Northwest Coast Of Portugal Research Articles

Fighting drift sands with pine trees: Reforestation of coastal areas of NW Portugal at the end of eighteenth century

From the late Middle Ages until the end of the nineteenth century, the northwest coast of Portugal was severely affected by drift sands, which led to the disappearance of villages or forced the population to migrate or suffer several losses. Along the northern European Atlantic coast, the most effective response to the drift sands was the reforestation of coastal areas, starting from the end of the eighteenth century and in the nineteenth century. In the northwest coast of Portugal, until the end of the nineteenth century, coastal planning and management was mainly the responsibility of local civil, manorial, and religious institutions. Based on historical sources, monastic institutions' forest management actions will be analyzed, and whether these initiatives successfully made communities in north-western Portugal less vulnerable to drift sands. This study will also allow a comparison of how the coastal landscape in the Portuguese Northwest has been reshaped and managed over two centuries, the profound impacts caused by tourism activities in the second half of the twentieth century, and the implementation of coastal management plans by the Portuguese State from 1993 onwards.

Assessing the Future wind Energy Potential in Portugal Using a CMIP6 Model Ensemble and WRF High-Resolution Simulations

Future wind energy potential over Portugal is assessed, using wind speed data from a WRF regional simulation under the SSP5-8.5 scenario for 2046–2065 and 2081–2100. Data from a CMIP6 multi-model ensemble were also used to assess future changes in the Euro-Atlantic large-scale circulation. CMIP6 results have shown a southward displacement of the mid-latitude jet stream during winter, and a northward displacement during spring, summer, and autumn, which causes the northern winds to strengthen during summer along the north-western Iberian coast. Furthermore, in 2046–2065 the wind power density (WPD) should increase between 25% and 50% off the northwest coast of Portugal and in the Serra da Estrela mountain range during summer, which is in agreement with the CMIP6 global ensemble projections. Analyses of WPD’s 2046–2065 daily variability of offshore north-western Portugal reveal a variability increase during winter, spring and summer, as well as more intense extreme WPD events, and less intense extreme events during autumn. The WPD’s 2046–2065 inter-annual variability should increase off the northwest coast, and decrease along the central western and southern coasts, whereas it should increase in the entire studied area in 2081–2100, apart from the northern mountain regions and Cape Raso.

Coastal Floods Induced by Mean Sea Level Rise—Ecological and Socioeconomic Impacts on a Mesotidal Lagoon

Coastal floods are currently a strong threat to socioeconomic activities established on the margins of lagoons and estuaries, as well as to their ecological equilibrium, a situation that is expected to become even more worrying in the future in a climate change context. The Ria de Aveiro lagoon, located on the northwest coast of Portugal, is not an exception to these threats, especially considering the low topography of its margins which has led to several flood events in the past. The growing concerns with these regions stem from the mean sea level (MSL) rise induced by climate changes as well as the amplification of the impacts of storm surge events, which are predicted to increase in the future due to higher mean sea levels. Therefore, this study aims to evaluate the influence of MSL rise on the inundation of Ria de Aveiro habitats and to assess the changes in inundation patterns resulting from frequent storm surges (2-year return period) from the present to the future, assessing their ecological and socioeconomic impacts. For this, a numerical model (Delft3D), previously calibrated and validated, was used to simulate the lagoon hydrodynamics under different scenarios combining MSL rise and frequent storm surge events. The numerical results demonstrated that MSL rise can change the vertical zonation and threaten the local habitats. Many areas of the lagoon may change from supratidal/intertidal to intertidal/subtidal, with relevant consequences for local species. The increase in MSL expected for the end of the century could make the lagoon more vulnerable to the effect of frequent storm surges, harming mostly agricultural areas, causing great losses for this sector and for many communities who depend on it. These extreme events can also affect artificialized areas and, in some cases, endanger lives.

Prevalence of phylogenetic over environmental drivers on the fatty acid profiles of the adductor muscle of marine bivalves and its relevance for traceability

Marine bivalves are among the most traded seafood worldwide. Along with their economic value, they are also an excellent source of proteins, vitamins, minerals, omega-3 and omega-6 fatty acids (FA). The FA profiles of the adductor muscle (AM) of bivalves can be successfully used to trace their geographic origin. This approach is paramount for traceability, as it allows to expose fraudulent practices associated with the capture of bivalves from unsuitable areas for human consumption that may put food safety at risk. However, it is yet to be determined whether phylogenetic or environmental drivers prevail on the shaping of FA signatures when comparing multiple bivalve species originating from the same location or distinct geographic origins. In this study, the FA profiles of the AM of six commercially important bivalve species (Cerastoderme edule, Crassostrea gigas, Mytilus galloprovincialis, Ruditapes philippinarum, Scrobicularia plana and Solen marginatus) from Ria de Aveiro (Northwest Coast of Portugal) were compared. Furthermore, the FA profiles of the AM of C. edule and R. phillipinarum originating from Ria de Aveiro and the Tagus estuary (~250 Km apart) were also compared to identify if phylogenetic drivers prevailed over environmental ones. The FA profiles of the AM of the six bivalve species sampled in Ria de Aveiro differed significantly among themselves, displaying higher levels of similarity between species belonging to the same infraclass. The comparison of species from the same ecosystem and specimens from different ecosystems evidenced that phylogenetic drivers prevail over environmental ones on the shaping of FA profiles of the AM. These findings are important for food safety issues, as they revealed that the FA profile of the AM of a given bivalve species cannot be used as a reliable proxy for another one when aiming to trace geographic origin. The transfer of this technology to bivalve’s production ensures product’s safety, promotion and differentiation, as well as a tool against fraud.

Function of estuaries and coastal areas as nursery grounds for marine fish early life stages

The present study describes the larval and juvenile fish fauna of an estuary and its adjacent coastal area (Mondego estuary, Northwest coast of Portugal) and evaluates their function as nurseries for marine fish. For this, larvae and juveniles were sampled in both systems. The temporal and spatial patterns of the ichthyoplankton community were described for each system and related to the influence of environmental factors. Additionally, the recruitment pattern was evaluated based on the composition of juveniles. Results show a seasonal variation of larval density and community structure between and within systems, indicating a degree of segregation according to their ecological functional classification. Temperature was the most important environmental factor structuring the communities. The juvenile recruitment patterns observed show a different nursery function of the estuary and coastal area for early life stages of different species, reinforcing the need to integrate larval and juvenile stages to better understand fish life cycles and the connectivity between systems.

Sea urchin grazing preferences on native and non-native macroalgae

Abstract Herbivory plays a major role in shaping community dynamics across freshwater, marine and terrestrial habitats, by controlling patterns of abundance and distribution of primary producers, including seaweeds. In the context of biological invasions, the proliferation of non-native seaweeds has been often attributed to limited grazing by native herbivores on introduced species (“Enemy Release Hypothesis”, ERH). In our study, we aimed to explore the potential of an abundant generalist herbivore (the sea urchin Paracentrotus lividus) to graze on non-native in comparison to native macroalgae species. For this purpose, we used manipulative experiments to assess sea urchin preference on native and non-native seaweed species present in the northwest coast of Portugal. Specifically, we determined the preferences of P. lividus on brown seaweeds i.e. Laminaria ochroleuca, Saccorhiza polyschides and the non-native Undaria pinnatifida, and red seaweeds i.e. Chondrus crispus, Mastocarpus stellatus and the non-native Grateloupia turuturu. For each group of seaweed species, sea urchin preference and biomass consumption were examined. The nutritional (organic carbon and nitrogen) and chemical (phenolic content) features were also analysed, in order to assess their effect on sea urchin feeding. According to the results, P. lividus did not show a specific preference for any of the different seaweeds of each phylum. These results suggest that P. lividus is a generalist herbivore, not exerting a differential grazing pressure on non-native seaweeds when compared to native ones.

Monitoring the evolution of nearshore nourishments along Barra-Vagueira coastal stretch, Portugal

Maintenance of existing harbors implies regular dredging activities. Where the combined use of dredging and disposal of dredged material on nearby sediment-starved beaches can induce major changes in the beach morphology and generate unexpected impacts in the environment, monitoring becomes a concern. This paper was designed to analyze, interpret and evaluate a set of monitoring data collected along a regular-nourished coastal stretch with dredged sand (Barra-Vagueira coastal stretch, northwest coast of Portugal), surrounded by an energetic hydrodynamic environment with a scarce natural sediment input. Based on a field data set, collected between 2009 and 2015, the present study brings together a set of correlated analyses, intended to assess the morphodynamic evolution of the fills as well as their impact to the adjacent coast. The available data set encompasses topo-hydrographic surveys collected for 12 cross-sections (with 1 km spacing) distributed along the coastal stretch and bathymetric measurements collected for the dumping areas. Considering the concurrent offshore wave forcing, dominant temporal and spatial patterns, morphological changes, evolution trends, sediment budgets, and short- and medium-term responses of the fills are investigated by the use of ArcGIS tools and application of a multivariate statistical method based on Empirical Orthogonal Functions (EOFs). Overall, during the monitoring period, almost 2.8 Mm3 of sand was dumped in different locations and periods to control the erosion observed downdrift of the inlet. However, bathymetric surveys and profile indicators still point out the erosional longshore pattern diagnosed decades ago as a result of a negative longshore sediment balance. Observations also revealed that short-term changes arising from the seasonal cycles of cross-shore material exchange are mainly linked to the largest variations in the beach profile shape, also affecting the sediment budget. Profiling indicated cross-shore volume variations ranging from ±250 m3/m and ±1500 m3/m in the subaerial and subaqueous portion of the profile, respectively, along the monitored period. After the first completed seasonal cycle the sand bar, artificially created by the nourishments, could not be visually detected in the profiles, suggesting a cross-shore redistribution of the fill material. All the analyses developed in this paper stress the importance of establishing proper monitoring programs based on adequate surveying instruments and data collection strategies, in order to ensure high-density data that could be used in support to the decision-markers.

Semi-automatic surface sediment sampling system – A prototype to be implemented in bivalve fishing surveys

In the current work we propose a new method to sample surface sediment during bivalve fishing surveys. Fishing institutes all around the word carry out regular surveys with the aim of monitoring the stocks of commercial species. These surveys comprise often more than one hundred of sampling stations and cover large geographical areas. Although superficial sediment grain sizes are among the main drivers of benthic communities and provide crucial information for studies on coastal dynamics, overall there is a strong lack of this type of data,possibly, because traditional surface sediment sampling methods use grabs, that require considerable time and effort to be carried out on regular basis or on large areas. In face of these aspects, we developed an easy and un-expensive method to sample superficial sediments, during bivalve fisheries monitoring surveys, without increasing survey time or human resources. The method was successfully evaluated and validated during a typical bivalve survey carried out on the Northwest coast of Portugal, confirming that it had any interference with the survey objectives. Furthermore, the method was validated by collecting samples using a traditional Van Veen grabs (traditional method), which showed a similar grain size composition to the ones collected by the new method, on the same localities. We recommend that the procedure is implemented on regular bivalve fishing surveys, together with an image analysis system to analyse the collected samples. The new method will provide substantial quantity of data on surface sediment in coastal areas, using a non-expensive and efficient manner, with a high potential application in different fields of research.

Pollicipes pollicipes as a Biomonitor of PAHs Contamination in Seawaters of the Northwest Coast of Portugal

ABSTRACTSimple, fast, and economic solid phase microextration–gas chromatography–mass spectrometry (SPME–GC–MS) methods were validated for the determination of 8 United States Environmental Protection Agency priority polycyclic aromatic hydrocarbons (PAHs: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene) in coastal seawaters and soft tissues of goose barnacles Pollicipes pollicipes. Under the optimized conditions, the limits of detection ranged from 0.012 to 1.069 ng L−1 and 0.002 to 0.061 µg kg−1 (dry weight basis) for seawaters and soft tissues, respectively. Precision varied between 3.9% and 20.0% for seawaters and between 8.4% and 19.1% for soft tissues, which are acceptable repeatabilities for environmental analyses. Finally, the accuracy of the optimized conditions also showed suitable recoveries, varying between 81.5% and 105.5% in spiked seawater samples and between 88.0% and 103.4% in the standard reference material for organics in mussel tissues (NIST SRM 2977). These methods were applied to a monitoring program performed along the northwest coast of Portugal during four seasons in 2011 in order to assess the levels of these compounds present in coastal waters and in the tissues of goose barnacles, one food resource of high commercial value. The results showed that although the concentrations of PAHs in seawaters and P. pollicipes varied significantly along the coast and between seasons (p < 0.05), in general the concentrations in seawater can be classified as “Class II – Good/Natural Background Concentrations” during the four seasons of 2011. As for the concentrations of PAHs in P. pollicipes, they were positively correlated (p < 0.05) with their concentrations in seawater, indicating that P. pollicipes may be an adequate biomonitor species of PAHs availabilities along the coast of Portugal throughout the year.

The spatial and seasonal variation of trace metals in coastal seawater and soft tissue of Chthamalus montagui around the northwest coast of Portugal

Metal concentrations (Cd, Cr, Cu, Fe, Mn and Zn) were determined in seawaters and soft tissues of Chthamalus montagui from the northwest coast of Portugal during the four seasons of 2011. The main objectives of this work were to assess seasonal and spatial variations of metals in order to detect hot spots of contamination, to establish correlations between metals in coastal seawaters and C. montagui and to calculate metal bioaccumulation factors (BAFs) in each season. Metal concentrations in coastal seawaters ranged within Cd: 1.2–35 ng L-1; Cr: 15–87 ng L-1; Mn: 77–1763 ng L-1; Cu: 126–1819 ng L-1; Fe: 430–4048 ng L-1 and Zn: 2889–16867 ng L-1 and in C. montagui ranged for Cd: 0.39–1.98 mg kg-1; Cr: 0.45–3.13 mg kg-1; Cu: 0.93–5.70 mg kg-1; Mn: 2.2–20.4 mg kg-1; Fe: 135–707 mg kg-1 and Zn: 119–782 mg kg-1. Significant spatial and seasonal variations were found between: (i) metal concentrations in seawaters and C. montagui tissues; (ii) the distribution of metal concentrations in C. montagui tissues were Fe > Zn > Mn > Cu > Cr > Cd and (iii) C. montagui showed higher bioaccumulation factors for Fe and Cd than for Cu, Mn and Zn in all seasons. Regarding the metal concentrations accumulated in C. montagui tissues during each season of 2011, the ecological quality classifications of the NW coast of Portugal varied from “Class I–Unpolluted” to “Class III–Remarkably Polluted”.

A sensory and nutritional comparison of mussels (Mytilus sp.) produced in NW Iberia and in the Armona offshore production area (Algarve, Portugal)

A biometric, nutritional and sensory analysis of raw and cooked mussels comparing Mytilus sp. from the north-west coast of Portugal and Spain (Minho and Galicia, respectively) and the new offshore production site of Armona (Algarve, south Portugal) was carried out. In addition, multiple factorial analysis was performed to explore potential relationships between sensory attributes and nutritional content properties between the different mussels. Results showed that, at similar times of sale, biometrics of mussels from Armona and Vigo were similar and bigger than the remaining. Nonetheless, despite some similarities in proximate composition, mussels presented differences in lipid classes, fatty acid content and free amino acids profiles. These differences were not fully reflected in the sensory assessment by the panel, which were able to distinguish different production sites in raw specimens but displayed problems in discrimination these in cooked mussels. Some nutritional components were related to specific sensory sensations.

Fucus spiralis as monitoring tool of metal contamination in the northwest coast of Portugal under the European Water Framework Directives.

Metals (Cd, Cr, Cu, Fe, Mn and Zn) in coastal seawaters and soft tissues of macroalga Fucus spiralis from the northwest coast of Portugal were determined to assess spatial variations of metal bioavailabilities and bioaccumulation factors to compare different ecological quality classifications. Both coastal seawaters and soft tissues of F. spiralis showed significant spatial variations in their metal concentrations along the coast. The macroalgae F. spiralis accumulated more efficiently Cd, Mn and Zn and showed low bioaccumulation factors to Cr, Cu and Fe. Regarding the metal guidelines of the Norwegian Pollution Control Authority, the entire northwest (NW) coast of Portugal in April 2013 should be classified as 'class I--unpolluted' for all metals, except in Ave for Cu ('class II--moderately polluted') and Cavado for Cd and Cu ('class II-moderately polluted'), revealing the low metal bioavailabilities of these seawaters. As there were always significant positive correlations between all metals in seawaters and F. spiralis, this macroalga species was considered a suitable monitoring tool of metal contamination in the NW coast of Portugal and a useful aquatic organism to be included in the European Environmental Specimen Banks in order to establish a real-time environmental monitoring network under the European Water Framework Directives.

Seasonal variation of metal contamination in the barnacles Pollicipes pollicipes in northwest coast of Portugal show clear correlation with levels in the surrounding water

The concentrations of metals were determined in northwest (NW) coast of Portugal seawaters and soft tissues of goose barnacles Pollicipes pollicipes. P. pollicipes can be used for monitoring metal contamination in these coastal seawaters, because there were significant correlations (p<0.05) for all metals between soft tissues and seawaters during the four seasons. Metal concentrations in seawaters and P. pollicipes had significant (p<0.05) spatial and seasonal variations and mean log BAFs for Fe and Cd were higher than for Cr, Cu, Mn and Zn. Regarding the metal concentrations obtained in the coastal seawaters, all NW coast of Portugal should be classified as “Class IV – Bad”, except two locations (location 7 at Summer and location 10 at Winter), which should be classified as “Class III – Moderate”. However, considering the metal concentrations bioaccumulated in P. pollicipes, all locations should be classified as “Class III – Remarkably Polluted” during all seasons of 2011.

Numerical modelling of shoreline evolution in the Aveiro coast, Portugal – climate change scenarios

ABSTRACT Pereira, C., Coelho, C., Ribeiro, A., Fortunato, A., Lopes, C.L. and Dias, J.M., 2013. Numerical modelling of shoreline evolution in the Aveiro coast, Portugal – climate change scenarios In the Northwest coast of Portugal, the shoreline evolution is leading to several problems, such as loss of territory and infrastructural damages, mainly caused by the sea wave's action. This study aims to predict the impacts of climate change on the shoreline evolution in this coastal area. Coastal stretches studied were Esmoriz-Furadouro and Vagueira-Mira, due to their vulnerability related with the low lying sandy coast, the deficit of sediments, the presence of urban waterfronts and the narrow width of the sand spit that separates the ocean from the Aveiro lagoon. The paper describes the application of two shoreline evolution models (LTC and GENESIS) to the projection of shoreline evolution between 2010 and 2100. A reference scenario considering the present typical wave climate and the mean sea water level wa...

Northwest Coast of Portugal – Past behavior and future coastal defense options

ABSTRACT Costa, S. and Coelho, C., 2013. Northwest coast of Portugal Past – behavior and future coastal defense options Portugal's northwest coast, between Ovar and Marinha Grande presents an important sediment deficit, mainly due to rivers sediments supply reduction and harbors' constrains. The sediment transport capacity resulting from the wave's action (mainly from the northwest) is nourished with the sand of the up drift beaches, leading to the shoreline's erosion and retreat. The shoreline retreat represents conflicts with the land use and human occupation, and the protection of people and properties becomes essential. Thus, coastal interventions (seawalls and groins), try to constrain the shoreline evolution, conducting to an artificial coast and site aesthetical deterioration. This work's objective is to present an analysis of the shoreline evolution, in order to select a suitable model of coastal intervention. Thus, the current paper aimed a diagnostic based in the shoreline evolution indicators i...

Goose barnacle Pollicipes pollicipes as biomonitor of metal contamination in the northwest coast of Portugal

The main objective of this work was to assess the potential use of goose barnacle Pollicipes pollicipes as biomonitor of metal contamination in northwest (NW) coast of Portugal. The concentrations of Cd, Cr, Cu, Fe, Mn, Ni and Zn were determined in coastal seawaters and tissues of P. pollicipes, which allowed establishing correlations between metals in coastal seawaters and P. pollicipes and calculating metal bioaccumulation factors (BAFs). The results of this study showed that P. pollicipes soft tissues can be used for monitoring metal contamination in these coastal seawaters: (1) there were significant correlations (p < 0.05) between metals in soft tissues and their concentrations in seawaters, except for Zn (p > 0.05); (2) soft tissues were sensitive to spatial variations of metal bioavailabilities and their concentrations ranged 0.70-2.22 mg Cd kg(-1), 0.49-1.40 mg Cr kg(-1), 1.37-2.07 mg Ni kg(-1), 2.4-3.3 mg Cu kg(-1), 5-59 mg Mn kg(-1), 134-578 mg Fe kg(-1)and 728-1,854 mg Zn kg(-1); (3) mean logarithmic bioaccumulation factors (log BAF) of Fe, Cd and Zn were higher, 5.57, 5.47 and 4.41, respectively, than mean log BAFs of Cr, Mn, Cu and Ni, 4.18, 4.14, 3.98 and 3.51, respectively. In contrary, P. pollicipes shell plates were not considered ideal material to monitor metal bioavailabilities in these coastal seawaters. Regarding the very high concentrations of Zn obtained in the coastal seawaters and P. pollicipes soft tissues, the NW coast of Portugal should be classified as "Class III/IV - Remarkably/Highly Polluted".

Modelling of the coastal defence scheme of Espinho, Portugal

The most recent intervention on the coastline of Espinho, located on the Portuguese West Atlantic coast, was part of the General Plan for Coastal Protection in 1980/81. As a result, two unusually large groins/headlands were built which were reinforced and enlarged in 1997, slightly changing their geometry and orientation. However, due to the decreased sediment supply from the north and the impact of energetic sea conditions common to the northwest coast of Portugal the coastal evolution has not developed as desired, although in general terms the initial expectations were fulfilled. The numerical modelling of the Espinho coastline using SMC software focused on both hydrodynamic and hydromorphological aspects. The purpose of this study is to analyse the most vulnerable areas of the Espinho seafront for current velocities and littoral drift, as well as to confirm the effectiveness of the two groins in terms of coastal protection. To achieve this, various simulations were performed, taking into account diverse sea conditions.

Chthamalus montagui as biomonitor of metal contamination in the northwest coast of Portugal

The concentrations of seven metals (Cd, Cr, Cu, Fe, Mn, Ni and Zn) were determined in coastal seawaters and soft and hard tissues of the barnacle Chthamalus montagui from the northwest coast of Portugal to assess the potential use of C. montagui as biomonitor of metal contamination. The results of this study showed that C. montagui soft tissues can be used for monitoring metal bioavailabilities in these coastal seawaters: (1) there were significant correlations (p < 0.05) between the metal concentrations in soft tissues and their concentrations in seawaters and (2) barnacle soft tissues were sensitive to spatial variation of metal bioavailabilities, accumulating different amounts of metals in different locations. The range of concentrations in tissues were: 0.59-1.7 mg Cd kg(-1), 0.5-3.2 mg Cr kg(-1), 0.72-3.0 mg Ni kg(-1), 1.2-6.7 mg Cu kg(-1), 9-26 mg Mn kg(-1), 214-785 mg Fe kg(-1) and 178-956 mg Zn kg(-1); (3) mean logarithmic bioaccumulation factors (log BAF) of Fe, Cr and Cd were higher, 5.49, 4.93 and 4.46, respectively, than mean log BAFs of Mn, Zn, Cu and Ni, 4.03, 3.97, 3.74 and 3.61, respectively. In contrary, C. montagui shell plates were not a good matrix to monitor metal bioavailability in these coastal seawaters, with no significant correlations (p < 0.05) between metal concentrations in the shell and in seawater. Regarding the high Zn concentrations obtained in the coastal seawaters and C. montagui soft tissues, all seawaters from northwest coast of Portugal should be classified as "moderately/remarkably polluted".

Morphology, ultrastructure, genetics, and morphometrics of Diplostomum sp. (Digenea: Diplostomidae) metacercariae infecting the European flounder, Platichthys flesus (L.) (Teleostei: Pleuronectidae), off the northwest coast of Portugal

The morphology, ultrastructure, genetics, and morphometrics of a species of Diplostomum von Nordmann 1832 (Digenea: Diplostomidae), isolated from the European flounder (Platichthys flesus (L.)) caught off the northwest coast of Portugal, are characterized. The metacercarial stage was found unencysted in the lens capsule of the eye. Light microscopical observations revealed the existence of some variability in specimen shape and size, with two morphotypes, referred to as "round" and "long", being apparent. Scanning electron microscopy revealed a smooth, unarmed tegument, with the lappet region being the most irregular and porose. Both the oral and ventral suckers were provided with a series of papillae, which presented very distinctive ultrastructural features and were particularly conspicuous in the case of the ventral sucker. The two morphotypes detected were found to have 100% genetic correspondence in the 18S + ITS1 + 5.8S region of the rDNA. Since the genetic data for this metacercaria differed from those of the species of Diplostomum available in GenBank, a description of a new genotype (accession number GQ370809) is provided. The molecular phylogenetic analyses, in conjunction with principal components and cluster analyses based on morphometric data, revealed the existence of consistent differences between the Diplostomum sp. metacercariae from flounder compared with Diplostomum spathaceum, Diplostomum mergi, Diplostomum pseudospathaceum, and Diplostomum paracaudum. The latter of these species was found to be the most similar to the present material. Our results do not support an evolutionary separation of the European and North American species of Diplostomum.

Environmental isotopes (15N and 18O) in the assessment of groundwater degradation: Aveiro Quaternary aquifer (NW Portugal)

The Aveiro region, situated on the Northwest coast of Portugal is one of the most industrialized areas of Portugal. The shallow Quaternary aquifer system, mainly of detrital sediments of Pleistocene and Holocene ages, is still today an important water resource for this region despite growing evidence of diffuse pollution problems. Isotope techniques have been used to evaluate the aquifer vulnerability to nitrate contamination (δ18O and δ15N from NO3 and δ2H and δ18O from H2O). Nitrogen isotopes were used to identify nitrogen sources and assess agriculture, cattle-breeding, urban and industrial contributions to the nitrogen cycle in the Aveiro ecosystem.