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Abstract Fish age and growth data are crucial for understanding vital species’ traits and their populations. Boarfish is a pelagic species widely distributed in the Northeast Atlantic that is one of the most discarded non-commercial species on the Portuguese coast. Due to its potential valorisation as a new fishery in the Northeast Atlantic, boarfish has become object of interest in several published studies. However, since no age standard protocol has been implemented for boarfish, studies have used a variety of different otolith preparation techniques to estimate age, leading to contradicting and discrepant results. This research aims to consolidate biological insights into boarfish age and growth, lay the foundation for a standardized ageing protocol and serve as a benchmark study for the Portuguese west coast before commercial exploitation. Through the comparison of two otolith ageing methodologies, this study recommends using whole otoliths as the best method, revealing a maximum age of 15 years. The growth pattern estimated, indicated a biphasic growth pattern, with a faster initial growth rate that slows down at 2.4 years, the moment of change, when energy is allocated for sexual maturation. This finding was corroborated by a maturity ogive and analysis of fish size and otolith length relationship.

Fish age and growth data are crucial for understanding vital species' traits and their populations. Boarfish is a pelagic species widely distributed in the Northeast Atlantic that is one of the most discarded non-commercial species on the Portuguese coast. Due to its potential valorisation as a new fishery in the Northeast Atlantic, boarfish has become object of interest in several published studies. However, since no age standard protocol has been implemented for boarfish, studies have used a variety of different otolith preparation techniques to estimate age, leading to contradicting and discrepant results. This research aims to consolidate biological insights into boarfish age and growth, lay the foundation for a standardized ageing protocol and serve as a benchmark study for the Portuguese west coast before commercial exploitation. Through the comparison of two otolith ageing methodologies, this study recommends using whole otoliths as the best method, revealing a maximum age of 15 years. The growth pattern estimated, indicated a biphasic growth pattern, with a faster initial growth rate that slows down at 2.4 years, the moment of change, when energy is allocated for sexual maturation. This finding was corroborated by a maturity ogive and analysis of fish size and otolith length relationship. [ABSTRACT FROM AUTHOR]

The main objective of this study is to perform an approximation on the microplastic pollution on a sandy beach in Costa Nova (Portugal), focused on longitudinal and cross-sectional transects. The results showed a scarce variability in data, with median concentrations ranging from 142 to 356 p/kg d.w. and 211 to 270 p/kg d.w. in cross-sectional and longitudinal transects, respectively. The predominant morphology was microspheres, which accounted for more than 90% in all samples analysed, whereas the most abundant microplastics were <200 µm in size. Microplastic contamination was higher than in other Portuguese beaches despite the moderate–low touristic pressure in Costa Nova, which led us to consider the intense commercial activity of the nearby port and the Canary and Portuguese currents as possible drivers of microplastic pollution in this area. However, this study highlights the disparity in data caused by different methodologies used when similar areas are analysed. [ABSTRACT FROM AUTHOR]

Bivalves are a high-value product whose production has markedly increased, reaching 9863 tonnes in Portugal in 2021. Bivalves' habitats—lagoons, estuaries and coastal waters—are exposed to biological and anthropogenic contaminants, which can bioaccumulate in these organisms and pose a significant public health risk. The need to obtain a safe product for human consumption led to the implementation of standardised hygiene regulations for harvesting and marketing bivalve molluscs, resulting in routine monitoring of bivalve production areas for microbial quality, metal contaminants, and marine biotoxins. While excessive levels of biotoxins and metal contamination lead to temporary harvesting bans, high faecal contamination leads to area reclassification and impose post-harvest treatments. In this study, the seasonal and temporal variability of these parameters were analysed using historical data generated by the monitoring programme during the last decade. Moreover, the impact of the monitoring program on bivalve harvesting from 2011 to 2020 was assessed. This program presented a considerable improvement over time, with an increase in the sampling effort and the overall program representativeness. Finally, contamination risk, revising control measures, and defining recommendations for risk mitigation measures are given in the light of ten years' monitoring. [ABSTRACT FROM AUTHOR]

Diarrhetic Shellfish Poisoning (DSP) is an acute intoxication caused by the consumption of contaminated shellfish, which is common in many regions of the world. To safeguard human health, most countries implement programs focused on the surveillance of toxic phytoplankton abundance and shellfish toxicity levels, an effort that can be complemented by a deeper understanding of the underlying phenomena. In this work, we identify patterns of seasonality in shellfish toxicity across the Portuguese coast and analyse time-lagged correlations between this toxicity and various potential risk factors. We extend the understanding of these relations through the introduction of temporal lags, allowing the analysis of time series at different points in time and the study of the predictive power of the tested variables. This study confirms previous findings about toxicity seasonality patterns on the Portuguese coast and provides further quantitative data about the relations between shellfish toxicity and geographical location, shellfish species, toxic phytoplankton abundances, and environmental conditions. Furthermore, multiple pairs of areas and shellfish species are identified as having correlations high enough to allow for a predictive analysis. These results represent the first step towards understanding the dynamics of DSP toxicity in Portuguese shellfish producing areas, such as temporal and spatial variability, and towards the development of a shellfish safety forecasting system. [ABSTRACT FROM AUTHOR]

Physico-chemical and biological parameters along the Portuguese coast were analyzed to evaluate the potential to produce aquatic species of economic interest. Water samples were collected in 2018 and 2019 in five different areas of the Portuguese coast. Currents data were collected between 2018 and 2020 and historical waves height data from 1988 to 2019. According to the results, there is a wide variety of species that can be considered for production. The northernmost area presented the lowest temperature, as well as the highest levels of chlorophyll a, and nitrate. Under such conditions, the rearing of salmon Salmo salar, mussel Mytilus edulis, scallop Pecten maximus, macroalgae Porphyra umbilicalis, and Undaria pinnatifida can be considered. Regarding the southernmost area, due to the highest temperature, this area seems appropriate for the production of meager Argyrosomus regius, sea bream Sparus aurata, sea bass Dicentrarchus labrax, and greater amberjack Seriola dumerili. This study highlights the challenges in deploying aquaculture structures on the Atlantic coast due to its oceanographic conditions. Site selection for aquaculture is a complex process and pilot studies are essential to analyze the feasibility of developing offshore aquaculture along the coast of Portugal. [ABSTRACT FROM AUTHOR]

Physico-chemical and biological parameters along the Portuguese coast were analyzed to evaluate the potential to produce aquatic species of economic interest. Water samples were collected in 2018 and 2019 in five different areas of the Portuguese coast. Currents data were collected between 2018 and 2020 and historical waves height data from 1988 to 2019. According to the results, there is a wide variety of species that can be considered for production. The northernmost area presented the lowest temperature, as well as the highest levels of chlorophyll a, and nitrate. Under such conditions, the rearing of salmon Salmo salar, mussel Mytilus edulis, scallop Pecten maximus, macroalgae Porphyra umbilicalis, and Undaria pinnatifida can be considered. Regarding the southernmost area, due to the highest temperature, this area seems appropriate for the production of meager Argyrosomus regius, sea bream Sparus aurata, sea bass Dicentrarchus labrax, and greater amberjack Seriola dumerili. This study highlights the challenges in deploying aquaculture structures on the Atlantic coast due to its oceanographic conditions. Site selection for aquaculture is a complex process and pilot studies are essential to analyze the feasibility of developing offshore aquaculture along the coast of Portugal.

In a period when the Iberian sardine stock abundance is at its historical minimum, knowledge of the sardine juvenile’s distribution is crucial for the development of fishery management strategies. Generalized additive models were used to relate juvenile sardine presence with geographical variables and spawning grounds (egg abundance) and to model juvenile abundance with the concurrent environmental conditions. Three core areas of juvenile distribution were identified: the Northern Portuguese shelf (centred off Aveiro), the coastal region in the vicinity of the Tagus estuary, and the eastern Gulf of Cadiz. Spatial differences in the relationship between juvenile presence and egg abundances suggest that essential juvenile habitat might partially differ from the prevailing spawning grounds. Models also depicted significant relationships between juvenile abundance, temperature and geographical variables in combination with salinity in the west and with zooplankton in the south. Results indicate that the sardine juvenile distribution along the Iberian Peninsula waters are an outcome of a combination of dynamic processes occurring early in life, such as egg and larva retention, reduced mortality and favourable feeding grounds for both larvae and juveniles.

Anisakiasis is a problematic zoonotic infection associated with the consumption of raw or undercooked fish. Atlantic mackerel (Scomber colias) is of high commercial interest in Portugal and has been reported as a common host of Anisakisspp. In this study, the occurrence of anisakids is evaluated in S. colias and also Scomber scombrus, and the potential zoonotic risk associated with consumption of these two fishes is evaluated according to the recorded infection levels. These were found to be high for both fish species: a mean intensity and prevalence of 21.7 worms/fish and 85% for S. colias, and 16.4 worms/fish and 83.3% for S. scombrus, respectively. No correlation was detected between anisakid intensity and host total length, total weight, condition factor, and hepatosomatic and gonadosomatic indices for both fish species, but significantly higher intensity values were detected for more mature S. scombrus, i.e. fish recording a higher gonadosomatic index. Molecular tools allowed the identification of two species of Anisakis, A. simplex (s.s.) and A. pegreffii. They differed in their occurrence: in S. colias the prevalence of A. simplex (s.s.) was 18% and that of A. pegreffii was 82%, whereas in S. scombrus the prevalence of A. simplex (s.s.) was 73% and that of A. pegreffii was 27%. Occasionally, worms of Hysterothylacium aduncum were identified for both fish. The different infection levels of the two Anisakisspecies in both hosts off the Portuguese coast raise the hypothesis of a different life cycle at the level of the invertebrate intermediate host. S. colias lives in deeper waters than S. scombrus, and the differences found in infection levels suggest that A. pegreffii main first intermediate host also live in deeper waters, compared with A. simplex (s.s.) main first intermediate host. The higher infection levels of A. simplex (s.s.) (most infectious to humans) in S. scombrus suggest that its consumption when slightly cooked, as in grilled fish (so popular in Portugal), could be more problematic for the development of anisakiasis in humans than the consumption of S. colias and thus be of potential public health concern.

Some pouting caught off the Atlantic coast of Portugal are discarded as unmarketable due to a dark discolouration of the skin and muscle. This study investigates the cause of this condition, describes the new parasite species responsible, and highlights the importance of educating those in charge of premarket inspection of food fish in order to reduce likelihood that consumers will eat infected fish. Macroscopically, infected fish showed considerable heterogeneity in darkening of the skin and hypaxial and epaxial muscles. Microscopical observation revealed bipolar nematode eggs in varying stages of development arranged in a linear pattern along muscle fibers. Histopathology confirmed the presence of eggs of a nematode of the genus Huffmanela Moravec, 1987 as the cause of muscle darkening and established a relationship between infection intensity and consequent darkened appearance of the tissues. The eggs are oval or barrel-shaped, with a smooth surface and polar plugs at opposite ends. The thin outer vitelline membrane is smooth and lacks ornamentation. Under light microscopy, the main eggshell of older eggs exhibits the outermost delicate and smooth vitelline membrane, and a thicker layer, correspondent to chitinous and chondroitin proteoglycan layers. Scanning electron microscopy of eggs confirmed light microscopic studies, namely the presence of a smooth vitelline membrane surrounding the egg. Microscopic and ultrastructural characteristics of eggs, and a new host family in a new geographic area, all suggest that a new species, herein named Huffmanela lusitana sp. n. is involved. Image 1 • Huffmanela lusitana sp. n in Trisopterus luscus. • Dark muscle due to Huffmanela eggs. • H. lusitana sp. n as the cause of disgusting aspect of infected fish meat. • H. lusitana sp. n as a zoonotical potential infection to consumers. • H. lusitana sp. n. as a constraint factor of healthy wildlife stocks. [ABSTRACT FROM AUTHOR]

• Temperature thresholds restrict O. cf. ovata distribution range in Iberia. • Lisbon Bay is the current W Iberian northern distribution limit of O. cf. siamensis. • Positive SST anomalies favor the occurrence of Ostreopsis spp. in Lagos Bay. • Low sea state favor the occurrence of Ostreopsis spp. in Lagos Bay. The benthic genus Ostreopsis contains toxic-bloom forming species and is an important cause of concern in warm-temperate and tropical waters. On the coast of Portugal, NE Atlantic, the occurrence of Ostreopsis cf. siamensis and Ostreopsis cf. ovata has been reported since 2008 and 2011, respectively. This work aims to understand the favorable conditions for high concentrations of Ostreopsis cells in the plankton at two sites, Lagos and Lisbon Bays, located in the South and West coast of Portugal, respectively. This study is based on weekly Ostreopsis abundance data in the plankton, from 2011 to 2017, daily satellite and in situ sea surface temperature (SST), and meteorological and sea state parameters, namely wind stress and significant wave height. The molecular identification of local Ostreopsis spp. is also presented. The maximum cell densities occur between late-summer and autumn. The distribution range of Ostreopsis cf. ovata is restricted to the South coast, while Ostreopsis cf. siamensis has a wider distribution range, being also present on the West coast. In the study period, there was only one occurrence of Ostreopsis spp., in Lagos Bay, with concentrations within the alert phase of monitoring. In Lagos Bay, high Ostreopsis spp. concentrations were related with positive SST anomalies. These high concentrations were often recorded after a period of almost 2-weeks to more than 4-weeks of low sea state (<0.6 m), followed by short time events of onshore wind and moderate waves (0.6–1 m). The former conditions are interpreted as favoring bloom development on the substrate and the latter as causing the re-suspension of Ostreopsis cells in the water column. In Lisbon Bay, O. cf. siamensis occurred in the plankton in few occasions and no clear relation could be established with the studied environmental variables. It is here hypothesized that the recent records of O. cf. siamensis in Lisbon Bay may correspond to an early colonization stage of an invasion process. Knowledge gained on Ostreopsis dynamics along the Portuguese coast can be used for both the improvement of benthic harmful algal blooms (BHABs) monitoring in the region and as a basis to design forecasting models. [ABSTRACT FROM AUTHOR]

This work provides for the first time a description of the reproductive biology of Trachurus picturatus in Portuguese continental waters (between 41° 49′ and 36° 57′ latitude North). From January 2010 to December 2016 a total of 7409 individuals were sampled from bottom trawlers operating on the northwestern coast of Portugal. The observed sex ratio was 0.56 in favor of the females. Monthly variations in gonadosomatic index, proportion of actively spawning individuals, hepatosomatic index and Fulton′s condition factor were analyzed. More than 60% of spawning individuals were recorded in the first quarter, corresponding to the highest values of GSI, and Fulton's K and hepatosomatic index increased after the start of spawning. The morphometric relationships between total length and gutted weight showed significant correlations (high determination coefficient, r2 > 0.9) and isometric growth (b = 3) for both sexes. Results indicate that the spawning season of T. picturatus starts in December and extends until April–May, with a peak in March, which agrees with what has been indicated by other authors for the northeast Atlantic. This work provides important biological information on a species that although not subject to stock assessment is currently the 5th species landed by weight in Portuguese continental waters. [ABSTRACT FROM AUTHOR]

Abstract Innate immune status of the sea urchin Paracentrotus lividus population from two different rocky shore beaches in the northern Portuguese coast was evaluated for a period of one year. Although some ecological studies regarding the effect of toxics on the immune parameters of the sea urchin were made in Portuguese waters, there is a current lack of knowledge concerning their immune status all over the year. In perspective of a changing ecosystem in these waters due to global warming and colonization of new species, it is important to assess the status of the major species living in the area. In this way, immune parameters such as total protein content, nitric oxide concentration, haemolytic activity, protease activity, lysozyme concentration and bactericidal activity were evaluated in the perivisceral coelomic fluid, and were correlated with the gonadal index of the population and water parameters. Also, the spawning period can upset some immune status parameters, and others such as haemolytic activity and bactericidal activity against Vibrio anguillarum, showed a clear correlation with the gonad maturation status. The knowledge of the basal immune status of the species could serve as ecological indicator of some stress agent or contaminant into the field; also, coelomic fluid is suggested as good quality marker to assess the immune status of sea urchins. Highlights • Annual survey of the humoral innate system of Paracentrotus lividus. • Decrease of innate immune parameters due to spawning period. • Positive correlation of haemolytic activity and bactericidal activity with gonad maturation. • Small differences recorded between sampling sites; good status of the northern Portuguese coast population. • Perivisceral coelomic fluid suggested as a good quality marker for assessing health of sea urchins. [ABSTRACT FROM AUTHOR]

The consequences of reallocating fishing effort from trawling to creels in an area off the West coast of Portugal for the operation of the trawl fleet, as well as on the population dynamics and the global catch value for a high-valued species, the Norway lobster ( Nephrops norvegicus ) are evaluated. The results suggest that only small portions of the area of interest are used by the trawl fleet, opening the possibility for a trawl ban without major disruption of the trawling activity. Economic benefits are expected, since predictions two scenarios tested, heavy and moderate exploitation, indicate no loss of catch value with much lower operational costs. Social benefits to local communities can also be expected since a much lower investment is needed for creel fishing, making this fishery attractive to small local companies already operating in the region. The proposed ban is consistent with the ecosystem approach to fisheries management and the Common Fisheries Policy (CFP) where the transition towards more responsible fishing practices is encouraged. [ABSTRACT FROM AUTHOR]

Fonseca, R.B.; Gonçalves, M., and Guedes Soares, C., 2017. Comparing the performance of spectral wave model for coastal areas. In the present study, the third-generation spectral wave models MIKE 21 BW, SWAN, and STWAVE are compared for the simulation of wave characteristics in shallow waters. The SWAN and STWAVE results were obtained from a previous study that compared their performance. The MIKE 21 BW results are now obtained with the purpose of comparing them with the previous two. Several target areas in the Portuguese coast were considered: Obidos Bay and Figueira da Foz, both located in the central part of the continental Portuguese coast; Leixões Harbor, located in the north coast; and Sines Harbor, located in the west coast, south of Lisbon. The input parameters for the models were obtained from offshore buoys. In situ measurements from buoys and acoustic Doppler current profilers were used to validate the model outputs. The models' results are compared through the wave's parameters, namely the significant wave height ( Hs), peak period ( Tp), and mean wave direction (Dir). The sensitivity of MIKE 21 SW to some input parameters and physical processes such as wind, tide, and nonlinear interactions is also verified. Information about the model performance for different forcing conditions and area types (bay, port, and straight shoreline) is provided. The results show a similar behavior among the models and they are statistically comparable. Both MIKE 21 SW and SWAN are complex models and have a large set of formulations and parameter choices. On the other hand, despite its simplicity, STWAVE produced good results and is considerably faster than the other two. [ABSTRACT FROM AUTHOR]

Chlorophyll- a (Chl a ) is a key parameter for the assessment of water quality in coastal and shelf environments. The availability of satellite ocean colour offers the potential of monitoring these regions at unprecedented spatial and temporal scales, as long as a high level of accuracy can be achieved. To use satellite derived Chl a to monitor these environments, it is imperative that rigorous accuracy assessments are undertaken to select the most accurate ocean colour algorithm(s). To this end, the accuracy of a range of ocean colour Chl a algorithms for use with Medium Imaging Resolution Spectrometer (MERIS) Level 2 (L2) Remote Sensing Reflectance ( R rs ), using two different atmospheric correction (AC) processors (COASTCOLOUR and MERIS Ground Segment processor version 8.0 – MEGS8.0), were assessed in North West European waters. A total of 594 measurements of R rs (λ) and/or Chl a were made in the North Sea, Mediterranean Sea, along the Portuguese Coast, English Channel and Celtic Sea between June 2001 and March 2012, where Chl a varied from 0.2 to 35 mg m − 3 . The following algorithms were compared: MERIS Case 1 water Chl a algorithm OC4Me, the MERIS Case 2 algorithm Algal Pigment 2 (AP2), the MODIS-Aqua Case 1 Chl a algorithm OC3 adapted for MERIS (OC3Me), the MODIS-Aqua Garver-Siegel-Maritorena algorithm (GSM) adapted for MERIS and the Gohin et al. (2002) algorithm for MERIS (OC5Me). For both COASTCOLOUR and MEGS8.0 processors, OC5Me was the most accurate Chl a algorithm, which was within ~ 25% of in situ values in these coastal and shelf waters. The uncertainty in MEGS8.0 R rs (442) (~ 17%) was slightly higher compared to COASTCOLOUR (~ 12%) from 0.3 to 7 mg m − 3 Chl a , but for R rs (560) the uncertainty was lower for MEGS8.0 (~ 10%) compared to COASTCOLOUR (~ 13%), which meant that MEGS8.0 Chl a was more accurate than COASTCOLOUR for all of the Chl a algorithms tested. Compared to OC5Me, OC4Me tended to over-estimate Chl a , which was caused by non-algal SPM especially at values > 14 g m − 3 . GSM also over-estimated Chl a , which was caused by variations in absorption coefficient of coloured dissolved organic matter at 442 nm ( a CDOM (442)). AP2 consistently under-estimated Chl a , especially when non-algal SPM was > 4 g m − 3 . [ABSTRACT FROM AUTHOR]

Four flatfish species were collected between January 2003 and June 2005 from commercial fishing vessels operating with gill nets and bottom trawls along the Portuguese coast in order to examine feeding habits, age and growth and reproduction. Citharus linguatula (Linnaeus, 1758), Lepidorhombus boscii (Risso, 1810) and Microchirus azevia (de Brito Capello, 1867) fed mainly on crustaceans, whereas Platichthys flesus (Linnaeus, 1758) fed mainly on echinoderms and crustaceans. Feeding activity was highest in spring and summer; females and small individuals showed the lowest vacuity index values. For all the species, significant differences were found in the proportion of prey items according to season, sex and size class. M. azevia had the largest diet spectrum. Ages were determined from sagittal otoliths. The von Bertalanffy growth equation coefficients differed between sexes. The asymptotic length L∞ of females was higher than that of males, except in C. linguatula. The lowest growth coefficient was obtained for P. flesus (k=0.11 for males and k=0.10 for females) and M. azevia showed the highest growth coefficient estimates (k=0.40 for females and k=0.30 for males). The highest proportion of individuals at spawning stage was recorded in winter for L. boscii, P. flesus and M. azevia, and in autumn for C. linguatula.

The sex ratio is an important trait of natural populations and a key parameter for assessing the reproductive potential and stock status of exploited fish populations. In fisheries research, knowledge on spatial and temporal sex ratio variation can inform on the capacity of a population to support exploitation and environmental changes. Blue whiting (Micromesistius poutassou) shows sexual growth dimorphism after maturation, with females achieving greater lengths than males. The main goal of this work was to investigate seasonal patterns in the blue whiting sex distribution, size structure and condition in three areas along the Portuguese coast (north, southwest and south), based on bottom trawl surveys performed in autumn and winter between 1998 and 2015. Smaller blue whiting (12-24 cm) were found in shallow areas down to 250-300m while larger individuals (>24 cm) were spread deeper down to 400-500 m. Condition factor Fulton K differed significantly between seasons in all the areas (F = 11.72; p-value <0.001) and between sexes (F = 6.14; p-value <0.05). The proportion of females changed between autumn and winter (x²(1) = 4.38, p = 0.03) and across depths (x²(1) = 4.73, p = 0.03). Thus, this study revealed seasonal and depth variations in the blue whiting sex ratio along the Portuguese coast. [ABSTRACT FROM AUTHOR]

Evaluating the effects of fishing and environmental factors on fish populations are fundamental tenets of fisheries science. In this study, we assess associations between environmental variables (sea surface temperature; North Atlantic Oscillation index; upwelling; wind magnitude; westerly winds; northerly winds; river discharge) and fishing variables (fishing effort) in Diplodus sagus catch rates accounting for regional analyses (northwest coast; southwest coast and Algarve-Algarve south coast). Different time series models for data fitting (multi-model approach) were used. The models were lagged, according to species fishing recruitment age based on the hypothesis that fisheries catches depend on larvae recruitment and survivorship. D. sargus catch rates across areas were unrelated to fishing effort but correlated to environmental variables, with seasonal events explaining much of the variability in trends. On the northwestern coast, the catch rates were mainly set by sea surface temperature (SST) and wind magnitude; however, southwestern coast catch rates were set by NAO winter. On the south coast, only one statistical model (SST, upwelling and westerly winds) associated spring conditions with D. sargus catch rates. The multi-model approach revealed autumn, winter and spring seasonal effects to be related with northwest, southwest and Algarve coastal catch rates, respectively, indicating a possible coastal longitudinal gradient related with given periods of spawning and larval availability. The metadata analysis yielded different results from the regional analyses. In summary, marine resource management should take regional environment characteristics and variability into account when determining sustainable catch rates in given areas for species with high habitat site fidelity. [ABSTRACT FROM AUTHOR]

Time-series models (Dynamic factorial analyses and; Min/max autocorrelation factor analysis) were used to explore the relative influences of environmental variables and fishing pressure of trawl, seine and artisanal fleets on catch rates on Trachurus trachurus in ICES IXa sub-divisions (IXaCN-North coast; IXa- CS-South coast; IXaS-Algarve, South coast, Algarve). Fishing effort influenced catch rates in all areas with a 2 year lag and fishing pressure for each area was related to specific fleet sectors effort. In IXaCN, winter upwelling (spawning peak) and both summer northerly wind and wind magnitude (outside of the spawning peak) were strongly correlated with catch rates. In IXaCS summer/autumn westerly winds were related with catch rates. Northerly winds in spring, upwelling and SST (winter and autumn) were related with catch rates in IXaS-Algarve. For species with a long spawning season such as horse mackerel, seasonal analyses at broad regional scales can detract from a better understanding of variability in short term sub-stock catch rates. Favorable environmental conditions, even during seasons with low spawning activity can positively affect catch rates. Ignoring the role of regional oceanographic features on the spatial distribution of the sub-stocks when analysing variability in catch rates can lead to poor inferences about the productivity of the populations. [ABSTRACT FROM AUTHOR]

Interactions between cetaceans and the purse-seine fishery operating along the whole Portuguese continental coast were studied based on on-board observations from 2010 to 2011. Cetacean presence and mortality were estimated and characteristics under which interactions were most likely to occur were identified. Observations were made on 163 fishing trips (0.7% of the average annual number of fishing trips) and 302 fishing operations/hauls. Cetaceans were present during 16.9% of fishing events; common dolphins (Delphinus delphis) accounted for 96% of occurrences, mostly overnight in summer and early autumn. Regression models showed that cetacean presence during a fishing set was significantly (p, 0.05) associated with sardine catches, effort, and latitude/longitude. Encirclement and mortality occurred in 2.3 and 1.0% of fishing events, respectively. Encircled species were the common dolphin, bottlenose dolphin (Tursiops truncatus), and harbour porpoise (Phocoena phocoena), but only common dolphin showed mortality (three individuals); raised to fleet level, estimated total mortality rates of common dolphins were 69 (95% CI 37 -110) in the north and 91 (95% O 55 -165) in the south for 2010 and 78 (95% O 47 -140) in the south only for 2011. The estimated annual mortality rate due to purse seining is 113 (95% CI 3 - 264) common dolphins, which is ~0.63% of the current most optimistic estimate of population size for the Portuguese fishing area (SCANS II). The wide confidence limits, as well as variation between years, reflect low observer coverage, emphasizing the need for increased monitoring to cover gaps in the spatial and seasonal distribution of observer effort and provide reliable estimates of bycatch. [ABSTRACT FROM AUTHOR]

The branched vs. isoprenoid tetraethers (BIT) index, which is based on the relative abundance of non-isoprenoidal, so-called branched glycerol dialkyl glycerol tetraethers (brGDGTs) versus a structurally related isoprenoid GDGT “crenarchaeol”, has been used to trace soil organic carbon (OC) from the continent to the ocean. However, it has been found in some locations that the BIT index can be primarily influenced by crenarchaeol concentrations and brGDGT production in fresh water rather than by soil-derived brGDGT concentrations. This may hamper the application of this proxy as an indicator for the input of soil OC. In order to constrain the applicability of the BIT index along the southern Portuguese continental margin, we examined the source of brGDGTs and crenarchaeol, by investigating their concentration and distribution as well as variations in the BIT index in marine surface sediments from five transects (Douro, Mondego, Estremadura, Tagus, and Sado) and in marine suspended particulate matter (SPM) from the Douro and Tagus transects. Higher BIT values and brGDGT concentrations (normalized to OC content) were found close to the river mouths and coast than in deep offshore sites. This clearly indicated the continental input of brGDGTs and revealed that, at least in this setting, the BIT index was primarily influenced by the delivery of brGDGTs from the rivers. BrGDGT concentrations and distributions in sediments and SPM close to the rivers were similar to those of SPM in the Tagus River. This indicates that degradation processes in the estuaries had no significant effect on the riverine brGDGTs. Therefore, brGDGTs should be a good indicator for the recalcitrant OC fraction transported from the continent to the ocean. Our results also indicated that there are multiple sources of brGDGTs in the marine environment, i.e. the water column and the sediment, which complicates the use of the brGDGT distribution as an indicator for terrestrial vs. marine produced brGDGTs. [ABSTRACT FROM AUTHOR]

Sewage pollution is a worldwide concern and can result in increasing levels of trace elements in the environment that can pose serious risks both to wildlife and human health. This highlights the importance of studying the role of sewage discharges in the contamination of aquatic systems, especially in rocky shores, since part of our food resources is directly collected from coastal waters. For this purpose, the accumulation of trace elements (Cu, Zn, Pb, Ni, Co, Cd, Fe, Mn, and As) by edible molluscs (Mytilus galloprovincialis,Patella ulyssiponensis, andPhorcus lineatus) was compared between one sewage-impacted area and two reference areas. This study suggests that the concentrations of trace elements in the soft tissues of the selected molluscs can be affected by the presence of sewage discharges, and that limpets seem to be the best bioindicator. Moreover, the sewage pollution increased the concentrations of As in the mollusc species, emphasizing its potential damaging effects on natural systems and on edible species. [ABSTRACT FROM AUTHOR]

This study presents a 1-year synopsis of the trawl fishery for the European squid Loligo vulgaris in Portuguese waters, integrating length-structured landings with corresponding geo-referenced fishing activities. From vessel monitoring system (VMS) data, landings and biological sampling, a 'status-report' was obtained for 2003. Fishing pressure was found to be most intense in inshore areas of the northwest and the south coasts. Population size structure, classified into three categories, was not uniform throughout the fishing areas. Larger squid are found offshore in the northwest (International Council for the Exploration of the Sea-ICES rectangle 10E0) and in the south (rectangles 2E1 and 3E1), whereas all inshore western coast rectangles showed larger proportions of small squid relative to the southern rectangles. The analysis carried out in this study provides an insight into the possible impact of the fishing intensity pattern on the population structure in various zones. The results demonstrate the benefits of combining geo-referenced fisheries information with landings and size data, to produce explicit spatio-temporal information that can contribute to integrated planning and management for the sustainable exploitation of this resource. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the importance and the implication of the climate changes on coastal areas may be one of the major issues for this and next centuries. Climate changes may, indeed, impact the nearshore marine ecosystem, as coastal areas are very sensitive to the strength and the variability of the meteorological forcings. The main purpose of this work is to study temperature and phytoplankton distributions along the Portuguese near coastal zone during upwelling events in the present climate conditions and in a future climate scenario. The SRES-A2 IPCC scenario has been considered. We have used a three-dimensional model for coastal and shelf seas, including the following sub-models: hydrodynamical/physical, biological, sediment and contaminant. The forcings are provided by the interactions at the air–sea, considering the wind intensity and direction with the help of the WRF model (Weather Research and Forecast Model) and the coupled atmosphere–ocean model ECHAM5/MPI-OM. Results show that, for the future climate scenario, there is a reinforcement of the southward wind. The responses of the coastal ecosystem corresponds to the reinforcement of both, the southward (up to 10cm/s) and the westward (up to 6cm/s) induced upwelling currents. This, in turn generates an enlargement of the near coast upwelled cold layer, extending up to 60km, as well as the rise of the warm layer temperature (up to 2.0°C) and the spreading of the phytoplankton offshore. Significant changes in both the Chl-a vertical and the horizontal distribution patterns have been observed, as the nutrient supply to the upper layers depends on the strength of the upwelling, the bottom topography and orography of the coastal. These results confirm that changes in the strength and eventually the frequency of the upwelling favourable wind impact the phytoplankton distribution, which can have significant effect in the distribution and population of the upper level of the trophic chain of the coastal ecosystem. [Copyright &y& Elsevier]

Total and organic mercury concentrations were determined in the liver, kidney, muscle, skin, brain and blubber collected from 12 common dolphins, Delphinus delphis, stranded along the Portuguese coast between 1998 and 2003. The liver was the preferential organ for Hg accumulation, while the lowest values were detected in the blubber. Total and organic Hg concentrations in the liver, skin and blubber of dolphins were positively correlated to the levels found in muscle. Positive correlations were also observed between liver and kidney, and skin and blubber. Muscle levels increased linearly with length, while those of liver and kidney varied exponentially for skin, brain and blubber, were sparse. The percentage of organic Hg decreased linearly with length in muscle and exponentially in liver and kidney, accounting for only 10–30% of the total Hg in adults. The concentrations found in this work were lower than those reported by other authors for the same species from southern European coasts.

In order to investigate the feeding habits of Helicolenus dactylopterus dactylopterus along the continental Portuguese coast, a total of 619 individuals were sampled of which 60% contained food in their stomach and 35% had more than one prey item. Among the 81 prey items that were identified in the stomachs, benthic and benthopelagic prey prevail on this species diet. Acantephyra sp, Pasiphaea sp, mysidacea, and teleostei n.i. were the prey with the higher percent index of relative importance (%IRI) value. Three length groups (5-20 cm, 21-27 cm, and 28-48 cm) were defined through cluster analysis of the mean abundance of prey items. A permutational MANOVA detected significant differences in the diet and stomach fullness index for TLG, season, and maturation stage. Smaller fishes had a generalized diet, feeding mainly on mysidacea changing their diet above 20 cm TL, where a major consumption of natantia was found. The larger individuals, >28 cm TL, present a less generalized diet with pisces as dominant prey group. Seasonally, natantia and pisces were the principal prey groups during spring and winter, respectively, while mysidacea and other crustaceans were predominant during the rest of the year. Mysidacea were also the main prey group for immature individuals while natantia and pisces were the principal prey groups to the other maturity stages. The results of this study indicate that H. d. dactylopterus has a diverse diet focused on small crustaceans such as misyds and as specimens grow shrimps and fishes become more consumed, with larger specimens having a more specialized diet. The different nutritional needs during spawning season also seemed to influence the feeding habits of H. d. dactylopterus. [ABSTRACT FROM AUTHOR]

Abstract: Benthic macroinvertebrates communities are the most consistently emphasized biotic component of aquatic ecosystems and are one of the biological indicators required for assessment by the European Water Framework Directive. In this context, several indices based on these communities have been developed in order to assess ecological quality of estuarine systems. In the present work we used AMBI, M-AMBI, BENTIX and BAT to distinguish ecological status of five small estuarine systems of the Portuguese south and southwest coasts. Although indices outputs did not differ between systems and sampling seasons, results indicated that the metrics in which these indices are based could differentiate community structures as a result of two main gradients that force these communities: the natural variability, and the anthropogenic impact. [Copyright &y& Elsevier]

Abstract: Organotin compounds (OTs) are ubiquitous in the marine environment and high concentrations (μgg−1 range) in sediments from different coastal areas around the world have been reported. However, few reports have described the OTs contamination status in the offshore and deep sea environment. This work investigated organotin levels in Nazaré canyon for the first time. Levels of monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPT), triphenyltin (TPT), dioctyltin (DOT) and trioctyltin (TOT) were quantified in sediment samples from the upper flanks of the canyon and from the adjacent coastal area. TBT levels detected in the canyon flanks are about two to three orders of magnitude lower than those found in the coastal area. Nevertheless, when quantifiable, TBT levels in the canyon samples were higher than the Environmental Assessment Criteria set for TBT in sediments by the OSPAR Commission indicating that at those locations negative ecological impacts are likely to occur. [Copyright &y& Elsevier]

An investigation of the distribution and general biology (size, maturation and fecundity) of the sepiolid Sepietta oweniana off the Portuguese Coast is presented based on 594 specimens collected during research cruises between 1997 and 2008. Statolith microstructure was examined in 35 animals. S. oweniana was mainly encountered on the southwestern and southern continental slopes, while it was rare north of 38°N. Female mantle length (ML) ranged from 13.9 to 35.7 mm, male ML from 12.5 to 28.0 mm; specimens of both sexes being significantly larger in the southeastern area. Potential fecundity was 18–616 (mean 234±104) oocytes and mean mature oocyte diameter varied 2.3–3.4 mm. The year-round presence of mature animals, asynchronous ovulation, the presence of mature specimens over a range of different sizes and the occurrence of feeding activity throughout spawning are indicative of a continuous spawning strategy in this species. Growth increments were present in all statoliths, being narrow and nearly uniform in width. The total number of growth increments registered from the specimens sampled varied between 103 and 179; with a similar range in males (n=17) and females (n=18). Putative age estimates suggest an age approximation of 4.5–6 months for mature and spent females and 5–5.5 months for mature males. [ABSTRACT FROM PUBLISHER]

In the Portuguese southern coast, national and international appeal turns it into a highly relevant area concerning the country's economy. Vale do Lobo is a resort located in the centre of this coast, where the beach has been suffering from erosion problems for several years now. Local interventions have been executed in order to prevent the erosion of the beach, yet the efficiency of such strategy has not been verified. This study's main purpose is to enable a better understanding of the evolutionary trends of the coastline between the Quarteira and Ancão inlet and to analyse the efficiency of the beach nourishment interventions as a protection technique for a coastal environment with the wave energy exposure and geomorphologic characteristics of the present one. The study focussed on a 10-year period, during which, 700x10³ and 370x10³ m³ of sand with D50=0.76 mm (slightly larger than the D50 of the native beach) were extracted from offshore, and deposited in the foreshore. The wave climate in the study area was processed, analysed and used as input for modelling the nearshore processes. In addition, beach profiles measured alongshore have been analysed to obtain the representative beach profile. Coastlines of different dates have been derived from aerial photographs. The longshore transport model Litdrift and the coastline model Litline were applied to study the sediment dynamics. Litdrift was used to estimate the longshore transport capacity of the beach for the hydrodynamic series considering the representative beach profile previously obtained. These results were then used to calculate the evolution of the coastline due to the incident wave climate with Litline model. Aerial photographs were used to verify the model. The analysis of the two beach nourishments performed allowed inference on the efficiency of this coastal protection technique to delay the erosion process. [ABSTRACT FROM AUTHOR]