38 research outputs found

    Aquacultura Multi-Trófica Integrada (IMTA) e as macroalgas marinhas

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    A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues.O desenvolvimento intensivo da aquacultura nas últimas décadas, bem como a crescente pressão nas zonas costeiras suscitou, e continua a suscitar, muitas preocupações ambientais. O aumento destas monoculturas intensivas, bem como o incremento do cultivo de peixes carnívoros e de camarão, resultaram na utilização excessiva de recursos, na dependência de rações comerciais, bem como precipitaram o aumento de descargas de efluentes nas zonas costeiras. Com a atual tendência para o consumo de alimentos cultivados organicamente, provenientes de ambientes naturais não poluídos, uma aquacultura mais sustentável é, não só, desejável, como deverá ser o futuro a seguir pelo sector. […].info:eu-repo/semantics/publishedVersio

    Cultivo de macroalgas… Que futuro?

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    A secção Biologia é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. Nos Açores as macroalgas marinhas são tradicionalmente usadas na alimentação humana. No livro “Flora Marinha do Litoral dos Açores” publicado em 2005, os autores referem que a alga castanha Fucus spiralis, de nome comum “tremoço do mar”, é consumida como um petisco; a alga vermelha Porphyra, de nome comum “erva patinha”, é consumida frita e usada na confeção de sopas, omeletes ou tortas; as algas vermelhas Laurencia e Osmundea, de nome comum “erva malagueta”, são conservadas em vinagre e consumidas ao longo de todo o ano em algumas ilhas. Por outro lado, algumas espécies de macroalgas foram comercializadas até ao início da década de 1990. As algas vermelhas Pterocladiella capillacea e Gelidium microdon eram recolhidas manualmente ou por mergulho, posteriormente secas ao ar (era comum observar-se longos tapetes de algas a secar ao longo dos passeios em Vila Franca do Campo e em outras localidades) e preparadas para exportação, sendo depois utilizadas na produção industrial de agar. Num trabalho realizado nos anos 1980, solicitado pelo Governo Regional dos Açores, foram estudados vários aspetos sobre a apanha e a biologia desta alga agarófita Pterocladiella capillacea. Os dados da época, mostravam que nos Açores estavam a ser recolhidas 1800 toneladas (peso seco), o que representava 325 toneladas de agar de grande qualidade. […].info:eu-repo/semantics/publishedVersio

    Opportunities for Seaweed Aquaculture Development in the Azores

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    Jornadas "Ciência nos Açores – que futuro? Tema Ciências Naturais e Ambiente", Ponta Delgada, 7-8 de Junho de 2013.As macroalgas marinhas têm sido largamente usadas para diversos fins. Nos Açores, várias espécies têm sido usadas tradicionalmente na alimentação humana (e.g. Fucus spiralis, Porphyra spp., Laurencia spp. e Osmundea spp.) e para extracção de compostos com interesse na indústria dos ficocolóides (Pterocladiella capilacea e Gelidium spp.). As exigências no controlo da qualidade e as práticas actuais de colheita de macroalgas marinhas selvagens na Europa levantam preocupações ambientais sérias que tornam premente a necessidade se implementarem métodos de produção de biomassa controlados, como é o caso da aquacultura de macroalgas marinhas. Apesar da importância da exploração sustentável dos recursos marinhos existentes nos Açores, não existe informação sobre a viabilidade do cultivo de macroalgas marinhas no Arquipélago. O conhecimento sobre os requisitos básicos para o cultivo em grande escala das espécies nativas seleccionadas e os locais mais apropriados para a sua implementação está em falta. O objectivo principal do presente projecto é avaliar o potencial de cultivo de espécies de macroalgas marinhas seleccionadas, bem como identificar os métodos de cultivo mais adequados. Os resultados do programa de doutoramento serão de extrema importância quer em termos científicos quer em termos empresariais. Permitirão a transferência de tecnologia para o tecido empresarial regional e para a implementação de empresas de base tecnológica indo ao encontro das futuras políticas de financiamento europeias no âmbito do Programa Europeu Horizonte 2020.ABSTRACT: Seaweeds have a wide range of applications. In the Azores, several species of seaweeds were traditionally used either as food (e.g. Fucus spiralis, Porphyra spp., Laurencia spp. and Osmundea spp.) or for extraction of chemical products (Pterocladiella capilacea e Gelidium spp.). The product quality control requirements and concerns regarding the environmental sustainability of current wild seaweed biomass harvesting practices in Europe demand for controlled seaweed aquaculture. Despite the interest in exploiting Azorean seaweed resources, there is no information on the feasibility of cultivating seaweed in the Azores. Basic knowledge on large scale cultivation requirements of the selected native species is missing. The present project it’s aimed at evaluating the culture potential of selected Azorean species. The resulting outputs will be extremely important for both academic and economic purposes, bringing together the research and the market. Innovative enterprise will benefit from this project and develop technological breakthroughs into viable products with real commercial potential. This main objective is in according with the principal strategy of the Horizon 2020 that will tackle societal challenges after the end of FP7.Fundação para a Ciência e Tecnologi

    Short term effects of irradiance on the growth of Pterocladiella capillacea (Gelidiales, Rhodophyta)

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    Pterocladiella capillacea has been economically exploited for agar extraction in the Azores for many years. Harvesting dropped to a full stop in the early 1990s due to a population collapse, but restarted in 2013. Since then it has been intensively harvested and overexploitation must be prevented, with both sustainable harvesting and effective cultivation practices. This study represents the first attempt to determine optimal conditions for P. capillacea production in the Azores, and evaluates its vegetative growth in two experiments using von Stosch’s medium designed to test entire thallus and tips portions response to different irradiances (30, 70 and 150 μmol photons m¯² s¯¹). The best relative growth rate (RGR) was recorded at 150 μmol photons m¯² s¯¹ for the entire thalli and tips after two-weeks and three-weeks, respectively, indicating that an acclimation period is necessary to assure the growth of this alga under experimental conditions. Higher RGR was obtained at higher irradiance (3.98 ± 2.10% fm day¯¹), but overall, growth rates were low or negative. Epiphytes were a serious problem towards the end of the entire thallus experiments, where Feldmannia irregularis proliferate at all irradiances. Future cultivation approaches complemented with other relevant environmental factors (e.g. pH, photoperiod, salinity), are recommended.FCT – Fundação para a Ciência e Tecnologia projects UID/BIA/00329/2013, 2015 - 2018 and UID/BIA/00329/2019, CIRN (Centro de Investigação de Recursos Naturais, University of the Azores), and CIIMAR (Interdisciplinary Centre of Marine and Environmental Research, Porto, Portugal). RFP was supported by a doctoral grant M3.1.2/F/024/2011, Fundo Regional para a Ciência e Tecnologia.info:eu-repo/semantics/publishedVersio

    Effects of coastal orientation and depth on the distribution of subtidal benthic assemblages

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    Copyright © 2013 Blackwell Verlag GmbH.A better understanding of biological systems can only be gained if we understand what processes are important and how they operate to determine the distribution of organisms. Coastal orientation and depth can influence environmental conditions, including the degree of water motion and availability of light, which in turn may influence the horizontal and vertical patterns of organism distribution. Here, we used a mixed-model design to examine the effects of coastal orientation and depth on the structure of benthic assemblages by comparing the abundance and distribution of macroalgae and invertebrates in shallow and deep waters on the opposing coasts of Sa˜o Miguel. Generally, coastal orientation had little influence on the distribution of most taxa. In contrast, significant differences were generally associated with depth, although patterns were spatially variable at the scale of locations. This study suggests that depth, and processes operating at the scale of location, but not at the scale of the coast, have an important influence on these assemblages, and that failure to recognise such a scale of variability may hamper our ability to better understand the processes that structure these communities

    Growth responses of Macrocystis pyrifera (Laminariales), Southern Chile, juvenile sporophytes to nutrient limitation

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    1st Mares Conference on Marine Ecosystems Health and Conservation. Olhão, Portugal 17-21 November 2014.Kelp forests represent some of the most conspicuous coastal habitats and today we recognize only one giant kelp species (Macrocystis pyrifera) distributed globally [1, 2]. M. pyrifera is recognized as a perennial kelp species with a low capacity of energy storage, whereas its high productivity is associated the availability of nitrogen from the water column [3]. The relation between M. pyrifera growth and biomass production results from a plastic response of the sporophytes to temporal and spatial variability in nitrogen availability [4, 5]. However, the low storage capacity of giant kelp [6, 7] is clearly disadvantageous during periods of suboptimal environmental conditions; as those that occur seasonally in California and the inland waters of southern Chile. Due to an increased demand for kelp biomass in Chile for the world alginate industry and abalone farming in Chile [8, 9] there is an increased demand of raw material and interest for developing kelp aquaculture technologies [10]. The present study evaluates the effect of different nitrogen availability on the growth and regeneration of juvenile fronds of M. pyrifera sporophytes from southern Chile and explore its consequences for the development of seeding strategies of kelp farming in southern Chile

    Biotechnological applications of selected macroalgae

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    IBBA Strategic Planning - Workshop III, Plant Biotechnology Ponta Delgada, 25 Janeiro, 2011

    Nutritional value of selected macroalgae

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    Copyright © Springer Science+Business Media B.V. 2011.Macroalgae are traditionally used in human and animal nutrition. Their protein and fiber content have been widely studied and differ according to the species, their geographic origin and their seasonal conditions. In addition to their value for human nutrition, seaweeds have multiple therapeutically applications (e.g., weight control, hypocholesterolemic, antioxidant and antitumor activities, others) and, in general, contribute and promote human health. In the archipelago of the Azores, the consumption of seaweeds is widespread and accepted as a common practice in some islands. This work is aimed at providing information on the protein and fiber content of the locally consumed species, to promote this regional food product that can be potentially profitable from the biotechnology and commercial perspective, and also benefit public health, particularly, taking into account the low level of marine pollution in the Azores archipelago. Protein and fiber content of eight seaweeds (Porphyra sp., Osmundea pinnatifida, Pterocladiella capillacea, Sphaerococcus coronopifolius, and Gelidium microdon, Rhodophyta; Cystoseira abies-marina and Fucus spiralis, Phaeophyta; Ulva compressa, Chlorophyta) were determined using the Kjeldahl method and the Weende method, respectively. The protein content ranged from 6.81 to 26.62 of dry weight for C. abies-marina and U. compressa, respectively. Fiber content was generally higher as compared with that in seaweeds from other origins and ranged from 33.82 to 63.88 for O. pinnatifida and F. spiralis, respectively

    Antioxidant activity of macroalgae from the Azores

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    Free radical scavenging activity (FRSA) was studied to determine the antioxidant activity of 8 common macroalgae species found in the Azores. Species under study were Porphyra sp., Osmundea pinnatifida, Pterocladiella capillacea, Sphaerococcus coronopifolius and Gelidium microdon, from Rhodophyta; Ulva compressa and Chaetomorpha pachynema, from Chlorophyta and Fucus spiralis from Phaeophyta.The antioxidant activity was evaluated in methanolic extract by a decolourisation solution test of 2,2-diphenyl-1-picrylhydrazyl (DPPH), used as a stable radical. The methanolic extracts were obtained from dried biomass by sequential extractions, attaining a final concentration of 2 mg.mL-1. The FRSA values ranged from 19.54% for S. coronopifolius to 60.05% for F. spiralis with standard deviation (SD) varying between 1.41% and 6.80%. Results indicated that the studied seaweeds are a very promising source of biological active compounds with antioxidante properties. The seaweeds were collected in the Azorean islands where seawater pollution levels are low. Consequently, these seaweeds represent a valuable and good source of antioxidante material with superior beneficial effects on human health

    Índices para monitorização de qualidade ecológica de costas rochosas com base em comunidades de macroalgas : simplificação para utilização em áreas geográficas alargadas

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    Copyright © 2013 APRH.Este estudo centra-se em características de comunidades de macroalgas do intertidal rochoso para avaliação da qualidade ecológica das massas de águas costeiras no âmbito da Diretiva-Quadro da Água (DQA). É proposto um índice alternativo aos desenvolvidos nas Ilhas Britânicas, no norte da Espanha e em Portugal continental, que resulta da comparação da aplicação de todos os índices a um conjunto de dados recolhidos em praias açorianas, discutindo-se a adequação dos parâmetros utilizados em cada índice. Os parâmetros incluídos no índice proposto foram selecionados de forma a permitir a sua aplicação numa área geográfica alargada.ABSTRACT: This study focuses on intertidal rocky shore seaweed community features used for the assessment of ecological quality of coastal water bodies for the Water Framework Directive (WFD). An alternative index to those developed in the British Isles, in northern Spain and in mainland Portugal is proposed. Results from the application of all indices to a dataset collected on Azorean shores are compared and the suitability of the features used in each index discussed. The features included in the proposed index were selected to allow its applicability throughout a large geographic area
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