Tools for the management and conservation of the European eel (Anguilla anguilla): an application to Santo André lagoon

The critical status of the European eel (Anguilla anguilla) population is an ongoing concern for fisheries and environmental managers. The European Eel Regulation approved in 2007 established the framework for the eel recovery, although incomplete knowledge about the stock hampers management that ensure the species’ sustainability. The present research investigated the dynamics of the European eel in a coastal lagoon, contributing to increase the knowledge about the species and to the assessment of the status of the stock in Portuguese inland waters. The information gathered on eel recruitment, and on the species exploitation and life history traits in a Portuguese brackish system, the Santo André lagoon, provided relevant data to develop stock assessment tools, and to analyse and understand the impact of management decisions on the local eel stock. Data on glass eel from the rivers Minho and Lis provide insights on recruitment trends in Portugal in recent decades and on the drivers of glass eel ingress into Portuguese coastal systems and were used as a proxy to the recruitment dynamics in Santo André lagoon. Results suggest that eel recruitment shows no evidence of a dramatic decline in Portugal, compared to trends reported for other European rivers. The dynamics of the eel population in continental waters was studied from a socio-economic and biological perspective in Santo André lagoon, where the eel yield is significant. The fishery statistics since the 1980’s and the field work conducted in 2011/12 and in 2015/16 have made possible to gather relevant information on the exploitation and biology and have provided the necessary data to characterize the local eel population. Data collected were used to calibrate a Bayesian state-space Integral Projection Model (SSIPM) that described the eel dynamics in the lagoon and estimated relevant eel biomass indicators. The eel population in the lagoon is male-skewed and characterized by a relatively young population (average age is 2.3 years), with only 13.7 % of individuals above 350 mm (13.7%). Eel growth in the lagoon is among the fastest reported for the species and explains the early onset of maturity in males, which metamorphose into silver eels, on average, at three years of age. The male dominance in the lagoon is most likely related to the high eel density estimates obtained with the SSIPM, ranging between 6 and 139 kg ha-1 in the years studied (2008-2017). The high productivity of the system supports one of the highest eel fishing yields in the species’ range, which represents a substantial share (50%) of local fishermen’s income. The increase in the catch per unit effort between 2006 and 2017 obtained from fisheries statistical data, was hypothesized to be a consequence of fishing effort reduction under the eel regulation, combined with an increase in natural recruitment. These results point out to the positive signs of the adaptive approach adopted in local fisheries management, although the eel regulation targets (silver eel biomass escapement) may be compromised. The closed nature of the lagoon translates into a late escapement of silver eels, which occurs only in the spring when the connection to the sea is artificially re-established, making them very vulnerable to capture by the fishery. Despite being an illegal activity, silver eel fishing occurs, showing that the management system must be improved. There are conditions to implement fisheries co-management in this socio-ecological system, and the estimated fishing yield and silver eel escapement under different management scenarios suggest that there are opportunities to improve the sustainability of the local European eel population. The SSIPM developed proved to be a useful tool to describe the European eel population in Santo André lagoon and can be used to support the evaluation of the Portuguese eel management plan, particularly in coastal brackish systems. The framework can be adapted to other eel habitats where eel abundance time-series are available, ideally incorporating information on sex ratio, growth, and length at silvering of the local population, since those life history traits are environmentally dependent

Tools for the management and conservation of the European eel (Anguilla anguilla): an application to Santo André lagoon

The critical status of the European eel (Anguilla anguilla) population is an ongoing concern for fisheries and environmental managers. The European Eel Regulation approved in 2007 established the framework for the eel recovery, although incomplete knowledge about the stock hampers management that ensure the species’ sustainability. The present research investigated the dynamics of the European eel in a coastal lagoon, contributing to increase the knowledge about the species and to the assessment of the status of the stock in Portuguese inland waters. The information gathered on eel recruitment, and on the species exploitation and life history traits in a Portuguese brackish system, the Santo André lagoon, provided relevant data to develop stock assessment tools, and to analyse and understand the impact of management decisions on the local eel stock. Data on glass eel from the rivers Minho and Lis provide insights on recruitment trends in Portugal in recent decades and on the drivers of glass eel ingress into Portuguese coastal systems and were used as a proxy to the recruitment dynamics in Santo André lagoon. Results suggest that eel recruitment shows no evidence of a dramatic decline in Portugal, compared to trends reported for other European rivers. The dynamics of the eel population in continental waters was studied from a socio-economic and biological perspective in Santo André lagoon, where the eel yield is significant. The fishery statistics since the 1980’s and the field work conducted in 2011/12 and in 2015/16 have made possible to gather relevant information on the exploitation and biology and have provided the necessary data to characterize the local eel population. Data collected were used to calibrate a Bayesian state-space Integral Projection Model (SSIPM) that described the eel dynamics in the lagoon and estimated relevant eel biomass indicators. The eel population in the lagoon is male-skewed and characterized by a relatively young population (average age is 2.3 years), with only 13.7 % of individuals above 350 mm (13.7%). Eel growth in the lagoon is among the fastest reported for the species and explains the early onset of maturity in males, which metamorphose into silver eels, on average, at three years of age. The male dominance in the lagoon is most likely related to the high eel density estimates obtained with the SSIPM, ranging between 6 and 139 kg ha-1 in the years studied (2008-2017). The high productivity of the system supports one of the highest eel fishing yields in the species’ range, which represents a substantial share (50%) of local fishermen’s income. The increase in the catch per unit effort between 2006 and 2017 obtained from fisheries statistical data, was hypothesized to be a consequence of fishing effort reduction under the eel regulation, combined with an increase in natural recruitment. These results point out to the positive signs of the adaptive approach adopted in local fisheries management, although the eel regulation targets (silver eel biomass escapement) may be compromised. The closed nature of the lagoon translates into a late escapement of silver eels, which occurs only in the spring when the connection to the sea is artificially re-established, making them very vulnerable to capture by the fishery. Despite being an illegal activity, silver eel fishing occurs, showing that the management system must be improved. There are conditions to implement fisheries co-management in this socio-ecological system, and the estimated fishing yield and silver eel escapement under different management scenarios suggest that there are opportunities to improve the sustainability of the local European eel population. The SSIPM developed proved to be a useful tool to describe the European eel population in Santo André lagoon and can be used to support the evaluation of the Portuguese eel management plan, particularly in coastal brackish systems. The framework can be adapted to other eel habitats where eel abundance time-series are available, ideally incorporating information on sex ratio, growth, and length at silvering of the local population, since those life history traits are environmentally dependent

Inscrições rupestres do Norte de Portugal: novos dados e problemática

O conjunto de várias inscrições rupestres recentemente publicadas insta a uma actualização e reavaliação dos dados já conhecidos, sobretudo no que toca aos textos de carácter votivo ou associados a espaços que se supõem de natureza cultual. Inserem-se neste âmbito os sítios de Pena Escrita (Vilar de Perdizes, Montalegre), Mogueira (Resende, Viseu) e Pias dos Mouros (Argeriz, Valpaços), habitualmente designados como santuários rupestres e que colocam importantes questões de fundo às quais importa tentar responder.Regarding the assemblage of the new rock inscriptions recently published, it is important to make an update and a re-evaluation of the data known so far, above all in what concerns to votive texts or inscriptions associated with supposed cult places. Within this subject, are the cases of Pena Escrita (Vilar de Perdizes, Montalegre), Mogueira (Resende, Viseu) and Pias dos Mouros (Argeriz, Valpaços), considered as rock sanctuaries and revealing background questions that we must try to answer

S-thiolated protein profile to assess the redox-modulation effects of antiretroviral drugs

Efavirenz (EFV) is an anti-HIV drug that has been associated to neurotoxicity. The 8-hydroxy-efavirenz metabolite has been described as the responsible for its long-term neurotoxic effects. Upon bioactivation this metabolite is able to generate electrophilic species, forming protein adducts and eliciting oxidative stress. S-thiolation of proteins (e.g. S-glutathionylation) has been suggested as a mechanism of protein regulation by the redox status. The present study is aimed to investigate if S-thiolated proteins plasma profile (RSSP) is associated with EFV-neurotoxicity. The RSSP was assessed in an animal model of EFV-induced neurotoxicity. The animal RSSP was compared to the one obtained in a cohort of HIV-infected patients on EFV. The dependence on 8-hydroxy-efavirenz generation and the influence of infection in RSSP profile were also assessed in the clinical study. This profile was also compared to the one obtained in patients on nevirapine (NVP), a non-neurotoxic antiretroviral of the same class of EFV. The same RSSP was found in animal model and patients on EFV. This profile is characterized by increased S-glutathionylation and decreased S-cysteinylation of proteins. This is mainly observed in patients that form higher 8-hydroxy-efavirenz, which is in accordance with higher risk of neurotoxicity. RSSP of patients on NVP was the opposite of the one observed for EFV. This might explain why EFV is mostly metabolized by liver, but is barely hepatotoxic. No influence of HIV-infection in RSSP was found. Summing up, we conclude that RSSP profile might be associated with EFV-induced neurotoxicity, suggesting that it is a suitable tool for therapeutic drug monitoring aimed at managing toxic events. Moreover, as EFV and NVP presented a different RSSP signature, this tool might be used for assessing antiretroviral redox-modulation effects and quantification of drug-induced oxidative stress. This knowledge might have important implications for toxicity risk assessment, antiretroviral prescription and drug development

A importância dos fatores estruturais na garantia da segurança alimentar na produção de refeições para escolares

O projeto de construção de um refeitório escolar deverá ser objeto de um estudo aprofundado da sua expectável atividade funcional e operacional e deverá considerar diversos fatores tais como os requisitos legais e as exigências técnicas de produção, de arquitetura e das condições de trabalho, conjugados com possíveis limitações económicas, de modo a garantir o fornecimento de refeições em segurança.Juntamente com a revisão da literatura, foram efetuadas visitas técnicas a unidades de produção de refeições, de modo a verificar in loco o cumprimento dos diferentes requisitos.Das evidências observadas identificaram-se diversas não-conformidades estruturais que afetam o cumprimento das boas práticas de produção de refeições e, que na sua maioria, poderiam ter sido evitadas se, na fase de conceção do projeto, tivessem sido previstas.Seria útil garantir que os técnicos envolvidos no serviço de refeições escolares, nomeadamente nutricionistas, participassem em reuniões multidisciplinares para avaliação de projetos e programas preliminares, contribuindo para a elaboração de um projeto adequado a todas as dimensões intrínsecas à utilização futura deste espaço.The design of school canteens shall be subject to detailed studies regarding its functional and operational activity. It must consider several factors such as legal aspects, production technical requirements, architectural and working conditions as well as economic aspects in order to guarantee the correct and safe supply of the meals.In addition to literature review some technical visits were done to allow the on-site checking of the fulfilment of the several factors considered.Several structural nonconformities were identified that affect compliance with the good manufacturing practices. Most of them could have been avoided if, at the design stage of the project, these factors had been considered.It would be useful to ensure that the different technicians involved in food service, namely nutritionists, participate in multidisciplinary meetings to evaluate base plans, and program briefs in order to achieve a better project proposal

Fotossíntese e acumulação de ácido abcísico em Lupinus albus sujeito a stress hídrico

The objective of the present work was to assess whether the depression of photosynthetic activity in droughted Lupinus albus L. plants was more closely associated with carbohydrate build-up or ABA accumulation. With that purpose we have measured the concomitant drought-induced changes in photosynthetic capacity and the concentrations of Rubisco, chlorophylls, non-structural carbohydrates and ABA in young and old leaves of white lupin plants. Although Rubisco and chlorophylls contents did not decrease with water stress, the photosynthetic capacity was decreased by soil drying, the decline in photosynthesis being more tighly related with ABA accumulation than with sugar content. In contrast to droughted plants, ABA feeding to intact plants resulted in a significant decrease in Rubisco and chlorophyll content. However, no increase in shoot ABA content was detected in ABA-fed plants. Therefore this work is not conclusive as to the correlation between photosynthetic capacity and ABA accumulation in droughted white lupin plants being causal or not

Influence of nutrient availability on drought-induced changes in the activity of antioxidant enzymes in sunflower leaves

We aimed to evaluate if plants with different nutrient availability evidenced a different capacity to overcome drought-induced oxidative stress. Membrane peroxidative damages as MDA concentration and the activity of several antioxidant enzymes were determined in leaves of well watered (WW) and water stressed (WS) H. annuus plants grown either with adequate (Adeq Nutr) or limited (Limit Nutr) nutrient regimes. Constitutive capacity to eliminate ROS was not overall changed by growing plants with different nutrient supply regimes, but a diverse enzyme-dependent response was observed. In response to drought SOD and DHAR activity increased only in plants with limited nutrient supply, while in plants with adequate nutrient supply the activity of these enzymes did not change and were constitutively higher, but the activity APX increased by 50%. The subtle observed changes in the activity of the antioxidant enzymes are discussed, given that no oxidative damage was observed

Response to seasonal drought in three cultivars of Ceratonia siliqua: leaf growth and water relations

The responses of leaf growth and leaf water relations to seasonal drought were monitored, during two successive years, in three cultivars of Ceratonia siliqua L. growing in the field, in the South of Portugal. In leaves from the current year growth bulk leaf water relations parameters were characterised using pressure-volume analysis, and morphometric measurements of xylem in petioles were undertaken. The three cultivars under study (Galhosa, Espargal and Mulata) differed as to the seasonal pattern of leaf initiation: in Galhosa a sharp peak of leaf initiation occurred in June, soon before the period in which the highest leaf expansion rates were determined; on the other two cultivars (Espargal and Mulata), not only the onset of leaf growth occurred earlier, but they continued producing new leaves throughout the summer period. The diurnal pattern of water relations determined in recently-expanded leaves indicated that Galhosa was the only cultivar in which, during midsummer, leaf water potential was not decreased below the turgor loss point and leaf relative water content remained above 90%. Although no conclusive evidence was found for the occurrence of osmotic adjustment in recently-expanded leaves, during the dry season following leaf formation a seasonal decrease in osmotic potential sufficient to maintain turgor was detected in the leaves of Galhosa but not for the other cultivars. As to the anatomy of the xylem at the petioles, the widest xylem conduits were recorded in Galhosa. This might contribute to explain why in this cultivar midday leaf water potential never decreased below –2.0 MPa even at the end of summer drought season