Browsing by Author "Soares, Florbela"
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- AQUACULTURA MULTI-TRÓFICA INTEGRADA EM TANQUES DE TERRAPublication . Maria Emília Cunha; Quental-Ferreira, Hugo; Ribeiro, Laura; Moreira, Márcio; Soares, Florbela; Caetano, Miguel; Ferreira, Pedro Pousão; Instituto Português do Mar e da Atmosfera, I.P.Integrated multi-trophic aquaculture (IMTA) is the combined cultivation of animals that need food from external origins together with organisms that extract organic and inorganic matter from the rearing environment creating a balanced production system. This paper presents the results obtained during the first year of an integrated multi-trophic production of gilthead sea bream (Sparus aurata) and several sea-breams species (Diplodus sargus, D. cervinus, D. puntazzo, and D. vulgaris), Portuguese oyster (Crassostrea angulata) and a sea cucumber (Holothuria mammata) grown in earthen ponds in order to evaluate the adaptability of these species to integrated cultivation, their growth performance and the most suitable structures for oyster farming in ponds. Animal biomass produced per cubic meter per tank at the end of this experiment were respectively 0.4 kg and 0.6 kg in simple polyculture and multi-trophic polyculture. It was observed in tanks of simple polyculture that the concentrations of nitrate + nitrite and phosphate were higher comparatively to the multi-trophic polyculture that showed higher values of chlorophyll a, and total organic carbon and total organic nitrogen. Oysters daily growth rates varied between 10.3% and 7.2% and were higher during the summer - autumn when mortality was also higher. The microbiological quality of the oysters in the rearing tanks was better than the neighboring oyster beds at Ria Formosa coastal lagoon from where the water comes from suggesting the existence of an intermediate purification process of the inlet water. From the tested oysters farming structures, the suspended lanterns showed better results in terms of survival. The fish species showing better adaptation to growth in earthen ponds were Sparus aurata and Diplodus cervinus. D. cervinus seemed to be better adapted (growth and survival) to multitrophic integration.The external parasites that affect the fish gills were Microcotyle and Lamellodiscus and there were no differences in prevalence and/or incidence between the two rearing systems. Lamellodiscus affected the larger fish and Microcotylethe smaller ones. In the rearing conditions of the experiment sea cucumbers had very low survival.
- PRODUÇÃO DE LARVAS E JUVENIS DE OURIÇOS-DO-MAR (Paracentrotus lividus) NA ESTAÇÃO PILOTO DE PISCICULTURA DE OLHÃO (EPPO)Publication . Mendes, Ana Candeias; Araújo, João; Soares, Florbela; Pousão-Ferreira, Pedro; Instituto Português do Mar e da AtmosferaThe sea urchin is a marine resource with increasing demand and commercial value, mainly in the international markets. The interest for this species comes mainly from their gonads (roe) reaching very high prices due to its value as a product of gourmet cuisine. Due to the growing demand and consequent capture a decrease of the natural stocks has been observed. The sustainable consumption of this resource requires the development of aquaculture production satisfying the international market. Production trials of sea urchins (Paracentrotus lividus) at IPMA started using breeders captured off the Algarve coast in 2016 and conditioned in EPPO facilities - Aquaculture Research Station of Olhão, fed with macroalgae Ulva spp. and corn grain (Zea mays). Spawning induction was obtained by injection of magnesium chloride 0.5 M in the celomic space by the peristomial membrane. Fertilization and embryonic development were accompanied by microscope observation. During the planctonic stage the sea urchins larvae were fed with a mixture of different microalgae in order to assure the nutritional requirements. A survival rate of 30% was observed at 15DAE (days after hatch). At age 27DAE metamorphosis and fixation was verified. After reaching the benthic stage the sea urchins were fed with the same mixture of microalgae plus macroalgae Ulva spp. After 4 months of age sea urchins were fed exclusively with macroalgae and macroalgae and corn. At 7 months of age (221DAE) sea urchins fed with macroalgae showed a higher somatic growth (test diameter), however individuals fed with seaweed and corn had a better GSI (gondosomatic index).