Recreational harvesting of the wedge clam (Donax trunculus) in southern Portugal: characterization of the activity based on harvesters’ perception and local ecological knowledge

This study was the first attempt to characterize the recreational harvesting of the wedge clam (Donax trunculus). For this purpose, 403 face-to-face interviews were performed in the summers of 2018 and 2019 in southern Portugal. The majority of the harvesters frequented the selected beaches during holidays and collected wedge clams as a hobby for an appetizer. The respondents reported an inter-annual variation in their catches of wedge clam with a decreasing abundance in 2018 followed by a recovery in 2019, but with more recreational harvesters collecting undersized individuals. Although most harvesters declared to consume D. trunculus, only a few bought wedge clams being the clams' size a secondary factor in their valorization. The majority of the recreational harvesters did not know the species' minimum conservation reference size nor the legally allowed maximum daily catch. It was estimated that recreational harvesters can collect 13 tonnes of wedge clams during the summer season along the southeastern coast of Algarve. Even though manual harvesting is not an efficient fishing technique, the lack of selectivity of harvesters can eventually compromise the resilience of D. trunculus populations. Despite most respondents affirmed to get informed about marine biotoxins, most surveys were done during periods of interdiction for shellfish harvesting. The present results revealed that the population is still unaware of the health risks of consuming shellfish contaminated with biotoxins. Educational activities and awareness campaigns are required to further inform recreational harvesters about the regulations in force for this activity and the sanitary threats of marine biotoxins.VENUS” Ref. 0139_VENUS_5_E. 2017–2019; VENUS ref. IPMA-2018-008-BI;info:eu-repo/semantics/publishedVersio

Effects of inter-annual freshwater inflow shifts on the community structure of estuarine decapods

The objective of this study was to evaluate how inter-annual changes in freshwater inputs have affected the decapod assemblages in the Guadiana estuary. Three major areas in the estuary were sampled during the summer, in 2001 (high inflow year and before the filling of the Alqueva dam), in 2002 (low inflow and after filling of the Alqueva dam), and in 2008 and 2009 (low inflow and after consolidation of the impacts of the Alqueva dam). A significant increase in total decapod densities was recorded for the entire estuary, but especially in the upper estuary, after the closure of the dam in 2002. Changes in salinity, turbidity and temperature, which were mainly due to changes in freshwater input and climatic influence (North Atlantic Oscillation index), had an important influence on the structure of the decapod crustacean assemblages. The major conclusions of the study were that, following the construction of the Alqueva dam and regularization of the freshwater inflow, the decapod crustacean community in the Guadiana estuary changed and a shift of the dominant decapod species to upper zones of the estuary happened. These changes, and the presence of the non-native Palaemon macrodactylus in 2008 and 2009, further enhance the importance of estuarine monitoring studies to improve ecologists’ knowledge on distinguishing and understanding natural changes and anthropogenic impacts in the ecosystem.Effets des variations interannuelles d’apports d’eau douce sur la structure d’une communauté estuarienne de décapodes. L’objectif de cette étude était d’évaluer comment les variations interannuelles d’apports d’eau douce affectent l’assemblage de décapodes dans l’estuaire du Guadiana. Trois grands domaines de l’estuaire ont été échantillonnés en été : en 2001 (année d’apports importants et avant le remplissage du barrage d’Alqueva), en 2002 (faible apport d’eau douce et après le remplissage du barrage d’Alqueva), en 2008 et 2009 (après la consolidation de l’impact du barrage d’Alqueva). Une augmentation significative de la densité totale des décapodes pour tout l’estuaire a été enregistrée, mais surtout dans l’estuaire supérieur, après la fermeture du barrage en 2002. Les variations de salinité, turbidité et température, principalement dues à des changements d’apports d’eau douce et à l’influence du climat (indice d’oscillation nordatlantique), ont eu une influence importante sur la structure des assemblages de crustacés décapodes. Les principales conclusions de l’étude sont que, à la suite de la construction du barrage d’Alqueva et de la régulation de l’apport d’eau douce, la communauté de crustacés décapodes dans l’estuaire du Guadiana a changé et les principales espèces de décapodes se sont déplacées vers les zones supérieures de l’estuaire. Ces changements, ainsi que la présence de l’espèce non native Palaemon macrodactylus en 2008 et 2009, soulignent l’importance de surveiller l’estuaire dans le futur proche afin de pouvoir mieux distinguer et comprendre les changements naturels et les impacts anthropiques sur l’écosystème

Macrobenthic response to sewage discharges in confined areas from coastal lagoons: implication on the ecological quality status

We studied the effect of wastewater on macrobenthic assemblages and local Ecological Quality Status (EcoQS) along a pollution gradient. The study consisted of six sampling sites surrounding the discharge channel of a Wastewater Treatment Plant located within Ria Formosa coastal lagoon. The total number of individuals was significantly higher at the discharge point comparatively to the control site, while total number of species, species richness and diversity values revealed the opposite pattern. Deposit-feeding were the most abundant trophic group, particularly at the inner sites, while the highest contributions of suspension-feeding and carnivory groups were observed at external ones. The organic matter content was positively correlated with the deposit-feeding group conferring a structural character of this variable near the plant discharge. M-AMBI index was consistent with the ANOSIM and SIMPER analysis, successfully separating the sampling stations according to the distance from the discharge and distinguishing the lower EcoQS of the inner sites not complying with the requirements of the Water Framework Directive of a “Good” quality status. In addition, changes in ecological and biotic indices were negatively correlated with variations of organic matter and positively correlated with salinity, corroborating the effect of these variables on the composition and structure of macrobenthic communities

International Centre for Coastal Ecohydrology: applying the ecohydrology approach for the sustainable functioning of coastal ecosystems

Coastal areas are among the most sensitive and productive ecosystems around the world, providing for the subsistence of large numbers of people, particularly in developing countries. Human pressure on coastal areas has dramatically increased during the last decades and climate changes will pose new threats to these areas, as expected from sea-level rise and the decrease in freshwater discharges from rivers (Chicharo et al., 2009). The International Centre for Coastal Ecohydrology (ICCE) a newly approved centre under the auspices of UNESCO, in October 2009, is located in the Algarve region (south Portugal). The centre acts as a facilitator and synergetic structure by providing the articulation of different scientific and institutional stakeholders at national and international levels. ICCE aims are to contribute scientific knowledge, capacity-building, educational and dissemination activities to support, design and implement adaptation and mitigation strategies and policies for coastal zones, including the impacts of climate change, addressing the goals of the Strategic Plan of the 7th Phase of UNESCO-IHP, the Millennium Development Goals (UN-MDGs) and the key themes for the United Nations Decade of Education for Sustainable Development (UN-DESD), particularly in African and Mediterranean regions.info:eu-repo/semantics/publishedVersio

Self-condensation of n-(N-propyl)butanimine: NMR and mass spectral analyses and investigation by theoretical calculation

The stability of N-propylbutanimine (1) was investigated under different experimental conditions. The acid-catalyzed self-condensation that produced the E-enimine (4) and Z-inimine (5) was studied by experimental analyses and theoretical calculations. Since the calculations for the energy of 5 indicated that it had a lower energy than 4, yet 4 was the principal product, the self-condensation of 1 must be kinetically controlled

The influence of submarine groundwater discharges on subtidal meiofauna assemblages in south Portugal (Algarve)

Submarine groundwater discharges (SGD) have been documented as contributing to the biological productivity of coastal areas, through a bottom-up support to higher trophic levels. Nevertheless, the effects on the bottom levels of the coastal food web, namely the meiofauna, are still very poorly known. The “Olhos de Água” beach is the only area on the South coast of Portugal where submarine freshwater seepages have been identified. In this study, meiofauna assemblages in the area impacted by SGD were compared with the meiofauna from a similar area, but without SGD. Samples were taken in Spring and Summer 2011, under different hydrological regimes, aquifer recharge (after Winter) and dryness (after Spring), respectively. The major changes in the community were recorded at a seasonal level, with higher abundances and number of taxa in Spring, when compared to Summer. This may be explained by better sediment aeration during spring along with higher food availability from the sedimentation of spring phytoplankton blooms. Although no significant differences were detected by multivariate analysis on the meiofauna abundances between Control and Impact areas, pair-wise tests on the interactions between factors in number of taxa (S) and species richness (Margalef's d) suggested that the discharge of groundwater stimulated an increase in meiofauna diversity. Such effect can be observed between the meiofauna assemblages from impacted and control areas and also between periods with different discharge regimes (Spring and Summer) in the impacted area. These findings highlight the role that freshwater discharges from coastal aquifers have on meiofauna assemblages and suggest that SGD contribute to enhance the transfer of energy from the lower levels of the trophic web to upper levels

Brazilian cave heritage under siege

info:eu-repo/semantics/publishe

Impacto da ETAR de Faro-Noroeste nas comunidades bentónicas da Ria Formosa

Dissertação de mest., Biologia Marinha, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2007Com o presente trabalho pretendeu-se avaliar o impacto da ETAR de Faro Noreste nas estrutura das comunidades macro e meiobentónicas da Ria Formosa. A amostragem decorreu ao longo do ano de 2006, caracterizando-se o local nas várias estações do ano. As estações de amostragem foram estabelecidas a diferentes distâncias do ponto de descarga de onde se recolheram dados dos parâmetros da água e amostras de sedimento para o estudo da macro e meiofauna bentónica. Os resultados evidenciaram que os efluentes da ETAR impõem um forte impacto na estrutura das comunidades bentónicas mais próximas, essencialmente devido à alteração brusca dos valores de salinidade e ao enriquecimento orgânico que podem provocar períodos de insuficiência na disponibilidade de oxigénio dissolvido. Estes, foram os factores estruturantes das comunidades, tendo sido responsáveis pela baixa diversidade observada perto do ponto de descarga, onde apenas alguns taxa como os nemátodes, as poliquetas da família Nereidae e os bivalves Scrobicularia plana na prevalecem. Estes organismos oportunistas beneficiam de uma grande capacidade de adaptação a estes ambientes , ocorrendo em grandes abundâncias, desempenhando um papel ecológico fundamental nestas zonas afectadas. O efeito dos efluentes foi-se atenuando com o aumento da distância à ETAR, onde a maior circulação e renovação da água terá eliminado o efeito das suas descargas, verificando-se uma maior diversidade de taxa sugerindo um ambiente não impactado. Temporalmente não ocorreram diferenças significativas na estrutura das comunidades bentónicas, com excepção de algumas situações consideradas pontuais. A continuidade do estudo é necessária de modo a poder avaliar mais correctamente a componente temporal e minimizar os erros registados em alguns dos métodos de avaliação utilizados

Seawater acidification by CO2 in a coastal lagoon environment: Effects on life history traits of juvenile mussels Mytilus galloprovincialis

The carbonate chemistry of seawater fromthe Ria Formosa lagoon was experimentallymanipulated, by diffusing pure CO2, to attain two reduced pH levels, by−0.3 and−0.6 pH units, relative to unmanipulated seawater. After 84 days of exposure, no differences were detected in terms of growth (somatic or shell) or mortality of juvenile mussels Mytilus galloprovincialis. The naturally elevated total alkalinity of the seawater (≈3550 μmol kg−1) prevented under-saturation of CaCO3, evenunder pCO2 values exceeding 4000 μatm, attenuating the detrimental effects on the carbonate supply-side. Even so, variations in shell weight showed that net calcification was reduced under elevated CO2 and reduced pH, although the magnitude and significance of this effect varied among size-classes. Most of the loss of shell material probably occurred as post-deposition dissolution in the internal aragonitic nacre layer. Our results show that, even when reared under extreme levels of CO2- induced acidification, juvenileM. galloprovincialis can continue to calcify and grow in this coastal lagoon environment. The complex responses of bivalves to ocean acidification suggest a large degree of interspecific and intraspecific variability in their sensitivity to this type of perturbation. Further research is needed to assess the generality of these patterns and to disentangle the relative contributions of acclimation to local variations in seawater chemistry and genetic adaptation

Synthesis of 2-(alkylamino)-1-phenylethane-1-thiosulfuric acids, potential schistosomicides

The total synthesis of seven here-to-fore unreported aromatic aminoalkanethiosulfuric acids, their physical properties and those of the aminoalcohol and bromoalkanamine intermediates are reported. All structures were established by including ¹H and 13C NMR, IR and MS spectroscopy and elemental analysis