ESTM - Mestrado em Aquacultura
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- Nutritional tools to enhance the resilience to stress and diseases of the whiteleg shrimp Penaeus vannameiPublication . Andrade, Flávio André Monteiro; Baptista, Teresa Maria Coelho; Barreto, André BarretoThe Pacific white shrimp (Penaeus vannamei) is currently one of the most widely farmed aquaculture species. Industry faces challenges related to diseases and environmental fluctuations, which compromise productivity and sustainability. Since shrimp cannot be vaccinated, due to the lack of acquired immunity, and the use of antibiotics in aquaculture is increasingly restricted, immunomodulation through nutrition emerges as a viable alternative. This study evaluated the potential of supplementing diets with extracts derived from Salicornia ramosissima for juvenile P. vannamei, testing their ability to enhance resilience to extreme farming conditions, such as acute and chronic stress induced by air exposure. Five diets were formulated: one control and four supplemented with 0.1% and 0.5% inclusions of XAD and Ext3 extracts. Shrimps were fed the experimental diets for 29 days under normal and chronic stress conditions, followed by an acute stress challenge in the groups reared under normal conditions. Zootechnical parameters, survival after acute stress, and immunological and antioxidant biomarkers were analysed. Results showed that, in general, the extracts did not compromise growth or survival, except for the Ext3 at 0.1% treatment, which exhibited higher FCR. The stress methodologies effectively induced physiological responses, with differences in biomarkers between control and stressed groups. Although no clear effects were observed under chronic stress, some indications of a protective effect of the extracts were noted under acute stress, but these were not confirmed by mortality data. In conclusion, supplementation with S. ramosissima extracts did not impair shrimp performance and revealed promising trends that justify further investigation.
- Avaliação de parâmetros de cultivo de Lysmata debelius Bruce, 1983 ao longo do desenvolvimento larvar e juvenilPublication . Salgado, Daniel Francisco; Leandro, Sérgio Miguel Franco Martins; Marques, Sónia Cristina FerreiraA presente dissertação teve como principal objetivo completar o ciclo de vida do camarão-de-fogo, de Lysmata debelius Bruce, 1983, em condições controladas de cativeiro, contribuindo para a sua domesticação e para o avanço da aquacultura ornamental. Para tal, foram definidos três eixos centrais de investigação: determinar o período até à obtenção de indivíduos com tamanho comercial, avaliar a influência da densidade de cultivo e da luz LED azul e branco (azul: 450-470nm e branco: 450-700nm) na sobrevivência e no assentamento larvar. Estes fatores são considerados determinantes para a definição de protocolos de cultivo eficientes e sustentáveis. Os resultados demonstraram que a sobrevivência larvar de Lysmata debelius foi fortemente influenciada pela densidade de cultivo, com melhores valores registados nas densidades mais baixas (90–140 larvas L-1. A taxa de assentamento não revelou diferenças estatisticamente significativas entre tratamentos. O tempo até ao primeiro assentamento foi mais curto nos ensaios sem luz (81,67 ± 2,31 dias), em comparação com aqueles conduzidos sob luz LED azul e branco (89,67–93,33 dias), embora sem diferenças estatisticamente significativas. Por outro lado, o tempo médio total até ao assentamento mostrou diferenças estatisticamente significativas na ausência de luz, situando-se entre 86,67 e 91,18 dias, face a 93,50–96,82 dias em presença de luz, sem efeito relevante da densidade. Finalmente, ao integrar as fases larvar e juvenil, estimou-se que o período total desde a desova até às dimensões do tamanho comercial (3 cm), variou entre 194 e 202 dias. Estes resultados, fornecem uma base sólida para a compreensão da biologia larvar de L. debelius, fundamental para a otimização dos protocolos de cultivo desta espécie e reforçam a necessidade de considerar múltiplos fatores ambientais e de manejo no desenho de sistemas produtivos. Do ponto de vista prático, esta investigação confirmou a viabilidade da produção sustentável desta espécie, abrindo caminho para reduzir a pressão sobre populações selvagens e responder à crescente procura do mercado. A consolidação de protocolos larvares e reprodutivos representa um passo essencial para a expansão da aquacultura ornamental, promovendo práticas mais responsáveis e ambientalmente sustentáveis, resultando numa menor dependência de exemplares capturados em populações naturais. Em forma conclusiva, este trabalho estabelece as bases para o cultivo controlado de Lysmata debelius, representando um contributo científico e aplicado relevante para a sua domesticação e para a consolidação da aquacultura ornamental como setor sustentável e inovador.
- Curricular Internship at SeaweedlandPublication . Pereira, Paulo Alexandre Portela; Baptista , Teresa Maria CoelhoThis internship focused on the cultivation, monitoring, and experimental optimization of macroalgae species, namely Ulva spp., Palmaria palmata, and Gracilaria spp., in land based aquaculture systems in the Netherlands. Activities were centered on raceways and large-capacity tanks, where both production and research tasks were conducted. The internship has included several trials to test variables such as temperature, light regimes, biomass densities, and nutrient formulations. Based on these results, cultivation protocols were scaled up from laboratory to production systems. Weekly biomass sampling, macroscopic quality assessments, and growth rate analyses (DGR%) were performed, with efforts made to maintain ideal cultivation densities and harvest the surplus biomass for drying and commercialization. Key contributions during the internship included the development and application of customized nutrient solutions; the management of environmental challenges such as seasonal variations in light and temperature, which triggered events like Ulva sporulation or growth decline in Palmaria palmata. These challenges were addressed through strategies like artificial lighting, temperature regulation, and customized fertilization schedules. Contamination control protocols were implemented, involving the selection and cleaning of Gracilaria spp., removal of epiphytes, and incubation under controlled conditions. Additional activities included participation in innovative seeding techniques such as direct seeding of Saccharina latissima, as well as tagging trials for monitoring the growth of Palmaria palmata individuals. The technical infrastructure was also a focus, with the installation and maintenance of filtration systems, aeration equipment, light setups, and environmental sensors for monitoring pH, salinity, turbidity, and temperature. To conclude, this internship was fundamental to deep my understanding of phycology and in developing practical skills related to the design, management, and optimization of land based cultivation systems specifically adapted for macroalgae production.
- Internship Report at Oceano FrescoPublication . Baptista, Tiago Miguel Paiva; Baptista, Teresa Maria CoelhoThis internship report, developed over a one-year period from June 19, 2023, to June 19, 2024, documents the operational workflow and improvement opportunities identified in a commercial bivalve hatchery, with emphasis on Ruditapes decussatus and Venerupis corrugata. The internship covered all production stages, from broodstock conditioning to larval, post-larval, and seed rearing, providing a comprehensive understanding of hatchery routines and biosecurity practices. Daily, weekly, and monthly operations were followed in detail across each production unit, consolidating technical skills in husbandry, feeding, monitoring, and microbiological control. A central component of the internship was a pilot project addressing one of the most pressing bottlenecks the hatchery was facing at this period: the shortage of microalgae for feeding. Spare 3000 L seed tanks were repurposed for large-volume batch production of diatoms. Over successive production cycles, different configurations were tested, adjusting working volume, nutrient dosages, aeration systems, CO₂ supplementation, and lighting. Results demonstrated that aeration efficiency, nutrient balance, and carbon regulation are critical for sustaining high cell densities and culture stability. The introduction of CO₂ markedly improved performance, and batch-to-batch inoculation proved feasible, improving efficiency of operations and reducing dependence on the Upright Bag room. By the end of the project, daily harvests of several thousand liters of clean culture were achieved, significantly alleviating the feed shortage and supporting hatchery production. The internship also highlighted areas for further optimization, including broodstock quarantine and gonadal monitoring, continuous larval water quality monitoring, optimization of setting system configurations in the post-larval room, refinement of seed feeding and shipment protocols, and reinforcement of hygiene practices across transversal operations. A cross-cutting improvement identified was the digitalization of operational records, which would enhance traceability and predictive capacity. In conclusion, the internship achieved its dual aim: consolidating technical and scientific skills through full integration into hatchery operations, and successfully achieving the project through an industrial-scale trial that evolved into a viable production strategy. The experience provided not only practical expertise but also insights into the potential for continuous improvement and innovation in bivalve aquaculture.
- Estudo do comportamento do Rascasso da Madeira (Scorpaena maderensis) e avaliação do potencial ornamentalPublication . Mota, Mateus Manuel Silva Teles Neto da; Baptista, Teresa Maria Coelho; Correia, , João Pedro SantosA aquariofilia, enquanto atividade recreativa, tem crescido significativamente nos últimos anos, acompanhada por uma procura crescente por novas espécies ornamentais, a fim de oferecer uma maior variedade de opções aos consumidores. Dado o elevado custo das espécies ornamentais tropicais, a introdução de espécies de águas temperadas ou frias no mercado pode representar uma alternativa mais acessível. O presente estudo teve como objetivo investigar a espécie Scorpaena maderensis (Rascasso da Madeira) quanto à sua adaptação a ambientes aquáticos artificiais e ao seu comportamento, com a finalidade de avaliar o seu potencial como espécie ornamental. Problemas relacionados com a manutenção da qualidade da água resultaram em elevadas taxas de mortalidade. Contudo, foram obtidas informações promissoras sobre a capacidade de adaptação da espécie a aquários. S. maderensis, demonstrou um comportamento territorial, mas pode coexistir com outras espécies, desde que estas sejam de tamanho suficiente para não serem interpretadas como presas. A compatibilidade com outras espécies, a adaptação ao fornecimento de alimento não vivo e a aprendizagem de que a presença humana não representa uma ameaça são resultados positivos que indicam o potencial da espécie para ser estabelecida como uma espécie ornamental. Estudos futuros, conduzidos em aquários de maior porte, com manutenção aprimorada da qualidade da água e a introdução de diferentes espécies, poderão consolidar Scorpaena maderensis como uma opção viável para aquários ornamentais, além de proporcionar novos dados científicos sobre uma espécie ainda pouco estudada.
- Modelling Paracentrotus lividus (Lamarck, 1816) reproduction through nutrition and temperaturePublication . Santos, Patrícia Alexandra Matos; Lourenço, Silvia Alexandra PereiraThe sea urchin Paracentrotus lividus is highly appreciated in Europe for its gonads. The reddish-orange pigmentation of the gonads is the result of the accumulation of echinenone, a carotenoid pigment, resulting of the transformation, in the digestive tube, of dietary β-carotene present in a variety of algae which P. lividus feeds on. These carotenoids play a significant role in various biological functions of sea urchins, including oocyte production and development. Temperature has also been shown to influence the progression of sea urchins through their developmental stages and elevated temperatures have been demonstrated to exert a considerable degree of stress on the animals. The present study was conducted following the hypothesis that a diet abundant in carotenoids will have a beneficial effect on the reproduction and early development of sea urchins. The principal objective of this study was to evaluate the combined effect of different temperatures and diets on the maturity, oocyte size and embryonic development of P. lividus. To achieve such objective, adult sea urchins were subjected to a maturity enhancement trial of 120 days, where these were fed two jellified diets, one rich in carotenoids (HC) and the other without (LC). During the trial, the sea urchins were conditioned to two different temperatures, an ambient temperature (18ºC) and an ocean warming scenario (21.5ºC), in a crossed design with four conditioning treatments (18LC, 18HC, 21LC and 21HC). After this trial, the females from each treatment were induced to spawn, crossing their oocytes with the males from the 18HC treatment. The resulting eggs were then incubated for 48 hours at the same temperature as the females. The results obtained demonstrated a general increase in the gonadosomatic index in all treatments. Histological analysis showed that males had a higher percentage of maturation regardless of the conditioning treatment. Furthermore, the oocytes from the 18LC females were found to be larger than those produced by females from the remaining treatments. The embryos obtained from females of the 21HC treatment demonstrated accelerated development, with malformations affecting the position/shape of the spicules. The study concluded that all four treatments promoted maturation, partially supporting the initial hypothesis. It was also concluded that temperature at which the progeny is kept can have a greater influence on malformations than the diet consumed by the progeny, not supporting the initial hypothesis proposed.
- Internship Report at Oceano FrescoPublication . Vicente, Rúben Mckie; Baptista, Teresa Maria CoelhoThe increasing global demand for sustainable protein sources has positioned aquaculture as a key solution for food security and environmental conservation. This internship at Oceano Fresco focused on the cultivation of the native European clam species Venerupis corrugata and Ruditapes decussatus using innovative aquaculture techniques. The internship involved hands-on participation in hatchery operations, including broodstock handling, spawning, larval rearing, and microalgae cultivation, along with microbiological monitoring and biosecurity measures. Additionally, a research project was conducted to evaluate the impact of different conditioning methods on broodstock gonadal maturation and reproductive success. Results showed that broodstock conditioned in a recirculating system (R) exhibited 43.8% higher egg production, a 15.3 percentage point increase in hatching success, and nearly double the number of viable D-larvae compared to those in a flow-through system (FT). Despite no significant differences in broodstock survival or gonadal maturation rates between treatments, the R system facilitated faster reproductive development and improved larval viability. These findings highlight the potential of optimized conditioning protocols to enhance hatchery efficiency and contribute to the sustainable production of bivalves. Implementing such strategies could increase the availability of broodstock year-round, fostering greater independence from natural reproductive cycles and enabling continuous cultivation throughout the year.
- Passive immunisation of European seabass (Dicentrarchus labrax) against Nervous Necrosis Virus (NNV)Publication . Abrantes, Catarina Rebelo; Baptista, Teresa Maria CoelhoViral infections in aquaculture are one of the main obstacles to aquaculture development, as they cause high economic losses. Viral encephalopathy and retinopathy (VER), caused by nervous necrosis virus (NNV), significantly impacts marine and freshwater aquaculture, causing high mortality in larval and juvenile populations with mortality rates up to 100%. There is no effective treatment against this infection nor commercial vaccine development. This study aimed to assess the applicability of a polyclonal antibody with antiviral potential for supplementing the diet of European seabass (Dicentrarchus labrax) in the larval stage after contact with NNV of the RGNNV genotype, as well as to evaluate how this antibody treatment could influence both fish survival rates and the reduction of viral replication over time. A neutralisation protocol was established using rabbit anti-NNV polyclonal antibodies as a positive control. Results demonstrate that PAb can be effectively administered to fish through both immersion and dietary routes, with findings suggesting potential protective effects when delivered via the diet. It was found that NNV infection is more efficient via injection (20%) compared to immersion (0%). Mortality was monitored and analysed throughout the trial, along with viral load, to gain a comprehensive understanding of the potential benefits associated with the administration of this polyclonal antibody following NNV infection. A reduction in mortality was observed in the treatment in which the feed was supplemented with rabbit serum (33.2%) compared to the treatment where the fish were infected with NNV (41.7%). A reduction in viral load was also observed between these treatments. Thus, supplementation with antiviral immunostimulants could be a promising strategy to prevent irreversible damage. However, more studies are still needed to understand how the immune system works in the presence of NNV with subsequent supplementation with polyclonal antibodies.
- Avaliação ambiental e nutricional do ciclo de vida da spirulina em modo de produção artesanalPublication . Dias, Jéssica Cristina Nobre; Lourenço, Sílvia Alexandra PereiraA Avaliação do Ciclo de Vida (ACV) é uma metodologia que quantifica os impactos ambientais de um sistema ou de um produto. Pode ser aplicada na aquacultura em geral, assim como no cultivo de spirulina, auxiliando na tomada de decisões para reduzir os impactos causados. O presente estudo teve como objetivos fazer uma avaliação ambiental da produção artesanal de spirulina e comparar com um cenário de produção com certificação biológica, fazendo uma avaliação da sua composição nutricional, de forma a perceber qual das produções seria mais vantajosa a nível ambiental. Para a ACV foi elaborado um inventário do ciclo de vida com os recursos e processos utilizados na produção artesanal de spirulina produzida entre os meses de abril e outubro, na unidade de produção da Tomar Natural. A abordagem utilizada foi desde o início da produção até à fase do embalamento, e a unidade funcional foi definida como 1 kg de spirulina. A avaliação dos impactes foi feita com o programa SimaPro utilizando o método ReCiPe. Para o perfil bioquímico foi feita a quantificação da humidade e das cinzas, e a determinação da gordura total, perfil de ácidos gordos e conteúdo em proteína. Os resultados da ACV da produção artesanal obtiveram os maiores impactos na maioria das categorias de impacte associados à infraestrutura, energia e em terceiro lugar, a embalagem; o elevado impacto da infraestrutura pode estar ligado à produção dos materiais usados na construção da unidade de produção, mas também ao facto da contribuição dos restantes fatores ser relativamente baixa. Na produção biológica os maiores impactos foram: a infraestrutura para a ecotoxicidade terrestre e a energia nas alterações climáticas. Ao comparar os dois modos de produção, a biológica apresentou maiores impactos ambientais, principalmente no consumo da água, eutrofização de água doce e alterações climáticas. Na produção artesanal a água do cultivo e os nutrientes são reciclados, enquanto que na biológica o uso da ureia certificada como fonte de azoto gera muitos resíduos, fazendo com água seja renovada com maior frequência, e consequentemente há um maior consumo energético. Os resultados mostraram que a produção biológica obteve maiores impactos ambientais e maiores custos de produção. Os resultados da análise nutricional demostraram diferenças significativas no conteúdo lipidico e proteíco, enquanto que o perfil de ácidos gordos é semelhante entre os dois modos de produção. Os PUFA (ácidos gordos polinsaturados), de forma geral, constituem a maioria dos lípidos totais, reforçando a ideia de que a spirulina é uma excelente fonte de ácidos gordos. A diferença no perfil bioquímico varia de acordo com a temperatura de cultivo e de secagem, intensidade da luz, nutrientes, modo de produção e o momento da colheita. No caso da produção artesanal, o cultivo é feito em raceways onde podem ocorrer oscilações da temperatura, afetando a eficiência na produção de proteína e diminuir o conteúdo proteico do produto final. A baixa percentagem de proteína na spirulina artesanal pode estar relacionada com o método de extração utilizado ou o processo da produção do pó para as análises.
- Study of the potential of the macroalgae Halopteris scoparia in aquaculture productionPublication . Abreu, Márcia Perestrelo; Mouga, Teresa Margarida Lopes da Silva; Pombo, Ana Margarida Paulino ViolanteThis thesis explored the cultivation conditions and growth patterns of Halopteris scoparia under controlled laboratory settings, with the goal of optimizing its growth for potential use in Integrated Multi-Trophic Aquaculture (IMTA) systems alongside marine fish. Healthy, wild thalli of H. scoparia were collected, acclimated, and subjected to various experiments to assess the effects of different culture media, salinity levels, stocking densities, light conditions, temperature, and wastewater reuse. Throughout the trials, it was observed that these factors significantly influenced the key growth parameters, Relative Growth Rate (RGR) and productivity, of H. scoparia. Notably, the introduction of the commercial medium Nutribloom® led to a significant increase in growth rates. The macroalgae presented adaptability to different salinities and an optimal growth with lower stocking densities (1g/L). The use of white LED light also enhanced growth performance, while temperature trials did not yield conclusive results. Furthermore, H. scoparia demonstrated positive growth when cultivated in wastewater from a meagre (Argyrosomus regius) fish farm using a recirculating aquaculture system (RAS), both in full-strength and diluted forms. Analysis of the cultivated biomass revealed notable differences in humidity and ash content compared to wild specimens, underscoring the influence of cultivation conditions on seaweed composition. Overall, the study highlights the species' potential for rapid growth in aquaculture and its suitability for integration into IMTA systems.