Search

Macrobenthic organisms are useful bioindicators to assess ecological quality status. On the south-central coast of Peru (13°15.15′S, 76°18.5′W), a Liquefied Natural Gas (LNG) marine terminal has been operating since 2010. We investigated the macrobenthic communities and sediment parameters from 2011 to 2020 to evaluate the ecological quality status in the surrounding area of the marine terminal, using the AZTI Marine Biotic Index (AMBI) and its multivariate version (M-AMBI). We analyzed the diversity and community composition of macrobenthic invertebrates and the physico-chemical parameters of the sediment from 29 sampling sites, ranging from 0 to 15m depth. The sampling design considered: the direct influence zone ("DIZ", surroundings of the marine terminal), and northern (NCZ) and southern (SCZ) control zones. Our results indicated that abundance was high at SCZ and decreased with depth. Species richness and diversity were high at DIZ and NCZ, respectively, and increased up to 10m but dropped at 15m. High sand content was recorded in shallow depths, while in deeper areas and DIZ, mud and organic matter increased and redox potential was negative. AMBI indicated a "slightly disturbed" status in general, while M-AMBI indicated "good" or "moderate" status at depths ≤ 12m, and "poor" status at 15m. Overall, the season/year factor was not important, and variables were mostly significantly different across depths. Redox potential and organic matter were correlated with M-AMBI at 15m. In general, our results indicate an acceptable ecological quality surrounding the marine terminal, likely because the study area is not influenced by an important input of an anthropogenic stressor. This study highlights the importance of monitoring benthic communities in the surroundings of human-made structures and the use of ecological quality indices for understanding potential impacts. [Display omitted] • Macrobenthic communities and sediment parameters around an LNG marine terminal was studied from 2011 to 2020. • AMBI and calibrated M-AMBI were used to assess the ecological quality status around the marine terminal. • AMBI indicated a slightly disturbed status in the study area, but M-AMBI distinguished a degraded quality at deeper areas. • Overall, there was no evidence of an ecological impact attributable to the marine terminal. [ABSTRACT FROM AUTHOR]

Abstract: A cod farm in Vidlin Voe, Shetland was at the time of the study the largest cod farm in Europe, and was started in 2003. Run according to organic principles, the farm consisted of 17 ⁎ 32m diameter cages in the 3km long sea loch (locally known as voe), which though extremely exposed at the mouth, is sheltered near the cages. Benthic macrofauna and physical/chemical sediment parameters were measured in the summer months of 2004, 2005 and 2006 as biomass increased in the growing cycle. A range of biotic indices showed the benthic environment was enriched at peak biomass of the farm, but by contrast, surficial CHN levels and organic matter were low and uniform. The commonly used sediment indicators redox, total organic carbon and total organic nitrogen did not correlate well with biotic indicators at this site. Predictions from a near-field particle tracking and resuspension model (CODMOD) and a simple nutrient enhancement box model of the voe system (Equilibrium Concentration Enhancement (ECE) model), were used to assess the assimilative capacity of the system. [Copyright &y& Elsevier]

Abstract: The airborne laser scanning LIDAR (LIght Detection And Ranging) provides high-resolution Digital Terrain Models (DTM) that have been applied recently to the characterization, quantification and monitoring of coastal environments. This study assesses the contribution of LIDAR altimetry and intensity data, topographically-derived features (slope and aspect), and multi-spectral imagery (three visible and a near-infrared band), to map coastal habitats in the Bidasoa estuary and its adjacent coastal area (Basque Country, northern Spain). The performance of high-resolution data sources was individually and jointly tested, with the maximum likelihood algorithm classifier in a rocky shore and a wetland zone; thus, including some of the most extended Cantabrian Sea littoral habitats, within the Bay of Biscay. The results show that reliability of coastal habitat classification was more enhanced with LIDAR-based DTM, compared with the other data sources: slope, aspect, intensity or near-infrared band. The addition of the DTM, to the three visible bands, produced gains of between 10% and 27% in the agreement measures, between the mapped and validation data (i.e. mean producer''s and user''s accuracy) for the two test sites. Raw LIDAR intensity images are only of limited value here, since they appeared heterogeneous and speckled. However, the enhanced Lee smoothing filter, applied to the LIDAR intensity, improved the overall accuracy measurements of the habitat classification, especially in the wetland zone; here, there were gains up to 7.9% in mean producer''s and 11.6% in mean user''s accuracy. This suggests that LIDAR can be useful for habitat mapping, when few data sources are available. The synergy between the LIDAR data, with multi-spectral bands, produced high accurate classifications (mean producer''s accuracy: 92% for the 16 rocky habitats and 88% for the 11 wetland habitats). Fusion of the data enabled discrimination of intertidal communities, such as Corallina elongata, barnacles (Chthamalus spp.), and stands of Spartina alterniflora and Phragmites australis, which presented misclassification when conventional visible bands were used alone. All of these results were corroborated by the kappa coefficient of agreement. The high classification accuracy found here, selecting data sources, highlights the value of integrating LIDAR data with multi-spectral imagery for habitat mapping in the intertidal complex fringe. [Copyright &y& Elsevier]

Abstract: This contribution describes oceano-meteorological conditions, investigating their coupling, within the southeastern part of the Bay of Biscay. The study focuses upon: (i) simple relationships between atmospheric temperature and sea surface temperature (SST); (ii) complex relationships, such as the heat and salt content associated with the precipitation–evaporation balance and river flow; and (iii) dynamic aspects (Ekman transport, upwelling–downwelling conditions, turbulence and winter mixed layer depth), related to the wind speed and direction. Some seasons of the first five-year period of the 21st century have been defined as “extreme” (warm summer in 2003; cold and long winter in 2005; very dry spring and summer seasons in 2005; etc.). The present study confirms the presence of frequent seasonal anomalies; they appear to indicate a “deseasonalisation”, in relation to the classical seasonal cycle of the Atlantic climatic regime, at mid-latitudes. This term means that winter–summer duality prevails against the establishment (in terms of values and mean duration), of spring and autumn as transitional seasons. In contrast, oceano-meteorological time-series is characterised by its relatively scarce anomalies, in terms of annual values. In addition, a significant coupling between meteorological and oceanographic conditions is observed over the area, confirming that the meteorological forcing drives, to a great extent, oceanographic conditions at the sea surface; and water column properties, to a lesser degree. [Copyright &y& Elsevier]

The Bay of Biscay is a structurally complex region, exhibiting high biodiversity and productivity and hosting a wide variety of benthic habitats. Unfortunately, current scientific knowledge of deep-sea ecosystems is limited. Our investigation provides an updated vision of the existing knowledge on key aspects of the deep-sea ecosystem and identifies research priorities for the definition of a research roadmap in support of sustainable management, including the protection and conservation of deep-sea ecosystem of the Bay of Biscay. To achieve this, firstly a revision of projects, surveys and studies conducted in the region, was carried out resulting in the identification of 62 publicly available scientific documents. Secondly, an online survey was carried out, receiving 51 responses from 24 research institutions in 9 countries. Finally, a workshop was attended by 39 scientists to identify and discuss ways forward on deep-sea research in the Bay of Biscay. Results indicate that knowledge of benthic habitats, and vulnerable and sensitive habitats/species is good or very good for 45% of the respondents, while limited knowledge was reported for deep pelagic habitats. Almost 75% of the scientists agreed that deep-sea processes affect shallower areas. Funding (71%) and research vessel availability (57%) were considered the most constraining aspects limiting deep-sea research. More than 50% of the scientists perceived a short- or medium-term threat from human activities and pressures, while over than 40% of the respondents considered that there are no, or limited, data available to assess the environmental status. Regarding climate change, 55% of scientists partially or fully agreed with the existence of evidence of climate change effects, but 47% of them totally or partially considered that climate change monitoring is insufficient to assess eventual changes and effects. Most respondents (63%) considered that deep-sea ecosystems are not properly represented in the current Marine Protected Areas network. In terms of future needs, the development of monitoring strategies to reduce costs and guarantee an optimal design, data sharing and an increase in transnational collaboration are most cited. Finally, a proposal for a roadmap to fill in knowledge gaps for a better understating of the ecosystem processes of the deep sea of the Bay of Biscay is delivered. • Scientific knowledge of the deep-sea ecosystem in the Bay of Biscay is limited. • An updated vision of current knowledge on key aspects of the deep-sea ecosystem is provided. • Research priorities for the definition of a research roadmap are identified. • Intended to support sustainable management, protection and conservation. [ABSTRACT FROM AUTHOR]

Intertidal seagrasses often occupy areas of high ecological importance that are also targeted for human activities, such as shellfishing and leisure walking. These activities could affect the growth or survival of seagrass. The society at large lacks knowledge of the ecological relevance of seagrasses and their vulnerability, presenting an obstacle for their conservation. Here, the Oka estuary (Basque Country, N. Spain) is used as a case study to analyse the spatial extent of shellfishing activities in seagrass (Zostera noltei). This estuary holds 84% of the intertidal seagrass meadows present in the Basque Country and is visited during the year by professional and recreational shellfishers. Bait digging is legal year-round, and clam digging (by professionals only) from October to February. Human presence over 11 years averaged 17 people on the tidal flat in each daylight hours from August to October. Each professional shellfishing daily trip affected 7.4–21.6 m2 by fishing and 110–188 m2 by trampling in seagrass, but was substantially different between clam and bait (crustacean, worm) fishing. Scaling up this area to estimated annual number of shellfishers, 8–69% of the total seagrass area is trampled and 1–9% is dug per year. In comparison to a habitat suitability map for seagrass, 98% of trampling occurred within a very highly suitable area for seagrass presence (i.e., >90%). This pressure could adversely affect seagrass density and prevent the expansion of meadows into areas suitable for seagrass. Management of public impacts to seagrass in this estuary could occur through prohibition of some activities in seagrass and awareness campaigns among shellfishers and walkers. [Display omitted] • Seagrass surface is declining in the Basque estuaries. • Trampling and digging by shellfishers are the main perturbing human factors for Basque seagrasses. • Shellfishers trampling and digging on seagrasses is quantified for the Oka estuary. • Awareness-raising campaign and some banning measures are proposed to protect and conserve seagrasses in the Oka estuary. [ABSTRACT FROM AUTHOR]

Pockmarks are concave depressions on the sea bottom produced by fluid escape from subaqueous sediments which can be found worldwide in muddy and silt/clay sediments. Due to their morphological and geochemical characteristics, certain pockmarks play an important role in structuring benthic communities, and consequently, they have been proposed to be protected. The present research provides a characterisation of the benthic macrofauna composition in pockmark fields in the southeaster Bay of Biscay. A total of 11 samples were acquired in and close to pockmarks covering a range of depths of 414–992 m. The survey strategy considered the acquisition of one sample inside of each of the selected pockmarks and another sample near, but out of them. Collected macrofaunal organisms were identified at lowest taxonomical level (species) when possible, structural parameters were calculated and a hierarchical cluster analysis carried out with species data. Species density, biomass, richness, diversity and evenness were found to be higher in samples collected inside pockmarks in comparison to samples obtained outside but not statistically significant. This could be explained by the inactivity of the studied pockmarks, which do not offer/generate a particular environment with unusual characteristics that limit or enhance the development of specific species/groups with special traits. • Benthic macrofauna characterisation in pockmark fields in southeastern Bay of Biscay. • No significative differences were found among macrofauna inside/outside pockmarks. • Macrofaunal spatial variability is explained by grain size, organic matter and depth. [ABSTRACT FROM AUTHOR]

Aquatic biomonitoring has become an essential task in Europe and many other regions as a consequence of strong anthropogenic pressures affecting the health of lakes, rivers, oceans and groundwater. A typical assessment of the environmental quality status, such as it is required by European but also North American and other legislation, relies on matching the composition of assemblages of organisms identified using morphological criteria present in aquatic ecosystems to those expected in the absence of anthropogenic pressures. Through decade-long and difficult intercalibration exercises among networks of regulators and scientists in European countries, a pragmatic biomonitoring approach was developed and adopted, which now produces invaluable information. Nonetheless, this approach is based on several hundred different protocols, making it susceptible to issues with comparability, scale and resolution. Furthermore, data acquisition is often slow due to a lack of taxonomic experts for many taxa and regions and time-consuming morphological identification of organisms. High-throughput genetic screening methods such as (e)DNA metabarcoding have been proposed as a possible solution to these shortcomings. Such "next-generation biomonitoring", also termed "biomonitoring 2.0", has many advantages over the traditional approach in terms of speed, comparability and costs. It also creates the potential to include new bioindicators and thereby further improves the assessment of aquatic ecosystem health. However, several major conceptual and technological challenges still hinder its implementation into legal and regulatory frameworks. Academic scientists sometimes tend to overlook legal or socioeconomic constraints, which regulators have to consider on a regular basis. Moreover, quantification of species abundance or biomass remains a significant bottleneck to releasing the full potential of these approaches. Here, we highlight the main challenges for next-generation aquatic biomonitoring and outline principles and good practices to address these with an emphasis on bridging traditional disciplinary boundaries between academics, regulators, stakeholders and industry. [ABSTRACT FROM AUTHOR]

The implementation of directives such as the European Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD) has promoted the development of several tools and methods for assessing the ecological health of marine ecosystems. Within the scope of the WFD and in terms of rocky shores, several multimetric tools were developed based on the macroalgae biological quality element (BQE), in addition to those based on macroinvertebrates. The WFD requires member states to assess each BQE separately. The present work aimed to test the ability of ecological indices to distinguish sites within anthropogenic disturbance gradients caused by organic enrichment, using macroinvertebrate communities on intertidal rocky shores. Owing to the lack of more specific indices (for rocky shore), indices based on abundance, diversity and/or taxonomic composition were selected from several widely used indices in ecological studies and/or developed for soft-bottom macroinvertebrate communities. Present findings reveal several indices based on diversity and/or taxonomic composition able to distinguish sites within the disturbance gradients, showing increasing quality from the site nearest the source of organic enrichment to that farthest from it, especially indices calculated using biomass data, and in the summer season. Such results open good perspectives for the use of intertidal macroinvertebrate communities from rocky shores, and also help add the perspective of this biological quality element in the ecological quality assessment of coastal waters. [ABSTRACT FROM AUTHOR]

Estuaries and coasts are among the most productive ecosystems and constitute valuable habitats for biodiversity and ecosystem services. Amongst nearshore ecosystems, seagrass beds play a major role enhancing biodiversity and water quality. Consequently, the development of new approaches to create extensive and high-resolution habitat maps is required not only to implement conservation, restoration and management plans, but also to establish adaptation plans to face climate change impacts. This study particularly assesses the capability of hyperspectral airborne imagery acquired with Compact Airborne Spectrographic Imager (CASI) to discriminate and map estuarine habitats, with special focus on Zostera noltii seagrass meadows. To this end, 13 habitats were defined along the supralittoral, intertidal and subtidal zones of an estuary, including Z. noltii seagrass meadows. The CASI sensor was configured to acquire 25 bands in the visible and near infrared wavelengths with a ground sampling distance of 2 m. Spectral bands were selected for species discrimination based on the spectral signature of the different habitat classes. Six different band combinations were tested applying maximum likelihood classification algorithm. The most accurate classification was obtained with 10 band combination (a mean producer accuracy 92% and a mean user accuracy 94%). The classification of Z. noltii beds has been found to be restricted to moderate and high dense meadows, however a vegetation index has been defined which could be applied for mapping Z. noltii meadow cover. These results highlight the value of CASI data to discriminate and map estuarine habitats, providing key information to be used in supporting the implementation of environmental legislation, protection and conservation of coastal habitats. [ABSTRACT FROM AUTHOR]

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: One of the main adaptation strategies to global change scenarios, aiming to preserve ecosystem functioning and biodiversity, is to maximize ecosystem resilience. The resilience of a species metapopulation can be improved by facilitating connectivity between local populations, which will prevent demographic stochasticity and inbreeding. This investigation estimated the degree of connectivity among estuarine species along the north-eastern Iberian coast, in order to assess community vulnerability to global change scenarios. To address this objective, two connectivity proxy types have been used based upon genetic and ecological drift processes: 1) DNA markers for the bivalve cockle (Cerastoderma edule) and seagrass Zostera noltei, and 2) the decrease in the number of species shared between two sites with geographic distance. Neutral biodiversity theory predicts that dispersal limitation modulates this decrease, and this has been explored in estuarine plants and macroinvertebrates. Results indicate dispersal limitation for both saltmarsh plants and seagrass beds community and Z. noltei populations; this suggests they are especially vulnerable to expected climate changes on their habitats. In contrast, unstructured spatial pattern found in macroinvertebrate communities and in C. edule genetic populations in the area suggests that estuarine soft-bottom macroinvertebrates with planktonic larval dispersal strategies may have a high resilience capacity to moderate changes within their habitats. Our findings allow environmental managers to prioritize the most vulnerable species and habitats to be restored. [Copyright &y& Elsevier]

Abstract: Intertidal seagrasses show high variability in their extent and location, with local extinctions and (re-)colonizations being inherent in their population dynamics. Suitable habitats are identified usually using Species Distribution Models (SDM), based upon the overall distribution of the species; thus, accounting solely for spatial variability. To include temporal effects caused by large interannual variability, we constructed SDMs for different combinations and fusions of yearly distribution data. The main objectives were to: (i) assess the spatio-temporal dynamics of an intertidal seagrass bed of Zostera marina; (ii) select the most accurate SDM techniques to model different temporal distribution data subsets of the species; (iii) assess the relative importance of the environmental variables for each data subset; and (iv) evaluate the accuracy of the models to predict species conservation areas, addressing implications for management. To address these objectives, a time series of 14-year distribution data of Zostera marina in the Ems estuary (The Netherlands) was used to build different data subsets: (1) total presence area; (2) a conservative estimate of the total presence area, defined as the area which had been occupied during at least 4years; (3) core area, defined as the area which had been occupied during at least 2/3 of the total period; and (4–6) three random selections of monitoring years. On average, colonized and disappeared areas of the species in the Ems estuary showed remarkably similar transition probabilities of 12.7% and 12.9%, respectively. SDMs based upon machine-learning methods (Boosted Regression Trees and Random Forest) outperformed regression-based methods. Current velocity and wave exposure were the most important variables predicting the species presence for widely distributed data. Depth and sea floor slope were relevant to predict conservative presence area and core area. It is concluded that, the fusion of the spatial distribution data from four monitoring years could be enough to establish an accurate habitat suitability model of Zostera marina in the Ems estuary. The methodology presented offers a promising tool for selecting realistic conservation areas for those species that show high population dynamics, such as many estuarine and coastal species. [Copyright &y& Elsevier]

Abstract: The bathymetric LiDAR system is an airborne laser that detects sea bottom at high vertical and horizontal resolutions in shallow coastal waters. This study assesses the capabilities of the airborne bathymetric LiDAR sensor (Hawk Eye system) for coastal habitat mapping in the Oka estuary (within the Biosphere Reserve of Urdaibai, SE Bay of Biscay, northern Spain), where water conditions are moderately turbid. Three specific objectives were addressed: 1) to assess the data quality of the Hawk Eye LiDAR, both for terrestrial and subtidal zones, in terms of height measurement density, coverage, and vertical accuracy; 2) to compare bathymetric LiDAR with a ship-borne multibeam echosounder (MBES) for different bottom types and depth ranges; and 3) to test the discrimination potential of LiDAR height and reflectance information, together with multi-spectral imagery (three visible and near infrared bands), for the classification of 22 salt marsh and rocky shore habitats, covering supralittoral, intertidal and subtidal zones. The bathymetric LiDAR Hawk Eye data enabled the generation of a digital elevation model (DEM) of the Oka estuary, at 2 m of horizontal spatial resolution in the terrestrial zone (with a vertical accuracy of 0.15 m) and at 4 m within the subtidal, extending a water depth of 21 m. Data gaps occurred in 14.4% of the area surveyed with the LiDAR (13.69 km2). Comparison of the LiDAR system and the MBES showed no significant mean difference in depth. However, the Root Mean Square error of the former was high (0.84 m), especially concentrated upon rocky (0.55–1.77 m) rather than in sediment bottoms (0.38–0.62 m). The potential of LiDAR topographic variables and reflectance alone for discriminating 15 intertidal and submerged habitats was low (with overall classification accuracy between 52.4 and 65.4%). In particular, reflectance retrieved for this case study has been found to be not particularly useful for classification purposes. The combination of the LiDAR-based DEM and derived topographical features with the near infrared and visible bands has permitted the mapping of 22 supralittoral, intertidal and subtidal habitats of the Oka estuary, with high overall classification accuracies of between 84.5% and 92.1%, using the maximum likelihood algorithm. The airborne bathymetric Hawk Eye LiDAR, although somewhat limited by water turbidity and wave breaking, provides unique height information obscured from topographic LiDAR and acoustic systems, together with an improvement of the habitat mapping reliability in the complex and dynamic coastal fringe. [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]

Abstract: This contribution focuses upon the use of phytoplankton as an indicator of ecological quality in the coastal waters of the Basque Country (Bay of Biscay, northern Spain). The Water Framework Directive (WFD) establishes a common water policy in the European Union. The phytoplankton, owing to its relationship with the eutrophication processes, is one of the biological elements considered within the WFD. Phytoplankton biomass, composition and abundance, together with frequency and intensity of blooms, are the metrics to be assessed according to the WFD. In this work, data on phytoplankton biomass and frequency and intensity of blooms along the Basque coast were analysed. Phytoplankton biomass was evaluated using the 90th percentile of the chlorophyll-a concentrations (Chl-a) over a 6-year period (2001–2006). For the evaluation of the frequency of blooms, data on composition and abundance of the phytoplankton communities were obtained, then analysed using three different approaches. The first approach involved the utilisation of only some of the taxonomic groups (diatoms and dinoflagellates). The second approach divided the phytoplankton community into two size categories (>20 µm and 2–20 µm, cell diameter). The third approach used all of the phytoplankton taxa recorded in the sample. Evidence for the oligotrophy of the coastal waters of the Basque Country was provided by the low values obtained for the 90th percentile of the Chl-a (<3 µg L−1). Low intensity of upwelling activity, relatively small river loads and a narrow shelf characterise this coast, which can explain the low level of phytoplankton biomass. However, phytoplankton counts were relatively high compared with other neighbouring coastal waters a priori of higher trophic richness. These differences are discussed in relation to the methodologies for the analysis of cell counts which different monitoring programmes utilise in the European Union. [Copyright &y& Elsevier]

The study of the presence in the aquatic environment of certain substances considered as contaminants of emerging concern (CEC) is a preliminary step to the analysis of the possible harmful effects on aquatic ecosystems and the establishment of the corresponding environmental quality standards. In order to monitor the occurrence of CECs in the aquatic environment, the European Commission established in 2015 and 2018 two watch-list of substances for Union-wide monitoring in the field of water policy (Decision (EU) 2015/495 and Decision (EU) 2018/840). In the coast of the Basque Country, southeast of the Bay of Biscay, 19 of these watch list substances were monitored quarterly from May 2017 to March 2019. Water samples were collected at the effluent of three wastewater treatment plants and five control points associated with receiving waters (transitional and coastal water bodies). The most frequently quantified substances were azithromycin (91%), imidacloprid (82%), clarithromycin (80%), diclofenac (78%) and erythromycin (73%), with frequencies of quantification higher in wastewaters (83–100%) than in receiving waters (70–85%). In general, concentrations in wastewater were also higher than in receiving waters, indicating a dilution effect in the environment. In receiving waters, six out of the nineteen substances monitored exceeded their respective Predicted No-Effect Concentrations: azithromycin (34%), imidacloprid (9%), 17β-estradiol (E2) (9%), clarithromycin (7%), ciprofloxacin (7%), and diclofenac (5%); and therefore, their levels could pose an environmental risk. Unlabelled Image • The most frequently quantified substance was azithromycin. • In 34% of the receiving water samples, azithromycin presented high risk. • E1, E2, EHMC, thiacloprid and oxadiazon showed maximum values in receiving waters. • The information here can serve for more efficient monitoring of these substances. [ABSTRACT FROM AUTHOR]

Marine ecosystems provide many ecosystem goods and services. However, these ecosystems and the benefits they create for humans are subject to competing uses and increasing pressures. As a consequence of the increasing threats to the marine environment, several regulations require applying an ecosystem-based approach for managing the marine environment. Within the Mediterranean Sea, in 2008, the Contracting Parties of the Mediterranean Action Plan decided to progressively apply the Ecosystem Approach (EcAp) with the objective of achieving Good Environmental Status (GES) for 2018. To assess the environmental status, the EcAp proposes 11 Ecological Objectives, each of which requires a set of relevant indicators to be integrated. Progress towards the EcAp entails a gradual and important challenge for North African countries, and efforts have to be initiated to propose and discuss methods. Accordingly, to enhance the capacity of North African countries to implement EcAp and particularly to propose and discuss indicators and methods to assess GES, the aim of this manuscript is to identify the practical problems and gaps found at each stage of the environmental status assessment process. For this purpose, a stepwise method has been proposed to assess the environmental status using Ecologic Objective 5-Eutrophication as example.