Loading...
32 results
Search Results
Now showing 1 - 10 of 32
- Trophic web structure and ecosystem attributes of a temperate coastal lagoonPublication . Bueno-Pardo, Juan; García-Seoane, Eva; Sousa, Ana I.; Coelho, João P.; Morgado, Mariana; Frankenbach, Silja; Ezequiel, João; Vaz, Nuno; Quintino, Victor; Rodrigues, Ana M.; Leandro, Sérgio; Luis, António; Serôdio, João; Cunha, Marina R.; Calado, António J.; Lillebø, Ana; Rebelo, José E.; Queiroga, HenriqueA high quality data collection has been carried out between 2004 and 2014 to develop the first trophic ECOPATH model for the functioning of the sub and intertidal zones of Ria de Aveiro. This schematic representation allows the characterization of the most important compartments of biomass and flows of energy representing the functioning of the ecosystem, and can be used in the fields of decision-making and management. The model considered 26 functional groups from primary producers to top-predators and two different fisheries (artisanal and leisure), and showed that Ria de Aveiro is a dynamic ecosystem dominated by a high biomass of primary producers, where the transference of energy among compartments is, to a large extent, accomplished through the detritus path. The model also provides several ecological indicators on the state of maturity of the ecosystem, showing that Ria de Aveiro is in an intermediate state of maturity with a relatively complex food web and resilience to environmental changes. As discussed, this state of maturity is probably determined by human action pervading the system to advance in the expectable ecological succession of a coastal lagoon. These aspects, together with indicators of elevated fishing pressure and predation within the system, underline the necessity of controlling illegal extraction activities and monitoring the biomass of the main functional groups of the system, especially top predators, in order to keep the functioning of the ecosystem of Ria de Aveiro in its current condition.
- An overview of jellyfish aquaculture: for food, feed, pharma and funPublication . Duarte, Inês Matos; Marques, Sónia Cotrim; Leandro, Sérgio Miguel; Calado, RicardoInterest on jellyfish research has significantly increased over the last two decades, mostly driven by the potential benefits of their high-end uses. Recent efforts have been put forward towards the commercial use of scyphozoan jellyfish, although the pipeline leading to their full exploitation is still at an early stage of development. Indeed, further research and several technical advances are still required to expand the use of these bioresources to a larger and more sustainable scale. Here, we describe the state of the art of culture systems already available to farm these organisms throughout the different stages of their life cycle and provide an overview of the potential applications of jellyfish aquaculture for food, feed, as source of bioactive compounds for pharmaceutical and other biotechnological applications, as well as to supply the marine aquarium trade. Overall, this work aims to raise awareness on the relevance that jellyfish will likely play on the development of sustainable blue bioeconomy frameworks fostering a sustainable valorisation of marine living resources.
- Trophic links and nutritional condition of fish early life stages in a temperate estuaryPublication . Primo, Ana Lígia; Correia, Catarina; Marques, Sónia Cotrim; Martinho, Filipe; Leandro, Sérgio; Pardal, MiguelThe physiological and nutritional condition of fish larvae affect their survival and thus, the success of estuaries as nursery areas. Fatty acid composition has been useful to determine fish nutritional condition, as well as trophic relationships in marine organisms. The present study analyses the fatty acid (FA) composition of fish larvae during spring and summer in the Mondego estuary, Portugal. FA composition, trophic markers (FATM) and fish nutritional condition was analysed for Gobiidae and Sardina pilchardus larvae and the relationships with the local environment evaluated. Results showed that both taxa differed mainly in the stearic acid (C18:0) and eicosapentaenoic acid (EPA) content, with important amounts in Gobiidae and S. pilchardus, respectively. Gobiidae larvae presenting high nutritional condition and omnivore FATM. Fatty acid composition seems to be related with their natural habitat selection and food availability, while fish larvae nutritional condition also showed a strong link with the water temperature and presence of potential predators. This study suggests that FA composition can be a useful tool in assessing planktonic trophic relationships and in identifying species natural habitat.
- Zooplankton distribution in a marine protected area: The Berlengas Natural Reserve, Western Coast of PortugalPublication . Mendes, Susana; Marques, Sónia Cotrim; Azeiteiro, Ulisses Miranda; Fernández-Gómez, Mª José; Galindo-Villardón, Mª Purificación; Maranhão, Paulo; Morgado, Fernando; Leandro, Sérgio MiguelZooplankton distribution in the Berlengas Natural Reserve (Portugal) was studied over a period of one year (February 2006 to February 2007). Monthly sampling was performed at 6 stations, differentiated according to depth and distance to the coastline. The aim of this study was to investigate the overall zooplankton variability through its different dimensions (space vs. time). The Partial Triadic Analysis (PTA) was used to study the spatial variability of the zooplankton community and its dynamics in time and the dynamic trajectories of the zooplankton species for each site. It was possible to distinguish a neritic-ocean gradient of the zooplankton composition and a temporal variability. Four distinct periods can be highlighted considering the distribution of the dates and the arrangement of the species: (i) the first one comprised August to November, (ii) the second one was related to June and July, (iii) the third one associated with spring (April and May) and, (iv) the latest one was related to winter (February, March and December 2006 and January and February 2007). The PTA method showed the similarities between the successive data tables and proved to be useful for investigating biotic structures and detecting spatial-temporal patterns in zooplankton distribution.
- Praias rochosas do litoral de Peniche: Livro de CampoPublication . Rodrigues, Inês; Mouga, Teresa; Maranhão, Paulo; Leandro, SérgioPeniche é uma cidade do litoral português, sendo a cidade mais ocidental da Europa continental, conhecida pelas excelentes condições para a prática do surf e do turismo de sol e mar. A cidade encontra-se implantada numa península, que em tempos foi uma ilha, repleta de escarpas rochosas e extensas praias arenosas, tanto a sul como a norte. Exibe um vasto património natural e paisagístico, fruto da grande diversidade geomorfológica que constitui a costa: dunas, arribas e recifes rochosos são alguns habitats marinhos característicos. De entre estes, as estruturas rochosas (falésias, afloramentos rochosos, plataformas, entre outros) exibem uma biodiversidade notável, sendo ideais para a observação de organismos marinhos, próprios das zonas litorais.
- Gulls identified as major source of fecal pollution in coastal waters: A microbial source tracking studyPublication . Araújo, Susana; Henriques, Isabel S.; Leandro, Sérgio Miguel; Alves, Artur; Pereira, Anabela; Correia, AntónioGulls were reported as sources of fecal pollution in coastal environments and potential vectors of human infections. Microbial source tracking (MST) methods were rarely tested to identify this pollution origin. This study was conducted to ascertain the source of water fecal contamination in the Berlenga Island, Portugal. A total of 169 Escherichia coli isolates from human sewage, 423 isolates from gull feces and 334 water isolates were analyzed by BOX-PCR. An average correct classification of 79.3% was achieved. When an 85% similarity cutoff was applied 24% of water isolates were present in gull feces against 2.7% detected in sewage. Jackknifing resulted in 29.3% of water isolates classified as gull, and 10.8% classified as human. Results indicate that gulls constitute a major source of water contamination in the Berlenga Island. This study validated a methodology to differentiate human and gull fecal pollution sources in a real case of a contaminated beach.
- Spatial and temporal scales of environmental forcing of Acartia populations (Copepoda: Calanoida) in the Canal de Mira (Ria de Aveiro, PortugalPublication . Leandro, Sérgio Miguel; Tiselius, Peter; Queiroga, HenriqueZooplankton and hydrological data were collected from August 2000 and June 2002 at six stations distributed throughout Canal de Mira (Ria de Aveiro, Portugal). The abundance of Acartia clausi and Acartia tonsa adults and juveniles of Acartia spp. for each station and month were combined in a three-way data matrix, which was decomposed into three two-way matrices corresponding to different modes: biological, time, and space. Cluster analysis applied on the space mode revealed the existence of three different zones as a consequence of zooplankton composition. At each mode, principal component analysis showed strong seasonal variations in zones 1 and 2. A different spatial pattern was found between the periods November 2000–April 2001 and November 2001–April 2002, with the displacement of the highest abundance levels from the middle estuary to near the mouth. The congeneric populations were segregated in space: the A. clausi population was restricted to downstream stations (zone 1), whereas the A. tonsa population dominated the middle estuary. Significant correlations between hydrological parameters and copepod abundance were found to differ from zone to zone. The statistical methodology was a valuable tool to (i) discriminate spatial and seasonal distribution patterns, (ii) define estuarine sections based on the faunistic composition, and (iii) evaluate delayed effects of phytoplankton.
- Do mar para o prato: biologia, ilustração e gastronomiaPublication . Leandro, Sérgio Miguel; Maranhão, Paulo; Barraca, Catarina; Correia, Catarina; Borges, Patrícia; Alexandre, António; Salgado, PedroPara as comunidades dependentes da pesca, a gastronomia de mar assume especial relevo para o seu desenvolvimento económico, contribuindo para a promoção e atratividade do seu território e consequente garante de muitos postos de trabalho. Do mar ao prato - biologia, ilustração e gastronomia integra para cada recurso a biologia/ecologia, o perfil nutricional, a gastronomia tradicional e a gastronomia moderna, salteada com a arte da ilustração cientifica.
- 5-years after-Life Berlengas: Conservation efforts and monitoring in Berlengas Archipelago (2019-2024). Project LIFE Berlengas. SPEA - Portuguese Society for the Study of BirdsPublication . Oliveira, Nuno; Almeida, Ana; Alonso, Hany; Bouça, Alexandra; Costa, M.; Crisóstomo, Paulo; Leandro, Sergio Miguel; Mendes, R. N.; Morais, L.; Mouga, Teresa; Mourato, E.; Nascimento, T; Paiva, V. H.; Silva , C. Pereira da; Andrade, JO pós-LIFE Berlengas teve início em 2019. Neste relatório são apresentadas as tarefas realizadas durante 2019-2024, nomeadamente, monitorização e conservação de aves marinhas, biossegurança, controlo de plantas invasoras e monitorização da flora. Os resultados alcançados em termos de investigação, voluntariado, apoio, visitação e ações de sensibilização são também apresentados. A informação recolhida anteriormente ao pós-LIFE foi compilada de forma a apresentar todas as séries temporais disponíveis. Em termos de aves marinhas reprodutoras, foram monitorizados os tamanhos populacionais, a produtividade, as taxas de sobrevivência individual, seguimento individual, a ocupação dos ninhos artificiais e outras atividades de conservação. As espécies-alvo foram o roque-de-castro Hydrobates castro, a cagarra Calonectris borealis, a galheta Gulosus aristotelis, a gaivota-d'asa-escura Larus fuscus, a gaivota-de-patas amarelas Larus michahellis e o airo Uria aalge. Foram testadas medidas de mitigação para reduzir a captura acidental de aves marinhas e a interação com as pesca durante 229 dias de pesca. As aves terrestres reprodutoras e migradoras foram monitorizadas através de sessões de anilhagem e observações no terreno. Das 72 espécies observadas nas ilhas, foram anilhadas 20 espécies distintas. As medidas de biossegurança foram monitorizadas ao longo de cada ano na ilha da Berlenga. Não foram detetados sinais de roedores nas armadilhas A24 ©GoodNature nem nas caixas-rateiras. Apesar dos cinco alertas da potencial presença de roedores emitidos. As Berlengas continuam livres de roedores. No entanto foi feita a observação de fezes frescas de coelho-bravo Oryctolagus cuniculus em maio de 2024. Anualmente em abril, a vegetação foi monitorizada através de 75 quadrados de 2x2m. A cobertura e diversidade da vegetação aumentou ao longo dos anos, com 2024 a atingir o maior número de espécies registadas - 80. Foi monitorizada uma área de exclusão de gaivota-de-patas-amarelas durante a primavera. Foram observadas diferenças significativas entre as subáreas, com maiores abundâncias de Armeria berlengensis na subárea de exclusão, quando comparada com a área de não exclusão. Os novos rebentos de chorão Carpobrotus edulis foram removidos das áreas intervencionadas no âmbito do LIFE Berlengas, o que resultou num esforço anual de monitorização de 466 pessoas*hora. Desde 2019, foram publicados 16 artigos em revistas científicas. Entre 2019 e 2024, 71 voluntários estiveram envolvidos nos trabalhos das Berlengas. A SPEA implementou 4 projetos para assegurar as tarefas do Pós-LIFE. A visitação na ilha da Berlenga foi monitorizada anualmente. As melhorias que decorreram incluíram a implementação da Capacidade de Carga Humana e a plataforma de acesso à ilha da Berlenga. A câmara "ninho ao vivo" esteve ativa ao longo de todo o período, transmitindo imagens em tempo real a partir de um ninho de cagarra e de um ninho de roque-de-castro, em alternado. Foram desenvolvidas diversas ações para sensibilização e de educação ambiental pela SPEA e ICNF. Tais atividades tiveram como público-alvo os visitantes da ilha da Berlenga, os pescadores de Peniche, grupos internacionais, operadores marítimo-turísticos, professores e alunos das escolas locais.
- Copepod production estimated by combining in situ data and specific temperature-dependent somatic growth modelsPublication . Leandro, Sérgio Miguel; Tiselius, Peter; Marques, Sónia Cotrim; Avelelas, Francisco; Correia, Catarina; Queiroga, HenriqueAlthough growth in adult copepods is frequently assumed to be similar to juvenile growth, some evidence have pointed out that under in situ conditions, it can be lower, with, as a consequence, underestimation of secondary production. In addition, under field conditions, juvenile growth in copepods is close to maximum rates estimated at food-saturated conditions. Based on previous assumptions, this study aimed to test the applicability of a new approach for copepod production estimate, derived from temperature-dependent growth models and in situ data, such as seawater temperature and copepod biomass. For this purpose, site-specific copepod juvenile growth models, defined for Acartia tonsa and A. clausi populations from a Southern European estuary (Canal de Mira, Ria de Aveiro, Portugal), were used and copepod biomass was taken fromzooplankton samples collected during 2 years at six sampling stations. By comparing the obtained results with published data, the feasibility of the approach for copepod secondary production estimates and its applicability in worldwide marine ecosystems was confirmed. Future studies should combine the estimates of adult and juvenile production in order to evaluate its relative contribution and to obtain a more precise estimate of secondary production.