Metales traza (Cu, Zn, Cd y Pb) en peces juveniles de las guarderías estuáricas a lo largo de la costa portuguesa

Organic and inorganic pollution can impact organisms directly and affect condition, growth and survival of juvenile fish which use estuaries as nurseries, and thereby affect marine adult populations quantitatively and qualitatively. Trace element contamination (Cu, Zn, Cd, Pb) in juveniles of commercial fish Solea solea, Solea senegalensis, Platichthys flesus, Diplodus vulgaris and Dicentrarchus labrax collected in putative nurseries of the main Portuguese estuaries (with diverse intensities and sources of anthropogenic pressures) was determined via atomic absorption spectrometry. Contamination was significantly different among species. Similar levels of contamination were found among estuaries, except for D. vulgaris. Cu and Zn concentrations ranged from 1.0 to 2.1 and 14 to 59 μg g-1 muscle dry weight respectively; while Cd and Pb concentrations were very low. The results indicate that juvenile migration to off-shore habitats is associated with low export of contamination, and no particular estuary increases the potential contamination of adult stocks. This knowledge is of the utmost importance in view of the ecological and economical value of these species and their use of estuarine areas as nurseries.La contaminación orgánica e inorgánica puede afectar a los organismos, a saber al estado fisiológico, crecimiento y supervivencia de los peces juveniles los cuales utilizan los estuarios como guarderías; afectando de forma cuantitativa y cualitativa a la poblaciones marinas adultas. La contaminación de elementos traza (Cu, Zn, Cd, Pb) en las formas juveniles de los peces comerciales Solea solea, Solea senegalensis, Platichthys flesus, Diplodus vulgaris y Dicentrarchus labrax recolectados en guarderías putativas de los principales estuarios portugueses (con diversos tipos e intensidades de presiones antropogénicas) fueron determinados por espectrometría de absorción atómica. La contaminación era significativamente diferente entre especies. Sobre todo se encontraron niveles similares de contaminación entre estuarios, excepto para D. vulgaris. Las concentraciones de Cu y Zn oscilaban desde 1.0 a 2.1 y desde 14 a 59 μg g-1 peso seco muscular, respectivamente, mientras que las concentraciones de Cd y Pb eran muy bajas. Los resultados indican que la migración de los juveniles a mar abierto está asociada a la baja exportación de la contaminación y que los estuarios no amplifican particularmente el potencial de contaminación de los adultos. En vista del valor ecológico y económico de estas especies y del uso de las zonas estuáricas como guarderías, este conocimiento es de vital importancia

Trace metals (Cu, Zn, Cd and Pb) in juvenile fish from estuarine nurseries along the Portuguese coast

Organic and inorganic pollution can impact organisms directly and affect condition, growth and survival of juvenile fish which use estuaries as nurseries, and thereby affect marine adult populations quantitatively and qualitatively. Trace element contamination (Cu, Zn, Cd, Pb) in juveniles of commercial fish Solea solea, Solea senegalensis, Platichthys flesus, Diplodus vulgaris and Dicentrarchus labrax collected in putative nurseries of the main Portuguese estuaries (with diverse intensities and sources of anthropogenic pressures) was determined via atomic absorption spectrometry. Contamination was significantly different among species. Similar levels of contamination were found among estuaries, except for D. vulgaris. Cu and Zn concentrations ranged from 1.0 to 2.1 and 14 to 59 μg g-1 muscle dry weight respectively; while Cd and Pb concentrations were very low. The results indicate that juvenile migration to off-shore habitats is associated with low export of contamination, and no particular estuary increases the potential contamination of adult stocks. This knowledge is of the utmost importance in view of the ecological and economical value of these species and their use of estuarine areas as nurseries

Evaluating estuarine nursery use and life history patterns of Pomatomus saltatrix in eastern Australia

Estuaries provide important nursery habitats for juvenile fish, but many species move between estuarine and coastal habitats throughout their life. We used otolith chemistry to evaluate the use of estuaries and the coastal marine environment by juvenile Pomatomus saltatrix in eastern Australia. Otolith chemical signatures of juveniles from 12 estuaries, spanning 10° of latitude, were characterised using laser ablation-inductively coupled plasma-mass spectrometry. Based upon multivariate otolith elemental signatures, fish collected from most estuaries could not be successfully discriminated from one another. This was attributed to the varying influence of marine water on otolith elemental composition in fish from all estuaries. Using a reduced number of estuarine groups, the multivariate juvenile otolith elemental signatures and univariate Sr:Ca ratio suggest that between 24 and 52% of adult P. saltatrix had a juvenile period influenced by the marine environment. Elemental profiles across adult (age-1) otoliths highlighted a variety of life history patterns, not all consistent with a juvenile estuarine phase. Furthermore, the presence of age-0 juveniles in coastal waters was confirmed from historical length-frequency data from coastal trawls. Combining multiple lines of evidence suggests considerable plasticity in juvenile life history for P. saltatrix in eastern Australia through their utilisation of both estuarine and coastal nurseries. Knowledge of juvenile life history is important for the management of coastal species of commercial and recreational importance such as P. saltatrix.info:eu-repo/semantics/publishedVersio

Otolith geochemistry discriminates among estuarine nursery areas of Solea solea and S. senegalensis over time

Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 452 (2012): 193-203, doi:10.3354/meps09621.Otolith geochemistry is used increasingly as a natural tag to retrospectively determine habitat use in marine fishes. It is necessary to first conduct a thorough assessment of spatio-temporal variability before attempting to use the approach to determine estuarine residency or natal origins. In particular, knowledge of temporal variation at different scales is important when such variability may confound spatial discrimination. We assayed elements and calculated the elemental ratios to Ca (Li:Ca, Mg:Ca, Mn:Ca, Cu:Ca, Sr:Ca, Ba:Ca, Pb:Ca) in otoliths of juvenile Solea solea and Solea senegalensis, collected over several months in 2006 and 2009 in Portuguese estuaries, using laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS). The elemental compositions of the otoliths varied significantly between and within years in both of the species, although the within-year variability did not interfere in spatial discrimination. The overall classification accuracy of juveniles to their estuaries of origin varied among the years and species, ranging from 71.0% to 80.1%. Established elemental signatures constitute the baseline data for future assessments of connectivity between juvenile and adult populations of the two sole species.This study was funded by the ‘Fundação para a Ciência e a Tecnologia’ (FCT), PEst-OE/MAR/UI0199/2011. S. E. Tanner was funded with a PhD grant from FCT (SFRH/BD/40313/2007)

Spatial Variation in Mercury Bioaccumulation and Magnification in a Temperate Estuarine Food Web

Estuaries are renown sinks or repositories of contaminants and reflect historical pollution of persistent compounds. In particular, mercury (Hg) contamination is widespread in coastal environments and occurs in both inorganic (THg) and highly toxic organic forms (OHg) with high bioaccumulation potential. Trophic magnification factors have been increasingly used to quantify biomagnification and represent the average rate of change in contaminant concentration throughout a food web. Here, we assessed small-scale spatial variation in THg and OHg concentrations, as well as variations in local trophic magnification factors in three segregated areas of the Tejo estuary. Selected sites covered a gradient of contamination from industrial Hg hotspots to a natural reserve area, and are key nursery areas for multiple fishes. We analyzed concentrations in sediment and biota, representing the entire local food webs. Samples included sediments, primary producers (salt marsh plants), primary consumers (macrobenthic invertebrates) and top consumers (fish muscle and liver), and the trophic web structure was characterized via SIAR mixed-modeling of nitrogen and carbon isotopic ratios. Spatial variation in Hg concentrations was observed in sediment and biota (but not for all species), with highest concentrations in the area near historical mercury input. Hg concentrations increased with trophic level, and so did the OHg fraction (% of OHg relative to THg), with mean maximum values up to 48.7 and 94.9% in invertebrates and fish, respectively. Trophic magnification factors were positive for all sites (p < 0.05 for all regressions), ranging between 1.56 to 1.76 and 1.78 to 2.47 for THg and OHg, respectively. Overall, rates of mercury bioaccumulation were similar across sites with variations in biota Hg concentrations reflecting baseline differences in site environmental levels. Understanding mercury bioaccumulation and magnification in estuarine biota is critical to safeguard the multiple ecologic functions and economic benefits estuaries provide.info:eu-repo/semantics/publishedVersio

Spatial Variation in Mercury Bioaccumulation and Magnification in a Temperate Estuarine Food Web

Estuaries are renown sinks or repositories of contaminants and reflect historical pollution of persistent compounds. In particular, mercury (Hg) contamination is widespread in coastal environments and occurs in both inorganic (THg) and highly toxic organic forms (OHg) with high bioaccumulation potential. Trophic magnification factors have been increasingly used to quantify biomagnification and represent the average rate of change in contaminant concentration throughout a food web. Here, we assessed small-scale spatial variation in THg and OHg concentrations, as well as variations in local trophic magnification factors in three segregated areas of the Tejo estuary. Selected sites covered a gradient of contamination from industrial Hg hotspots to a natural reserve area, and are key nursery areas for multiple fishes. We analyzed concentrations in sediment and biota, representing the entire local food webs. Samples included sediments, primary producers (salt marsh plants), primary consumers (macrobenthic invertebrates) and top consumers (fish muscle and liver), and the trophic web structure was characterized via SIAR mixed-modeling of nitrogen and carbon isotopic ratios. Spatial variation in Hg concentrations was observed in sediment and biota (but not for all species), with highest concentrations in the area near historical mercury input. Hg concentrations increased with trophic level, and so did the OHg fraction (% of OHg relative to THg), with mean maximum values up to 48.7 and 94.9% in invertebrates and fish, respectively. Trophic magnification factors were positive for all sites (p &lt; 0.05 for all regressions), ranging between 1.56 to 1.76 and 1.78 to 2.47 for THg and OHg, respectively. Overall, rates of mercury bioaccumulation were similar across sites with variations in biota Hg concentrations reflecting baseline differences in site environmental levels. Understanding mercury bioaccumulation and magnification in estuarine biota is critical to safeguard the multiple ecologic functions and economic benefits estuaries provide

Reconciling differences in natural tags to infer demographic and genetic connectivity in marine fish populations

Processes regulating population connectivity are complex, ranging from extrinsic environmental factors to intrinsic individual based features, and are a major force shaping the persistence of fish species and population responses to harvesting and environmental change. Here we developed an integrated assessment of demographic and genetic connectivity of European flounder Platichthys flesus in the northeast Atlantic (from the Norwegian to the Portuguese coast) and Baltic Sea. Specifically, we used a Bayesian infinite mixture model to infer the most likely number of natal sources of individuals based on otolith near core chemical composition. Simultaneously, we characterised genetic connectivity via microsatellite DNA markers, and evaluated how the combined use of natural tags informed individual movement and long-term population exchange rates. Individual markers provided different insights on movement, with otolith chemistry delineating Norwegian and Baltic Sea sources, whilst genetic markers showed a latitudinal pattern which distinguished southern peripheral populations along the Iberian coast. Overall, the integrated use of natural tags resulted in outcomes that were not readily anticipated by individual movement or gene flow markers alone. Our ecological and evolutionary approach provided a synergistic view on connectivity, which will be paramount to align biological and management units and safeguard species’ biocomplexityFundação para a Ciência e a Tecnologia | Ref. UID/MAR/04292/2013Fundação para a Ciência e a Tecnologia | Ref. PTDC/AAG-GLO/5849/2014Fundação para a Ciência e a Tecnologia | Ref. PTDC/MAR-EST/2098/201

Ecotoxicological Effects of the Anionic Surfactant Sodium Dodecyl Sulfate (SDS) in Two Marine Primary Producers: Phaeodactylum tricornutum and Ulva lactuca

Sodium Dodecyl Sulfate (SDS) is an anionic surfactant, extensively used in detergents, household and personal care products, as well as in industrial processes. The present study aimed to disclose the potential toxicological effects of SDS exposure under environmentally relevant concentrations (0, 0.1, 1, 3, and 10 mg L−1 ) on the physiology and biochemistry (photosynthesis, pigment, and lipid composition, antioxidative systems, and energy balance) of two marine autotrophs: the diatom Phaeodactylum tricornutum and the macroalgae Ulva lactuca. A growth rate (GR) reduction in P. tricornutum was observed with a classic dose-response effect towards the highest applied concentration, while a GR increase occurred in U. lactuca. Regarding photochemistry, the decrease in the fluorescence of the OJIP curves and laser-induced fluorescence allowed a better separation between SDS treatments in U. lactuca compared with P. tricornutum. Although all pigments significantly decreased in U. lactuca at the highest concentrations (except for antheraxanthin), no significant variations occurred in P. tricornutum. On the other hand, changes in fatty acid content were observed in P. tricornutum but not in U. lactuca. In terms of classical biomarker assessment, a dose-effect relationship of individual biomarkers versus SDS dose applied; U. lactuca displayed a higher number of biomarker candidates, including those in distinct metabolic pathways, increasing its usefulness for ecotoxicological applications. By evaluating the potential application of optical and biochemical traits, it was evident that the fatty acid profiles of the different exposure groups are excellent candidates in P. tricornutum, concomitant with the characteristics of this anionic surfactant. On the other hand, the results presented by laser-induced fluorescence and some parameters of PAM fluorometry in U. lactuca may be an advantage in the field, offering non-invasive, fast, easy-to-use, high-throughput screening techniques as excellent tools for ecotoxicology assessment.info:eu-repo/semantics/publishedVersio

Ecoengineering Solutions for the Impairment of Spreading and Growth of Invasive Spartina patens in Mediterranean Salt Marshes

The invasion of natural communities by non-indigenous species represents one of the most serious threats to biodiversity. Understanding the ecophysiology of invasive species can provide insights into potential physiological handicaps relative to native species. By doing so, we can leverage the development of ecoengineering solutions for the removal of non-indigenous species, preferably using non-chemical methods. Spartina patens is a known invasive species of cordgrass aggressively proliferating in Mediterranean salt marshes, producing impenetrable monospecific stands. As its occurrence is delimited by the upper high tide water level, we hypothesized that S. patens is intolerant to waterlogging. Therefore, we developed a field experiment where strands of S. patens were kept waterlogged over the entire tidal cycle for 30 days. At the end of the experimental period, plants in the trial plots exhibited severe stress symptoms at different physiological levels compared with control plots (no intervention). At the photobiological level, intervened plants exhibited lower efficiency in producing chemical energy from light, whilst at the biochemical level waterlogging impaired the antioxidant system and increased lipid peroxidation products. Furthermore, the application of chlorophyll a pulse amplitude modulated (PAM) fluorometry, a non-invasive technique, allowed us to evaluate the effectiveness of the implemented measures, being the tool that provided the best separation between the control and intervened population. Considering the physiological traits observed here, ecoengineering solutions based on increased waterlogging of S. patens stands, can be a low-cost and efficient measure to reduce the spreading and growth of this invasive species in the Mediterranean and other salt marshes worldwide with little disturbance.info:eu-repo/semantics/publishedVersio

Water and otolith chemistry: implications for discerning estuarine nursery habitat use of a juvenile flatfish

Variations in otolith elemental composition are widely used to reconstruct fish movements. However, reconstructing habitat use and environmental histories of fishes within estuaries is still a major challenge due to the dynamic nature of these coastal environments. In this study, we performed a laboratory experiment to investigate the effects of variations in salinity (three levels; 5, 18, 30) and temperature (two levels; 16, 21 C) on the otolith elemental composition (Mg:Ca, Mn:Ca, Sr:Ca, Ba:Ca) of juvenile Senegalese sole Solea senegalensis. Temperature and salinity treatments mirrored the natural conditions of the estuarine habitats occupied by juvenile Senegalese sole, thereby providing information on the applicability of otolith microchemistry to reconstruct habitat use patterns within estuarine nurseries, where individual fish move across complex salinity and temperature gradients. While Sr:Ca and Ba:Ca in otoliths were both positively related to salinity, no temperature effect was observed. Partition coefficients, proxies for element incorporation rates increased with increasing salinity for Sr (DSr) and Ba (DBa). In contrast, salinity and temperature had little influence on otolith Mn:Ca and Mg:Ca, supporting physiological control on the incorporation of these elements. Our results are a stepping stone for the interpretation of otolith chemical profiles for fish collected in their natural habitats and contribute to better understanding the processes involved in otolith element incorporation.info:eu-repo/semantics/publishedVersio