Browsing by Author "Varandas, Simone"
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- Acoustic barriers as an acoustic deterrent for native potamodromous migratory fish speciesPublication . Jesus, Joaquim; Amorim, Maria Clara P.; Fonseca, Paulo J.; Teixeira, Amílcar; Natário, Silvestre; Carrola, João; Varandas, Simone; Pereira, Luís Torres; Cortes, Rui M.V.This study focused on the use of sound playbacks as acoustic deterrents to direct native potamodromous migratory species away from all kind of traps. The effects of two acoustic treatments, a repeated sine sweep up to 2 kHz (sweep-up stimulus) and an intermittent 140 Hz tone, were tested in three fish species native to Iberia: Salmo trutta, Pseudochondrostoma duriense and Luciobarbus bocagei. In contrast with S. trutta, the endemic cyprinids P. duriense and L. bocagei exhibited a strong repulse reaction to the frequency sweep-up sound. The 140 Hz stimulus did not seem to alter significantly the behaviour of any of the studied species. These results highlight the potential of acoustic stimuli as fish behavioural barriers and their application to in situ conservation measures of native Iberian fish populations, to protect them from hydropower dams. In addition, this study shows that acoustic deterrents can be used selectively on target species.
- Alarming decline of freshwater trigger species in western Mediterranean key biodiversity areasPublication . Nogueira, Joana Garrido; Sousa, Ronaldo; Benaissa, Hassan; De Knijf, Geert; Ferreira, Sónia; Ghamizi, Mohamed; Gonçalves, Duarte V.; Lansdown, Richard; Numa, Catherine; Prié, Vincent; Riccardi, Nicoletta; Seddon, Mary; UrbaÅ„ska, Maria; Valentini, Alice; Vikhrev, Ilya; Varandas, Simone; Teixeira, Amílcar; Lopes-Lima, Manuel; Nogueira J.G.Theidentification of key biodiversity areas (KBA) was initiated by the International Union for Conservation of Nature in 2004 to overcome taxonomic biases in the selection of important areas for conservation, including freshwater ecosystems. Since then, several KBAs have been identified mainly based on the presence of trigger species (i.e., species that trigger either the vulnerability and or the irreplaceability criterion and thus identify a site as a KBA). However, to our knowledge, many of these KBAs have not been validated. Therefore, classical surveys of the taxa used to identify freshwater KBAs (fishes, molluscs, odonates, and aquatic plants) were conducted in Douro (Iberian Peninsula) and Sebou (Morocco) River basins in the Mediterranean Biodiversity Hotspot. Environmental DNA analyses were undertaken in the Moroccan KBAs. There was a mismatch between the supposed and actual presence of trigger species. None of the trigger species were found in 43% and 50% of all KBAs surveyed in the Douro and Sebou basins, respectively. Shortcomings of freshwater KBA identification relate to flawed or lack of distribution data for trigger species. This situation results from a misleading initial identification of KBAs based on poor (or even inaccurate) ecological information or due to increased human disturbance between initial KBA identification and the present. To improve identification of future freshwater KBAs, we suggest selecting trigger species with a more conservative approach; use of local expert knowledge and digital data (to assess habitat quality, species distribution, and potential threats); consideration of the subcatchment when delineating KBAs boundaries; thoughtful consideration of terrestrial special areas for conservation limits; and periodic field validation.
- Alarming decline of freshwater trigger species in western Mediterranean key biodiversity areasPublication . Nogueira, Joana Garrido; Sousa, Ronaldo; Benaissa, Hassan; De Knijf, Geert; Ferreira, Sónia; Ghamizi, Mohamed; Gonçalves, Duarte V.; Lansdown, Richard; Numa, Catherine; Prié, Vincent; Riccardi, Nicoletta; Seddon, Mary; Urbańska, Maria; Valentini, Alice; Vikhrev, Ilya; Varandas, Simone; Teixeira, Amílcar; Lopes‐Lima, ManuelThe identification of key biodiversity areas (KBA) was initiated by the International Union for Conservation of Nature in 2004 to overcome taxonomic biases in the selection of important areas for conservation, including freshwater ecosystems. Since then, several KBAs have been identified mainly based on the presence of trigger species (i.e., species that trigger either the vulnerability and or the irreplaceability criterion and thus identify a site as a KBA). However, to our knowledge, many of these KBAs have not been validated. Therefore, classical surveys of the taxa used to identify freshwater KBAs (fishes, molluscs, odonates, and aquatic plants) were conducted in Douro (Iberian Peninsula) and Sebou (Morocco) River basins in the Mediterranean Biodiversity Hotspot. Environmental DNA analyses were undertaken in the Moroccan KBAs. There was a mismatch between the supposed and actual presence of trigger species. None of the trigger species were found in 43% and 50% of all KBAs surveyed in the Douro and Sebou basins, respectively. Shortcomings of freshwater KBA identification relate to flawed or lack of distribution data for trigger species. This situation results from a misleading initial identification of KBAs based on poor (or even inaccurate) ecological information or due to increased human disturbance between initial KBA identification and the present. To improve identification of future freshwater KBAs, we suggest selecting trigger species with a more conservative approach; use of local expert knowledge and digital data (to assess habitat quality, species distribution, and potential threats); consideration of the subcatchment when delineating KBAs boundaries; thoughtful consideration of terrestrial special areas for conservation limits; and periodic field validation.
- Antibiotic-Resistant Escherichia coli on Asian clam (Bivalvia, Corbiculidea): Case Study in the Tua River, Portugal.Publication . Saavedra, Maria José; Gomes, Sónia; Fernandes, Conceição; Teixeira, Amílcar; Varandas, SimoneAntimicrobial resistance (AMR) is a major global health problem. Water use by human activities represent a natural reservoir of AMR, thus a time-integrated approach is required in aquatic ecosystems. Freshwater bivalves are widely applied as accumulation indicators and monitors of contaminant effects on different levels of biological integration once they are suspension feeders that actively filter, retain and concentrates particles from their surrounding water, including free living or particle-bound bacteria. In this study, we aimed to (i) investigate the genetic diversity of E. coli, (ii) determine the virulence factors of E. coli isolates, and (iii) detect antibiotic resistant E. coli. Samples were collected in the middle sector of the Tua River. Isolates were retrieved in Chromocult® Coliform Agar plates (Merck, Germany). Susceptibility testing was performed by the disc diffusion method, according to the Clinical Laboratory Standards Institute (CLSI), and the screening of phenotypic ESBL production was carried out by the double disk synergy test using cefotaxime (30μg), ceftazidime (30μg), and amoxicillin/clavulanate (20/10μg) acid discs. PCR-based assays were designed for phylogenetic E. coli groups evaluation, resistance and detection of ESBL genes. The E. coli phylogenetic group B1 was the most prevalent (44 %), followed by phylogenetic groups A and D. Phylogenetic groups A and B1 comprised more than half (70 %) of the total E. coli isolated. Our results show that Corbicula spp. provide an efficient, time-integrating tool for identifying/quantifying faecal indicators, including multidrug resistant bacteria.
- Antimicrobial resistance in aeromonads isolated from a tributary of River Douro (Portugal)Publication . Saavedra, Maria José; Fernandes, Conceição; Gomes, Sónia; Monteiro, Sandra Mariza; Cabecinha, Edna; Teixeira, Amílcar; Varandas, SimoneThe inappropriate use of antibiotics, one of the causes for high incidence of antimicrobial resistant bacteria isolated from aquatic environments, represents a danger for aquatic organisms and human health
- Antimicrobial susceptibility profiles of multidrug-resistant aeromonads isolated from Northern Portugal freshwater ecosystemPublication . Varandas, Simone; Fernandes, Conceição; Gomes, Sónia; Monteiro, Sandra Mariza; Cabecinha, Edna; Teixeira, Amílcar; Saavedra, Maria JoséThe inappropriate use of antibiotics, one of the causes of the high incidence of antimicrobial-resistant bacteria isolated from aquatic ecosystems, represents a risk for aquatic organisms and the welfare of humans. This study aimed to determine the antimicrobial resistance rates among riverine Aeromonas, taken as representative of autochthonous microbiota, to evaluate the level of antibacterial resistance in the Tua River (Douro basin). The prevalence and degree of antibiotic resistance were examined using motile aeromonads as a potential indicator of antimicrobial susceptibility for the aquatic environment. Water samples were collected from the middle sector of the river, which is impacted by several anthropogenic pressures. Water samples were plated on an Aeromonas-selective agar, with and without antibiotics. The activity of 19 antibiotics was studied against 30 isolates of Aeromonas spp. using the standard agar dilution susceptibility test. Antibiotic resistance rates were fosfomycin (FOS) 83.33%, nalidixic acid (NA) 60%, cefotaxime (CTX) 40%, gentamicin (CN) 26.67%, tobramycin (TOB) 26.67%, cotrimoxazole (SXT) 26.67%, chloramphenicol (C) 16.67%, and tetracycline (TE) 13.33%. Some of the nalidixic acid-resistant strains were susceptible to fluoroquinolones. Multiple resistance was also observed (83.33%). The environmental ubiquity, the natural susceptibility to antimicrobials and the zoonotic potential of Aeromonas spp. make them optimal candidates for studying antimicrobial resistance in aquatic ecosystems. Aquatic environments may provide an ideal setting for the acquisition and dissemination of antibiotic resistance because anthropogenic activities frequently impact them. The potential risk of multi- and pan-resistant bacteria transmission between animals and humans should be considered in a “One Health-One World” concept.
- Antimicrobial susceptibility profiles of multidrug-resistant aeromonads isolated from Northern Portugal freshwater ecosystem.Publication . Varandas, Simone; Fernandes, Conceição; Gomes, Sónia; Monteiro, Sandra Mariza; Cabecinha, Edna; Teixeira, Amílcar; Saavedra, Maria JoséExtensive use of water and anthropogenic activities contribute to water body pollution. Agricultural, urban, and animal waste, often characterized by numerous toxic and carcinogenic chemicals, pathogenic bacteria, and antibiotics, as well as antibiotic resistance genes (ARGs), loaded with microflora, can contaminate water and enter the food chain, posing a considerable danger to public health [1,2]. The inappropriate use of antibiotics, one of the causes of the high incidence of antimicrobial-resistant bacteria isolated from aquatic ecosystems, represents a risk for aquatic organisms and the welfare of humans. Infectious diseases, both human and animal, are closely related through the environment in the One World - One Medicine - One Health concept, in order to deal with the growing problem of antibiotic resistance. Aeromonas spp. can acquire antimicrobial resistance mechanisms, with the potential to spread via horizontal gene transfer, so they could be a good candidate as an indicator to follow antimicrobial resistance dissemination in water [3,4]. This study aimed to determine the antimicrobial resistance rates among riverine Aeromonas spp., taken as representative of the autochthonous microbiota, to evaluate the level of antibacterial resistance in the Tua River (Douro basin).
- Aproveitamento hidroelétrico do baixo Sabor - programa integrado de monitorização ambientalPublication . Santos, Cátia; Varandas, Simone; Hughes, Samantha; Teixeira, Amílcar; Jesus, Joaquim; Pereira, Vitor; Lopes, Marisa; Bessa, Isabel; Albuquerque, António; Cortes, Rui M.V.O Aproveitamento Hidroelétrico do Baixo Sabor (AHBS), localiza‐se na região de Trás‐os‐Montes, no troço inferior do rio Sabor, um dos principais afluentes da margem direita do rio Douro e o primeiro em território português. É composto por duas barragens: escalão de montante ou barragem principal (designada no Estudo Prévio como escalão principal, localização de montante) e escalão de jusante (designada no Estudo Prévio como contraembalse). Estas barragens situam-se no concelho de Torre de Moncorvo e localizam-se, respetivamente, a 12,6 e a 3 km da foz do rio Sabor. A albufeira associada ao escalão de montante estende-se ao longo de 60 Km, ocupando áreas dos concelhos de Torre de Moncorvo, Alfândega da Fé, Mogadouro e Macedo de Cavaleiros. Esta albufeira, com uma capacidade total de 1095 hm3, inunda uma área de 2820 ha ao nível de pleno armazenamento (NPA) à cota 234,00. A albufeira associada ao escalão de jusante estende-se ao longo de 9,6 Km, com uma capacidade total de 30 hm3 inunda uma área de 200 ha ao nível de pleno armazenamento (NPA) à cota 138,00. Os vários estudos efetuados entre 1996 e 2003, incluindo os estudos realizados no âmbito de dois processos de Avaliação de Impacte Ambiental, reconheceram o elevado impacte do AHBS sobre os sistemas ecológicos, nomeadamente devido ao facto do empreendimento afetar significativamente uma área de grande valor para a biodiversidade, reconhecida a nível da União Europeia e, como tal, incluída na Rede Natura 2000. Assim, o Programa Integrado de Monitorização Ambiental (PIMA) do AHBS foi estruturado em duas grandes componentes: a primeira, envolvendo a monitorização geral dos descritores ambientais e a segunda, envolvendo a monitorização das medidas de compensação. Este estudo foca a monitorização do descritor ambiental dos Ecossistemas Aquáticos do PIMA nomeadamente o elemento biológico fauna piscícola em 3 estações em meio lótico e 4 estações em meio lêntico, permitindo uma caracterização da comunidade na fase de enchimento. A amostragem da fauna piscícola em meio lótico foi realizada segundo a Diretiva Quadro da Água. No caso da amostragem realizada nas estações localizadas em meio lêntico, foi utilizada a técnica de captura por redes de emalhar, complementada com a realização de pesca elétrica nas margens. Relativamente às estações localizadas em meio lêntico, foi possível verificar uma disparidade entre as comunidades ictías analisadas nos dois escalões do AHBS e as comunidades presentes nas estações de controlo (cursos de água). Nas estações de controlo as espécies nativas foram dominantes, em número de indivíduos, representando 91% da comunidade, enquanto nas albufeiras dominou a comunidade de espécies exóticas com 81% da comunidade piscícola. As espécies A. alburnus (Ablete) e L. gibbosus (perca-sol) dominaram nas albufeiras de jusante e montante, ao passo que P. duriense (boga-do-Norte) e S. carolitertii (escalo-do-Norte) estiveram presentes em maior abundância nas estações de controlo. Analisando a origem das espécies dentro de cada albufeira verificou-se que, para o escalão de montante, cerca de 77% da população de ictiofauna capturada é exótica e que as espécies nativas representavam, à data, cerca de 22% da comunidade. Relativamente ao escalão de jusante os valores foram semelhantes, apresentando 83% de espécies exóticas e 17% de espécies nativas. Globalmente, a albufeira (escalões de montante e jusante) apresentou 81% de espécies exóticas contrastando com as espécies nativas presentes em apenas 19% da comunidade piscícola amostrada. No conjunto das espécies capturadas no escalão de montante, L. gibbosus representou mais de metade da comunidade amostrada (56%), seguindo-se A. alburnus com 15% e P. duriense (13%), que se encontra atualmente com estatuto de conservação VULNERÁVEL (VU) segundo The IUCN Red List of Threatened Species. Quanto ao escalão de jusante, a espécie A. alburnus dominou, representando 72% da amostra, seguindo-se L. bocagei com 15% e L. gibbosus com 7% do total da comunidade amostrada. A dominância de espécies exóticas tolerantes está associada à alteração do meio lótico para lêntico, acelerando a modificação da composição das comunidades piscícolas constatada entre as estações de controlo e as albufeiras. Esta alteração na composição da comunidade piscícola, com regressão das espécies nativas, foi extremamente rápida imediatamente após o enchimento da albufeira, correspondendo à fase de maturação, a qual evidenciou já uma clara anoxia hipolimnética estival. Este facto demonstra a dificuldade em impor medidas de ordenamento eficazes que evitem a disseminação das espécies exóticas.
- Assessment of a terrestrial protected area for the conservation of freshwater biodiversityPublication . Nogueira, Joana Garrido; Teixeira, Amílcar; Varandas, Simone; Lopes-Lima, Manuel; Sousa, RonaldoFreshwater ecosystems are essential to human well-being and most have high biodiversity. However, this biodiversity has been suffering severe declines owing to the expansion of human activities. Protected areas (PAs) are essential for biodiversity conservation and have proved to be successful in stopping species extirpation if managed properly. Unfortunately, they are usually focused on terrestrial biodiversity, leaving freshwater ecosystems aside. The main goal of this study was to determine the influence of a PA (Montesinho Natural Park (MNP), Portugal) on freshwater biodiversity. Aquatic macroinvertebrates and fishes were surveyed, and biodiversity (richness, abundance, Shannon-Wiener diversity, and Pielou's evenness) and water quality (IASPT) indices were calculated inside, at the periphery and outside the MNP. Results showed that the PA does not affect positively either water quality or the two faunal groups monitored. Macroinvertebrate communities were not influenced by the PA; however, the abundance of pearl mussel Margaritifera margaritifera was significantly higher and size was significantly lower inside the MNP. The richness and abundance of fish communities were significantly higher outside the MNP, except for trout Salmo trutta abundance which was higher inside the MNP. Given these results, the MNP does not guarantee the safeguard of overall aquatic biodiversity and habitats and we propose an extension of MNP to downstream areas in order to increase the number of species (mostly cyprinids) under legal protection. This work demonstrates that terrestrial PA planning and management should also consider aquatic biodiversity to achieve successful conservation.
- Avaliação em escalas múltiplas da variação do meio físico e biológico: da bacia ao habitatPublication . Varandas, Simone; Cortes, Rui M.V.; Teixeira, AmílcarPermanecem pouco testadas e compreendidas as relações entre as características ambientais para múltiplas escalas e o modo como estas influenciam os organismos aquáticos. A heterogeneidade de 4 Tipos de rio (grupos de corpos de água com características geográficas e hidrológicas relativamente homogéneas definidos no âmbito da aplicação da Directiva Quadro da Água – DQA, no seu Anexo II), foi analisada de forma a verificar se essa diversidade se reflectia na distribuição e abundância de macroinvertebrados ao longo de múltiplas escalas espaciais (da bacia ao habitat). Para esta análise, foram colhidas um total de 135 amostras num único período (início do Verão de 2006) e divididas por 15 locais distribuídos por 7 rios sites (4 bacias hidrográficas). Por cada amostra, foi medida a granulometria do substrato, o desvio padrão do substrato, velocidade da corrente, profundidade da massa de água, distância à margem, percentagem de cobertura de macrófitos e parâmetros físico-químicos. A níveis hierárquicos superiores foram ainda avaliados os índices hidromorfológicos HABFLU (Índice de Habitat Fluvial) criado no âmbito da DQA, e os índices que resultam da aplicação do River Habitat Survey (RHS) desenvolvido para o Reino Unido, nomeadamente os índices HQA e HMS. Foram ainda determinadas as condições ecológicas dos diferentes locais de estudo dado possuírem diferentes gradientes de perturbação humana. Recorrendo à análise multivariada apurou-se a percentagem de explicação de cada uma das escalas espaciais de análise.