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- Estudo sobre a Caraterização da Apanha de Isco nos Principais Sistemas Estuarinos Nacionais e Caraterização da Atividade de Importação de Isco Vivo, no âmbito do projeto PROMAR – “Isco Vivo: Anelídeos Poliquetas Como Isco Vivo Em Portugal: Gestão da Apanha, Importação e Cultivo”Publication . Costa, José Lino; Canning-Clode, João; Castro, João; Cancela Da Fonseca, Luís; Chainho, Paula; Fidalgo, Pedro; Sá, Erica; Alves, Ana Sofia; Castro, Nuno; Mirra, Carla; Cabral, SaraEste documento constitui o Relatório final relativo à prestação de serviços para elaboração de um estudo sobre a “Caraterização da Apanha de Isco nos Principais Sistemas Estuarinos Nacionais e Caraterização da Atividade de Importação de Isco Vivo”, no âmbito do projeto “ISCO VIVO: Anelídeos Poliquetas como Isco Vivo em Portugal: Gestão da Apanha, Importação e Cultivo”, financiado pelo Programa PROMAR, com o Instituto Politécnico de Leiria como instituição proponente. O presente relatório consiste na descrição dos trabalhos desenvolvidos entre novembro de 2014 e dezembro de 2015 para cumprir as tarefas previstas nesse estudo sobre a “Caraterização da Apanha de Isco nos Principais Sistemas Estuarinos Nacionais e Caraterização da Atividade de Importação de Isco Vivo”. Estas incluíam: a) Caraterização da apanha de isco nos principais sistemas estuarinos portugueses; b) Caraterização da atividade de importação de isco vivo em Portugal; c) Determinação do impacto potencial da importação de isco vivo no país. Apresentam-se no documento os principais resultados obtidos após a aplicação da metodologia prevista na proposta de trabalho, que incluiu a realização de amostragens (observações no terreno e realização de inquéritos) nos quatro principais sistemas estuarinos portugueses: Ria de Aveiro, estuário do Tejo, estuário do Sado e Ria Formosa.
- The Lusitanian toadfish as bioindicator of estuarine sediment metal burden: The influence of gender and reproductive metabolismPublication . Pedro, Sílvia; Duarte, Bernardo; Castro, Nuno; Almeida, Pedro Raposo; Caçador, Isabel; Costa, José LinoEarly diagenetic processes and anthropogenic activities are responsible for metal enrichment in estuarine sediments. The Tagus estuary (Portugal) is no exception, and as a result of past and present pressures, surface sediment contamination is still an issue in some areas. Since such metal loads may be incorporated by benthic organisms, this study analyzed the accumulation of trace metals in the Lusitanian toadfish (Halobatrachus didactylus) in the Tagus estuary. In order to determine the role played by the seasonal reproductive cycle of the Lusitanian toadfish in the bioaccumulation process of trace metals in its tissues, the concentrations of Cd, Co, Cr, Cu, Ni, Pb and Zn were determined in the liver of male and female specimens captured during reproductive and non-reproductive periods. The results showed that metal accumulation in the liver was related simultaneously with gender and season, with females having higher levels of Cd, Cu and Zn during the reproductive period. The metabolic roles of Cu and Zn in embryonic development may explain such results, as both metals accumulated in the female liver to be transported to the gonads later on. Cd, on the other hand, does not have a metabolic role, and the higher concentrations of this metal found in spawning females could be related to the high affinity of Cd to vitellogenin, which is produced in the liver. To assess the species’ potential as an indicator of metal contamination, the concentrations of the seven elements were compared in the muscle tissue of adult, type I males (age ≥5), from two areas with distinct sediment metal loads. Non-essential metals in the muscle reflected the same differences between areas that were found in the sediment samples, evidencing H. didactylus as a potential indicator of those elements bioavailability from the sediment. The results showed that the muscle tissue of adult specimens of a relatively sedentary species such as H. didactylus is a useful indicator of long term accumulation of trace metals. On the contrary, liver concentrations of trace metals showed variation according to the reproductive status, which could lead to overestimate of the environmental status concerning trace metals bioavailability. Spawning season and liver tissue should thus be avoided in biomonitoring studies targeting this benthic fish.
- Trade of live bait in Portugal and risks of introduction of non-indigenous species associated to importationPublication . Sá, Erica; Fidalgo E Costa, Pedro; Cancela Da Fonseca, Luís; Alves, Ana; Castro, Nuno; Cabral, Sara; Chainho, Paula; Canning Clode, João; Melo, Pedro; Pombo, Ana; Costa, José LinoDifferent invertebrate groups are often exploited on sediment shores and mudflats, including polychaetes, sipunculids, bivalves and crustaceans. The commercial importance of polychaetes and sipunculids, that has increased in the early 2000's because of its use as a food source for the aquaculture sector and a growing demand of worms for use as sea angling bait, seems to be declining nowadays. In Portugal bait harvesting from natural populations became insufficient to meet market demands and as a result, polychaetes and sipunculids have been imported in recent years. Due to this it was important to know the ways of the live bait import to Portugal, and to assess the risk of introduction of non-indigenous species associated to that live bait trade. The origin and quantities of imported live bait were determined by examining the landing's records at Lisbon airport, from two periods: 2002-2003 and 2012-2015. Live worms imported to Portugal arrived almost exclusively from China, USA and Vietnam. Monthly import data and bait registers at fish auction landings were significantly correlated, showing that bait captures and imports are directly related to higher bait demand. In addition, the risk of live bait's importation as an introduction vector for non-indigenous species was evaluated by examining the bait boxes content. Five worm species were identified in bait boxes with foreign species: Glycera dibranchiata, Namalycastis rhodochorde, Perinereis cultrifera, Perinereis linea, and Sipunculus (Sipunculus) nudus. The examination of bait boxes in Portugal suggested that there is a low risk of associated hitchhiker species introduction and dissemination, mostly because of packaging procedures, which should be advised. The same is not true to the non-indigenous live bait species.
- Fish communities’ response to implementation of restoring measures in a highly artificialized estuaryPublication . Castro, Nuno; M. Félix, Pedro; Neto, João; Cabral, Henrique; Marques, João Carlos; Costa, Maria José; Costa, José LinoOver the years, the Mondego estuary has undergone various anthropogenic impacts. One of the most serious was the closing of the communication between the two arms of the system (north and south), in the 1990s, which promoted eutrophication and a consequent water quality decline in the south arm. Several mitigation measures were subsequently implemented, in particular the re-establishing of the communication between the two arms in 2006, increasing water flow and reducing water residence time in the south arm. The present study aimed to evaluate the impact of management measures on the ecological and conservation condition of the Mondego estuary, through a longitudinal assessment of the structure and composition of the fish communities over a decade. The Mondego fish community showed important modifications over the years, in terms of structure, ecological quality and conservation value. The fish community status improved following the reconnection of both arms. In the south arm those changes appear to be more evident than in the other estuarine areas, where an inverse pattern was observed in the last few years. A redistribution of the fish species within the system may have been responsible for those unexpected alterations in the north arm and upstream area.
- Movements of Diplodus sargus (Sparidae) within a Portuguese coastal Marine Protected Area: Are they really protected?Publication . Belo, Ana Filipa; Pereira, Tadeu; Quintella, Bernardo; Castro, Nuno; Costa, José Lino; Almeida, Pedro Raposo deMark-recapture tagging and acoustic telemetry were used to study the movements of Diplodus sargus within the Pessegueiro Island no-take Marine Protected Area (MPA), (Portugal) and assess its size adequacy for this species' protection against fishing activities. Therefore, 894 Diplodus sargus were captured and marked with conventional plastic t-bar tags. At the same time, 19 D. sargus were tagged with acoustic transmitters and monitored by 20 automatic acoustic receivers inside the no-take MPA for 60 days. Recapture rate of conventionally tagged specimens was 3.47%, most occurring during subsequent marking campaigns. One individual however was recaptured by recreational fishermen near Faro (ca. 250 km from the tagging location) 6 months after release. Furthermore, three specimens were recaptured in October 2013 near releasing site, one year after being tagged. Regarding acoustic telemetry, 18 specimens were detected by the receivers during most of the study period. To analyse no-take MPA use, the study site was divided into five areas reflecting habitat characteristics, three of which were frequently used by the tagged fish: Exterior, Interior Protected and Interior Exposed areas. Information on no-take protected area use was also analysed according to diel and tidal patterns. Preferred passageways and permanence areas were identified and high site fidelity was confirmed. The interaction between tide and time of day influenced space use patterns, with higher and more variable movements during daytime and neap tides. This no-take MPA proved to be an important refuge and feeding area for this species, encompassing most of the home ranges of tagged specimens. Therefore, it is likely that this no-take MPA is of adequate size to protect D. sargus against fishing activities, thus contributing to its sustainable management in the region.
- Changes in trophic ecology of fish assemblages after no take Marine Protected Area designation in the southwestern coast of PortugalPublication . Pereira, Tadeu José; Manique, Joana; Quintella, Bernardo; Castro, Nuno; Almeida, Pedro Raposo de; Costa, José LinoChanges in fish assemblage structure caused by human activities, such as fishing, can alter trophic relations in fish assemblages. In this context, Marine Protected Areas (MPA) are efficient tools for habitat recovery and ideal environments for evaluating changes on the trophic structure resulting from human activities. The present work targeted fish assemblages from two no-take MPAs from the northern half of South Alentejo and Costa Vicentina Marine Park, established in 2011. Previous works reported positive effects on local fish assemblages after no-take MPA designation, and it is therefore important to further study its impact on local fish assemblages, especially concerning trophic interactions. Local fish assemblages were sampled (summer 2011, winter 2012, summer 2013 and winter 2013) using trammel nets. Diets were characterized and digestive tract contents of the 10 most abundant fish species were compared between the no take MPAs (treatment) and adjacent areas (controls), and changes evaluated as a function of time since protection. Results revealed significant differences between the diets of fish from protected and non protected areas, with crabs being the preferential prey in both protected and control areas but being more ingested outside the no-take areas. However, these differences were evident since the beginning of the study. Fish assemblages from the northern area presented significantly larger niche breadth and significantly increasing with time. This way, the main effects of no-take MPA implementation were directly visible on the niche breadth but did not directly impact the diet composition of the sampled fish assemblages, contributing however to reinforce the already naturally existent differences. This work provides important information regarding the effect of changes in the fish assemblage caused by MPA designation on the trophic ecology of fish.
- Marine invasions in a warming Macaronesia : understanding diversity and connectivity patterns through field, laboratory and analytical studiesPublication . Castro, Nuno; Canning-Clode, João; Costa, José Lino; Gestoso, IgnacioThe introduction of Non-Indigenous Species (NIS) is a global phenomenon with devastating consequences for biodiversity, ecosystem services, and human well-being. This thesis aims to unravel the complexities of NIS dynamics, offering insights into their effects and increasing the comprehensive understanding of these crucial ecological phenomena within the context of climate change in the marine environment of Macaronesia. The thesis is divided into four chapters, each addressing specific facets of the NIS issue. The first section briefly introduces invasion ecology in a marine Macaronesian context. The first Chapter provides a comprehensive inventory of NNS (Non-Native Species) in Macaronesia, highlighting the influence of various factors, including maritime traffic, on NNS presence. This pioneering study reveals the region's baseline number of NNS, with variations among different archipelagos. It features the critical role of marine traffic and infrastructure in hosting NNS. Chapter Two explores the role of maritime traffic as a primary vector for NIS introduction in Madeira. It identifies invasion corridors by analyzing significant traffic routes and underscores the importance of understanding these corridors for NIS management. Chapter three delves into propagule pressure and barriers for NIS establishment and proliferation. This Chapter is divided into three segments. First, it investigates how maritime traffic intensity and artificial structures influence fouling assemblages and demonstrates the impact of recreational boating in NIS dispersion. In the second part of this Chapter, a detailed study of NIS in Macaronesia is conducted to detect variations in NIS numbers, abundance, and recruitment. Abiotic factors like temperature and latitude and biotic elements such as species richness and competition are analysed. The findings partially confirmed a latitudinal trend, with lower latitudes showing lower NIS recruitment and NIS percentage cover. The final segment of Chapter Four examines the impacts of Marine Heat Waves (MHWs), exacerbated by global warming, on Native and NIS in a marine environment. The study showed that longer and more intense MHWs events had an overall negative impact, affected the invasibility of sessile assemblages and encouraged more adapted species to thrive. Chapter Five focuses on the NIS management aspect, assessing the invasion risk of a tropical fish species that arrived in Madeira due to climate change. Finally, the general discussion evidences the absence of NIS biosecurity or management protocols in Macaronesia, emphasizing the need for preventive measures to tackle NIS. In conclusion, this research constitutes a vital milestone in comprehending the ecology of marine biological invasions in Macaronesia and advancing efforts to prevent, manage, and respond to the evergrowing threat of NIS in a rapidly changing world.
- Changes in fish assemblage structure after implementation of Marine Protected Areas in the south western coast of PortugalPublication . Pereira, Tadeu José; Manique, Joana; Quintella, Bernardo; Castro, Nuno; Almeida, Pedro Raposo de; Costa, José LinoMarine Protected Areas (MPAs) are increasingly being recommended as management tools for biodiversity conservation and fisheries. With the purpose of protecting the region's biodiversity and prevent the over exploitation of marine resources, in February 2011 the no-take MPAs of Ilha do Pessegueiro and Cabo Sardão were implemented within the "Parque Natural do Sudoeste Alentejano e Costa Vicentina" (PNSACV) Marine Park, south western coast of Portugal. As such, commercial and recreational fishing became prohibited in these areas. In order to evaluate the effects of these no-take MPAs, the structure of their fish assemblages and of adjacent control areas without fishing restrictions were studied between 2011 (immediately after implementation) and 2013 (two years after implementation). A total of 4 sampling campaigns were conducted (summer 2011, winter 2012, summer 2013 and winter 2013) using trammel nets and bottom trawl. Ichthyofaunal assemblages from the no-take MPAs (treatment) were compared with adjacent areas (controls) and changes evaluated as a function of time since protection. Results revealed significant increase in fish abundance after the implementation of the no-take MPAs. Furthermore, significant differences in the structure of fish assemblages (abundance and fish size) between protected and neighbouring areas were rapidly observed upon the implementation of the no-take MPAs. In addition, specimens of larger size occurred more frequently within Ilha do Pessegueiro no-take MPA in the last year of the study. Overall, despite the young age of these no-take MPAs, changes on the structure of their fish assemblages were already evident after only two years of protection, indicating that management measures such as MPA designation may play an important role to promote fisheries sustainable exploitation as well as to protect species with conservation interest.