which increased significantly with increasing SQG ranges. The study proposes the following formula to calculate SQG: SQG  μg·g−1/FC. 10−2 (where FC is fine-sediment content and SQG* is the normalised SQG). The SQG* were 13.5 μg·g−1 for As, 1 μg·g−1 for Cd, 39 μg·g−1 for Cr, 55 μg·g−1 for Cu, 0.53 μ g·g−1 for Hg, 23 μg·g−1 for Ni, 78 μ g·g−1 for Pb and 249 μg·g−1 for Zn. The use of four different organisational biological levels ensures an improvement in the determination of metal regional SQG for the assessment of the chemical and physicochemical status in marine waters, within the WFD. [ABSTRACT FROM AUTHOR]

Abstract: Tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) were measured in surficial sediments at, the ports of Pasaia and Bilbao, together with other mid- and small-size harbours of the Basque Country (northern Spain), in 2007–2008. The highest values of the sum of the three measured butyltin species (3523–3640ngg−1, as Sn) were found at sampling stations near to shipyards located within the port of Pasaia. The highest value of TBT concentration (3143ngg−1, as Sn) was found at the marina of Getxo, in the port of Bilbao. The degree of TBT degradation varied greatly between sampling stations, being found to be generally higher in those sediments with higher values of redox potential and lower values of TBT concentration (normalized by organic matter content). [Copyright &y& Elsevier]

Abstract: The European Water Framework Directive (WFD) establishes a framework for the protection and improvement of estuarine (transitional) and coastal waters, attempting to achieve good water status by 2015; this includes, within the assessment, biological and chemical elements. The European Commission has proposed a list of priority dangerous substances (including metals such as Cd, Hg, Ni and Pb), with the corresponding list of environmental quality standards (EQS), to assess chemical status, but only for waters. In this contribution, a long-term (1995–2007) dataset of transitional and coastal water and sediment trace elements concentrations, from the Basque Country (northern Spain), has been used to investigate the response of these systems to water treatment programmes. Moreover, the approach proposed in the WFD, for assessing water chemical status (the ‘one out, all out’ approach), is compared with the integration of water and sediment data, into a unique assessment. For this exercise, background levels are used as reference conditions, identifying the boundary between high and good chemical status. EQS are used as the boundary between good and moderate chemical status. This contribution reveals that the first approach can lead to misclassification, with the second approach representing the pattern shown by the long-term data trends. Finally, the management implications, using each approach are discussed. [Copyright &y& Elsevier]

Levels of imposex (superimposition of male characters, upon females) and the presence of sterile females are assessed in the gastropod Nassarius nitidus (Jeffreys, 1867), at 22 locations in the Basque Country (northern Spain). At 18 of these localities, butyltin bioaccumulation (tributyltin (TBT); dibutyltin; monobutyltin) was analysed using isotope dilution and GC¿ICP-MS. Higher imposex levels and TBT body burden were found in confined harbours, with a large vessel traffic or the presence of a fishing fleet or a shipyard. For the first time, four apparently sequential types of aborted capsules are described in this species. Another novelty is the interspecific comparison between imposex intensities in sympatrically living populations of N. nitidus and N. reticulatus. This showed that sensitivity to TBT pollution of both species is relatively similar (in terms of Relative Penis Length Index). Since N. nitidus has a restricted habitat distribution due to its low presence in wave-exposed habitats, its complementary use with other species is recommended for its use in TBT monitoring programmes. [Copyright &y& Elsevier]

Abstract: The European Water Framework Directive (WFD) establishes a framework for the protection of groundwater, inland surface waters, estuarine waters, and coastal waters. The WFD constitutes a new view of water resources management in Europe, based mainly upon ecological elements; its final objective is achieving at least ‘good ecological quality status’ for all water bodies by 2015. The approach to identify these water bodies includes, amongst others, the sub-division of a water body into smaller water bodies, according to pressures and resulting impacts. The analyses of pressures and impacts must consider how pressures would be likely to develop, prior to 2015, in ways that would place water bodies at risk of failing to achieve ecological good status, if appropriate programmes of measures were not designed and implemented. This contribution focuses on the use of the DPSIR (Driver, Pressure, State, Impact, Response) approach, in assessing the pressures and risk of failing the abovementioned objective, using the Basque (northern Spain) estuarine and coastal waters as a case study, using the following steps: (i) determination of the water bodies to be analysed; (ii) identification and description of the driving forces producing pressures over the region; (iii) identification of all existing pressures within the water bodies; (iv) identification, from them, of the most relevant pressures; (v) determination, from the relevant pressures, of those which are significant; (vi) assessing the impacts on water bodies (in terms of ecological and chemical impacts); and (vii) assessing the risk of failing the WFD objectives. [Copyright &y& Elsevier]

Abstract: 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 405ngg−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. [Copyright &y& Elsevier]

Abstract: Recent environmental legislation, worldwide, aims to restore and protect the quality of the marine environment. Within this context, in order to maintain the good functioning of marine ecosystems, sediment pollution monitoring is becoming increasingly important. Hence, for this contribution, the spatial distribution of Cd, Fe, Hg, Mn, Ni and Pb accumulation areas were determined, for the sediments of the Basque continental shelf. Statistically-assisted Geographical Information System (GIS)-mapping techniques were used, in order to infer the processes responsible for such accumulations. Differences in contaminant entrance pathways were observed between sectors. However, hydrodynamic conditions favored the rapid dispersal of contaminants and their stable distribution. The methodology used resulted in a suitable approach for identifying contaminant distribution patterns, which could be used in environmental assessment processes. Nevertheless, an important knowledge gap on the distribution of contaminants in offshore sediments was identified. Extensions of actual monitoring programs are suggested, in order to improve the information available for identifying the behavior and process-drivers for contaminants in offshore systems. This would permit the achievement of a more complete approach, to understand the effects of land-derived contaminants, on offshore systems. [Copyright &y& Elsevier]

Abstract: Global climate models have predicted a rise on mean sea level of between 0.18 m and 0.59 m by the end of the 21st Century, with high regional variability. The objectives of this study are to estimate sea level changes in the Bay of Biscay during this century, and to assess the impacts of any change on Basque coastal habitats and infrastructures. Hence, ocean temperature projections for three climate scenarios, provided by several atmosphere–ocean coupled general climate models, have been extracted for the Bay of Biscay; these are used to estimate thermosteric sea level variations. The results show that, from 2001 to 2099, sea level within the Bay of Biscay will increase by between 28.5 and 48.7 cm, as a result of regional thermal expansion and global ice-melting, under scenarios A1B and A2 of the Intergovernmental Panel on Climate Change. A high-resolution digital terrain model, extracted from LiDAR, data was used to evaluate the potential impact of the estimated sea level rise to 9 coastal and estuarine habitats: sandy beaches and muds, vegetated dunes, shingle beaches, sea cliffs and supralittoral rock, wetlands and saltmarshes, terrestrial habitats, artificial land, piers, and water surfaces. The projected sea level rise of 48.7 cm was added to the high tide level of the coast studied, to generate a flood risk map of the coastal and estuarine areas. The results indicate that 110.8 ha of the supralittoral area will be affected by the end of the 21st Century; these are concentrated within the estuaries, with terrestrial and artificial habitats being the most affected. Sandy beaches are expected to undergo mean shoreline retreats of between 25% and 40%, of their width. The risk assessment of the areas and habitats that will be affected, as a consequence of the sea level rise, is potentially useful for local management to adopt adaptation measures to global climate change. [Copyright &y& Elsevier]