Natividade Vieira

Imposex in Nucella lapillus, a bioindicator for TBT contamination: re-survey along the Portuguese coast to monitor the effectiveness of EU regulation

Imposex, a bioindicator of TBT contamination, was re-examined in 2000, five years after the first survey, in populations of the dogwhelk Nucella lapillus sampled along the Portuguese coast, in order to monitor the effectiveness of the 1993 Portuguese legislation based on EU regulation to restrict the use of TBT-based antifouling paints on ships not longer than 25 m. The results obtained during this study indicate that TBT contamination has increased along the Portuguese coast over the five-year period, indicating an inefficacy of the partial ban. The degree of imposex had increased more near small harbours than near ports supporting commercial vessels.

Cytochrome P450 differences in normal and imposex-affected female whelk Buccinum undatum from the open North Sea.

Normal and imposex-affected female Buccinum undatum were sampled from the open North Sea at three locations, one with low, and two with high shipping densities. Cytochrome P450 components and P450 aromatase activity were determined in the microsomal fractions isolated from pooled digestive gland/gonads. Cytochrome P450 aromatase activity was significantly higher (P < 0.05) in normal females collected in the low shipping density area (1,325 +/- 295 fmol/h/mg protein) than levels from imposex animals from a high shipping density area (620 +/- 287 fmol/h/mg protein). A negative correlation was found between aromatase activity and organotin body burden (r = -0.99). Levels of CYP450, cytochrome b5 and NADPH cytochrome c reductase activity did not show differences among groups. This is the first field evidence of depressed aromatase activity in imposex affected females, although additional research under laboratory controlled conditions is required to fully understand the mechanisms underlying the development of imposex in this species.

Artisanal salt production in Aveiro/Portugal - an ecofriendly process.

Solar salinas are man-made systems exploited for the extraction of salt, by solar and wind evaporation of seawater. Salt production achieved by traditional methods is associated with landscapes and environmental and patrimonial values generated throughout history. Since the mid-twentieth century, this activity has been facing a marked decline in Portugal, with most salinas either abandoned or subjected to destruction, making it necessary to find a strategy to reverse this trend.It is, however, possible to generate revenue from salinas at several levels, not merely in terms of good quality salt production, but also by obtaining other products that can be commercialized, or by exploring their potential for tourism, and as research facilities, among others. Furthermore, with an adequate management, biodiversity can be restored to abandoned salinas, which constitute important feeding and breeding grounds for resident and migratory aquatic birds, many of which are protected by European Community Directives.The aims of this manuscript are to present a brief overview on the current state of sea salt exploitation in Portugal and to stress the importance of recovering these salinas for the conservation of this particular environment, for the regional economy, the scientific community and the general public. The Aveiro salina complex is presented in detail, to exemplify salina structure and functioning, as well as current problems and potential solutions for artisanal salinas.

Toxicity assessment of atmospheric particulate matter in the Mediterranean and Black Seas open waters.

Atmospheric deposition of particulate matter (PM) is recognized as a relevant input vector for toxic compounds, such as polycyclic aromatic hydrocarbons (PAHs), into the marine environment. In this work we aimed to analyse the biological activity and potential adverse effects of PM constituents to aquatic organisms. Organic extracts of atmospheric PM samples from different sub-basins of the Mediterranean and Black Seas were screened using different toxicological tests. A yeast-based assay (AhR-RYA) revealed that dioxin-like activity correlated with the concentration of total PAHs in the PM samples, as well as with their predicted toxic equivalent values (TEQs). Although the zebrafish embryotoxicity test (the ZET assay) showed no major phenotypical adverse effects, up-regulation of mRNA expression of cyp1a, fos and development-related genes (previously described as related to PM toxicity) was observed in exposed embryos when compared to controls. Results showed that mRNA patterns of the studied genes followed a similar geographic distribution to both PAH content and dioxin-like activity of the corresponding extracts. The analysis also showed a distinct geographical pattern of activation of pancreatic markers previously related to airborne pollution, probably indicating a different subset of uncharacterized particle-bound toxicants. We propose the combination of the bioassays tested in the present study to be applied to future research with autochthonous species to assess exposure and potential toxic effects of ambient PM. The present study emphasizes the need for more in-depth studies into the toxic burden of atmospheric PM on aquatic ecosystems, in order to improve future regulatory guidelines.

Toxicity of atmospheric particle-bound PAHs: an environmental perspective

Atmospheric polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that represent a risk not only to humans, but to all living organisms. High-molecular weight PAHs are more toxic than lighter relatives, and also have a higher tendency to bind onto air particles (i.e., particle matter, PM). PM is a major constituent of air pollution. Adequate assessment of the biological impact of PM requires the analysis, not only of the effects on human health, but also on the environment. Since the aquatic systems work as a natural sink to these air pollutants, assessing the effects of particle-bound PAHs on aquatic organisms may further characterize its potential aquatic toxicity, also providing simple and low-cost alternative assays to investigate PM biological effects in vivo. We review the current scientific literature, addressing the atmospheric PAHs fate, transformation and deposition, pertinent particle-bound PAHs toxicity data, and the potential aquatic toxic burden. Conceptual and experimental procedures that could improve future investigations and risk assessments are also considered.

Drifting towards the surface: A shift in newborn pipefish's vertical distribution when exposed to the synthetic steroid ethinylestradiol

Endocrine disrupting chemical (EDC) effects during early life have the potential to modulate population structure, either directly through increased mortality or by causing inappropriate aggregation events, thus affecting the number of young that will reach adulthood. An alteration in the dispersal and recruitment patterns can also impair the connectivity among geographically distant populations. However, the detection of EDC-induced effects occurring after egg hatch, when newborns increase their chances of contacting with environmentally dispersed contaminants, is not a simple process as effects might be masked by the large natural mortality rates that usually occur during fish early life. Since there is a lack of information regarding the impact of EDCs on fish early life dispersal patterns, particularly on vertical migrations patterns, the effects of environmentally relevant concentrations of EE(2) on the vertical distribution of newborn fish was assessed through an ex situ exposure experiment. Syngnathus abaster newborns were exposed to EE(2) (nominal concentrations of 8, 12 and 36 ng L(-1)) and the dynamics of their vertical distribution was monitored for up to 40 d. No significant differences in overall mortality were observed between treatments or in the dynamics of the registered death curves. Nevertheless, an alteration in the distribution patterns was observed. The commonly benthic newborn tended to shift their vertical distribution towards the surface, in a dose-dependent manner. Curiously, a follow up of the exposed pipefish confirmed that EE(2) effects were also noticeable upon sexual maturity, namely by the alteration of several primary and secondary sexual characters. The observation that vertical distributional patterns, at least in pipefish, are clearly altered at environmentally relevant EE(2) concentrations indicates that EDCs impact in fish larvae behaviour should be considered when addressing the effects of contaminants, given the obvious implications on population connectivity, stability and persistence.

Estrogenic chemical effects are independent from the degree of sex role reversal in pipefish

Endocrine disrupting chemicals (EDCs) have been reported to disturb several ecological relevant endpoints. Surprisingly, EDC-induced effects on fish sexual behaviour have been poorly studied despite the fact that even subtle alterations might contribute to a disruption of sexual interactions, thus negatively impacting reproduction. As the few assessments on sexual behaviour have been conducted in species with orthodox sex roles, it might be argued that sex-role reversed species might provide a potentially complementary system to further explore the effects of EDCs on reproduction. In the present study, two pipefish species with distinct degrees of sex-role reversal were selected to further elucidate the impact of chronic EE2 exposure on sexual behaviour and reproduction-related endpoints. The obtained results indicate that, independently of the degree of sex role reversal, courtship behaviour seems to resist oestrogenic chemical exposure. However, exposure to environmentally relevant EE2 levels did induce a complete absence of pregnancies at 18 ng/L. Even though pregnancies were observed at intermediate concentrations, the percentage of non-transferred or misplaced oocytes increased and a dose-dependent decrease of oocyte volume was observed. Imbalances in the oogenesis process, induction of vitellogenin in males and the absence of pregnancies highlight that environmental relevant concentrations of EE2 have the potential to negatively affect pipefish populations, most of them inhabiting coastal areas where oestrogenic contamination is more prevalent.

Sexing blennies using genital papilla morphology or ano-genital distance

Information on the genital morphology of male and female Lipophrys pholis is provided, as well as for two other sympatric blenniid species, Coryphoblennius galerita and Lipophrys trigloides. The use of non-invasive sex determination procedures described may be extremely useful not only for ecological studies but also as a proxy for the detection of environmental exposure to endocrine disruptive chemicals, given that blennies have been proposed as potential sentinel species for chemical contamination.

Can season interfere with diatom ecological quality assessment

To understand whether seasons influence the ecological quality assessment of streams on the basis of diatoms, a study was undertaken in two lowland water courses located in northwest Portugal, between autumn 2008 and summer 2009. Temporal variation in the chemical pollution of these streams was small as revealed by a number of physical and chemical parameters analyzed. PERMANOVA global test revealed significant variation in water temperature among seasons. The diatom communities also showed a temporal variation although not all the seasons were statistically different. The multidimensional scaling analysis showed that the main differences in the diatom communities were between two groups of seasons: autumn/winter and spring/summer. Species such as Cocconeis pseudolineata, Gomphonema parvulum var. exilissimum, Fragilaria vaucheriae, Encyonema minutum, and Nitzschia recta were more abundant in spring/summer, while species such as Mayamaea atomus and Nitzschia pusilla were more abundant in autumn/winter. The BIOENV routine confirmed that the biological and temperature patterns are highly correlated. Despite the effects observed on diatom communities, these differences were buffered by the EQR (IPS) values which do not reflect seasonal differences. Therefore, the use of the index IPS seems to allow the monitoring of the streams’ ecological quality throughout the year without the interference of the natural temporal variability of diatom communities.

Evaluation of the water quality and biotic communities of two Portuguese reservoirs (Alto Lindoso and Ermal) and their relationship with recreational fishing

Alto Lindoso (Lima basin) and Ermal (Ave basin) dams (Fig. l) were built originally for the p_roduction of hydroelectricity but other uses of these reservoirs have evolved. These include recreational uses bathing, aquatic sports and angling. Al! these activities constitute potential pollution sources. Although anglers fish in both reservoirs, the Ermal Reservoir has higher angling pressure from a higher number of competition events than the Alto Lindoso Reservoir. The systematic use of baits poses potential risks for water quality, the established community and biological productivity.