Browsing by Author "Bueno-Pardo, Juan"
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- Climate change vulnerability assessment of the main marine commercial fish and invertebrates of PortugalPublication . Bueno-Pardo, Juan; Nobre, Daniela; Monteiro, J. N.; Sousa, Pedro M.; Costa, Eudriano; Baptista, Vânia; Ovelheiro, Andreia; Vieira, Vasco; Chicharo, Luis; Gaspar, Miguel; Erzini, Karim; Kay, Susana; Queiroga, Henrique; Teodosio, Maria; Leitão, FranciscoThis is the first attempt to apply an expert-based ecological vulnerability assessment of the effects of climate change on the main marine resources of Portugal. The vulnerability, exposure, sensitivity, adaptive capacity, and expected directional effects of 74 species of fish and invertebrates of commercial interest is estimated based on criteria related to their life-history and level of conservation or exploitation. This analysis is performed separately for three regions of Portugal and two scenarios of climate change (RCP 4.5 and RCP 8.5). To do that, the fourth assessment report IPCC framework for vulnerability assessments was coupled to the outputs of a physical-biogeochemical model allowing to weight the exposure of the species by the expected variability of the environmental variables in the future. The highest vulnerabilities were found for some migratory and elasmobranch species, although overall vulnerability scores were low probably due to the high adaptive capacity of species from temperate ecosystems. Among regions, the highest average vulnerability was estimated for the species in the Central region while higher vulnerabilities were identified under climate change scenario RCP 8.5 in the three regions, due to higher expected climatic variability. This work establishes the basis for the assessment of the vulnerability of the human activities relying on marine resources in the context of climate change.
- Eco-socio-economic vulnerability assessment of Portuguese fisheries to climate changePublication . Pinto, Miguel; Albo-Puigserver, Maria; Bueno-Pardo, Juan; N. Monteiro, J.; Teodosio, Maria; Leitão, FranciscoUnderstanding ecological, and socio-economical vulnerabilities is fundamental towards developing and implementing regional adaptation strategies to climate change. The Portuguese coast is situated in a transition zone between temperate ecosystems to the north, and subtropical with Mediterranean characteristics, to the south, with distinct oceanographic regions (north, centre, and south), fish assemblages and socioeconomic realities of fish communities across these regions. We develop a framework to assess fisheries climate vulnerability in each port. A total of 32 ecological and socio-economic indicators were used to measure exposure, sensitivity, and adaptive capacity of the fishing sector to climate change by combining i) environmental projections ii) information from fishing communities (surveys at ports) and iii) landings and socio-economic data from official statistics offices. The vulnerability to climate change across regions, and its expected impact on fishing fleets and local communities, was low-moderate. Such information will enable fishing communities and decision makers to respond to expected climate change effects and direct/indirect associated activities. This framework comprises background information for developing mandatory EU climate adaptation plans that aim to improve the resilience of fisheries socio-economic systems.
- Ecological sensitivity and vulnerability of fishing fleet landings to climate change across regionsPublication . Albo Puigserver, Marta; Bueno-Pardo, Juan; Pinto, Miguel; N. Monteiro, J.; Ovelheiro, Andreia; Teodosio, Maria; Leitão, FranciscoThe degree of exposure of fishing communities to environmental changes can be partially determined by the vulnerability of the target species and the landings composition. Hence, identifying the species that ecologically most contribute to the vulnerability of the landings are key steps to evaluate the risk posed by climate change. We analyse the temporal variability in intrinsic sensitivity and the ecological vulnerability of the Portuguese fisheries landings, considering the species proportions derived both from the weights and revenues. To account for the diversification of species of each fleet, we explored the species dependence of the fishery in combination with the vulnerability of them. The analyses were carried out separately for three fleet typologies and three regions. Opposite to what has been observed at a global scale, the ecological sensitivity of the fisheries landings between 1989 and 2015 did not display a decline across areas or fishing fleets. Considering each fleet independently, for trawling, where average vulnerability was lower than in the other fleets, the sensitivity of the landings increased since the 2000s. On the other hand, the high vulnerability found in multi-gear fleets was compensated by diversification of the species caught, while purse-seine fleets targeted low vulnerability species but presented a high fishery dependence on few species. The results highlight the importance of combining information on ecological vulnerability and diversification of fishing resources at a regional scale while providing a measure of the ecological exposure to climate change.
- Effect of bait type on the octopus fishery in Algarve, Southern PortugalPublication . Leitão, Francisco; Bueno-Pardo, Juan; Ovelheiro, Andreia; Monteiro, J. N.; Nobre, Daniela; Teodosio, MAIn Algarve, southern Portugal, a fishery regulation was established forbidding the use of live crab as bait for the octopus fishing. Such a regulation was not established under a scientific fundament. The objective of this work was to identify if using live crab as bait affects the octopus fishery. Time series (1989–2015) were analysed in order to calculate octopus catch rates (as Landing Per Unit Effort or LPUE) and revenues (as revenue per unit effort or RPUE) before and after the crab bait ban in 2009 and also by bait type (crab and fish) before ban. Overall, total annual fishing effort decreased as result of the decreasing number of boats and fishing days in the local and coastal fleets. After the ban both the LPUE and RPUE increased, with total landings showing no change through time but mean landings per boat increased. Between 1989 and 2009, the mean monthly fishing effort in the coastal fleet was higher when crab bait was used (3.88%) in comparison to using fish bait (0.3%). This result is superimposed by the large inter annual variability between the local and coastal fleets (39.11%). In consequence, no substantial evidence was found indicating that crab bait produced high octopus catch rates, while fishing effort indicated that such high octopus catch rate and revenue increase was due to the decline of number of boats and fishing effort, that was decreasing significantly regardless of the bait type and fleet before to crab ban, and not to the bait type used during this period.
- Environmental variability and fishing effects on artisanal flatfish fisheries along the Portuguese coastPublication . Baptista, Vânia; Blasco, Ignacio Pérez; Bueno-Pardo, Juan; Teodosio, Maria; Leitão, FranciscoAssessing the effects of fishing activity and environmental variability on fishing species might help to understand their fluctuations and to manage them accordingly. However, despite the increasing number of studies linking fisheries and environmental data, few had a multi-species approach considering flatfish species and different age groups. Therefore, this study aims to determine the effects of environmental and fishing related variables on commercial flatfish species across different regions of the Portuguese coast. For that, sea surface temperature, North Atlantic Oscillation, upwelling index, wind components, river discharges and fishing effort were related to landings per unit effort (LPUE) of five commercial flatfish species (Pleuronectes platessa, Dicologlossa cuneata, Microchirus spp., Solea lascaris, and Solea solea) fished by the artisanal fleet along different regions of Portuguese coast (Northwestern coast, Southwestern coast, and Southern coast), using a multi-model statistical approach from 1989 to 2009. The fishing effort had the same effect along the life cycle and was negatively related with LPUE trends for most of the species. Regarding to environmental variability, during early phases (larval to juvenile - age-group-0) the factors that affected the recruitment, in addition to being related to the physiological needs (e.g., sea surface temperature) of individuals that will trigger growth and survival, were related to larval transport and dispersion from offshore spawning areas to coastal nursery habitats beyond (e.g., wind components and upwelling). For juvenile and young-adult phases (age-groups I and II), the effects of environmental variability appeared to be linked to physiological needs important for growth and maturation (e.g., temperature). Concluding, different effects were observed depending on the region, species, and life-cycle phase. Therefore, these environmental-fishing relationships should be used when managing local fishing resources.
- Implications of warming on the morphometric and reproductive traits of the Green Crab, Carcinus maenasPublication . N. Monteiro, J.; Bueno-Pardo, Juan; Pinto, Miguel; Pardal, Miguel A.; Martinho, Filipe; Miguel de Sousa Leitão, FranciscoUnderstanding the relationship between environmental temperature and the biological traits of organisms is fundamental to inferring the potential impacts of climate change. In the case of marine poikilotherm species, seawater temperature is one of the main driving forces of biological processes, with consequences at higher levels of organization such as population and ecosystem. In this study, we analysed differences in maximum carapace width (CWmax), size at maturation, relative size at maturation, and duration of the reproductive season for the green crab (Carcinus maenas) along a temperature gradient. An extensive review of bibliographic data was performed on studies published between 1962 and 2020, gathering C. maenas data from 55 different populations, spread over 20 degrees of latitude and 14.2 °C of sea surface temperature (SST). In addition, green crab data were collected at five different lagoons and estuaries along the continental Portuguese coast. The relationship between average SST and CWmax, age of maturation, reduction of size at maturation, and duration of egg bearing was analysed to understand the role of SST in driving variation in these C. maenas characteristics across a latitudinal gradient. There was a significant relationship between SST and CWmax for males and SST and CW of females at maturation, respectively. The results extrapolate for each local projected temperature increase caused by climate change and suggest an effect on the morphometric and reproductive traits of C. maenas across regions. These changes comprise an overall reduction in C. maenas body size, an enlargement of the reproductive season, a shortening in the duration of larval developmental time, and a decrease in the relative size of crabs at maturation. Secondary consequences on the fecundity and connectivity of populations are discussed.
- Supply and larval traits at metamorphosis of a coastal marine invertebrate with a bi-phasic life cycle under contrasting oceanographic conditionsPublication . Rey, Felisa; Silva Neto, Gina M.; Bueno-Pardo, Juan; Bispo, Regina; Calado, RicardoPatterns of larval supply and larval condition at metamorphosis play key roles in the structure and dynamics of marine populations. Hence, biological and environmental conditions driving the dispersion of larval individuals, shape early life phenotypes, and influence their survival and post-settlement success. We performed a study over two consecutive years at Ria de Aveiro (Portugal), a coastal lagoon influenced by upwelling regimens in the North-eastern Atlantic. This study assessed the effect of contrasting oceanographic conditions on larval supply and larval traits at metamorphosis of the green crab Carcinus maenas. Crab megalopae were daily sampled and monitored in the laboratory until metamorphosis. Environmental conditions experienced by larvae in the field were estimated considering their expected planktonic larval duration, which was calculated for each individual using the size at metamorphosis and the average water temperature during larval development. Presence/absence, megalopa supply, and larval size were posteriorly modelled using generalized linear mixed models. The analysis of the two consecutive years showed haphazard patterns, revealing that both larval supply and phenotypic traits changed during and between supply seasons. The lunar cycle and environmental conditions were identified as drivers of the presence and supply of megalopae. Settlement events with weak upwelling index were influenced by sea temperature, while intense and constant upwelling events conditioned megalopa supply and performance at metamorphosis. In 2013, megalopae invaded the coastal lagoon in a more advanced physiological stage than in 2012 and/or under better nutritional conditions, probably due to stronger and more constant upwelling events during their pelagic larval life. Our results show that oceanographic processes stimulating upwelling and secondary production are sources of phenotypic variation at settlement, influencing both early benthic performance and adult population dynamics of marine organisms with bi-phasic life cycles.
- Trends and drivers of marine fish landings in Portugal since its entrance in the European UnionPublication . Bueno-Pardo, Juan; Pierce, Graham J.; Cabecinha, Edna; Grilo, Catarina; Assis, Jorge; Valavanis, Vasilis; Pita, Cristina; Dubert, Jesus; Leitão, Francisco; Queiroga, HenriqueMarine landings in Portugal have decreased at a higher rate than fishing effort in the last 20 years. Identifying the variables driving the quantity and composition of landings is pivotal to understand the dynamics of the fisheries sector, which entails complex social and environmental aspects. In this study, we investigate the main drivers of marine fish landings in continental Portugal between 1989 and 2014. To identify common trends in time series, and quantify the importance of environmental factors, we applied a dynamic factor analysis considering four regions and three types of gear (trawling, purse-seine, and a multi-gear fishery). Our results show the importance of fishing effort as the most relevant factor driving marine landings in Portugal, both at the long and short terms. In addition, the effect of environmental factors such as the winter river discharge and the spring East Atlantic Teleconnection index should not be neglected, probably through mechanisms affecting coastal productivity. We provide a comprehensive amount of information that permits to improve our understanding of the trends of the most important commercial species in Portugal during the period of study.