Browsing by Author "Martinho, Filipe"
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- Effects of climate variability on an estuarine green crab Carcinus maenas populationPublication . Monteiro, J. N.; Pinto, Miguel; Crespo, Daniel; Pardal, Miguel A.; Martinho, FilipeThe increase in frequency and intensity of extreme climate events over the last few decades has been leading to profound changes in estuarine and marine ecosystems worldwide, with strong implications for the species inhabiting these ecosystems as well as for the services provided by them. In this study, we analysed the effects of climate variability on the temporal and spatial variations in population dynamics of the green crab Carcinus maenas in the Mondego estuary (Portugal), between 2003 and 2018. In this 15-year period, a greater recruitment of C. maenas was observed during drought periods, periods which was matched by an increase in secondary production. Ontogenic stage segregation was also observed, with juveniles being found mainly in the further upriver areas of the estuary. The estuarine population was mainly composed of the green morphotype, with the orange and red morphotypes present in more downstream areas of the estuary. Redundancy analysis (RDA) showed high spatial and temporal variability of C. maenas in the estuary which was related with environmental changes over the 15-year period. A correlation between C. maenas biological features and several local-scale (salinity and river runoff) and large-scale (North Atlantic Oscillation index and Eastern Atlantic pattern) environmental variables was identified through cumulative sums analysis (CUSUM), indicating a strong environmental control on C. maenas population dynamics. This paper shows the importance of relatively long-term datasets to unravel the effects of extreme weather events due to climate change on key epibenthic estuarine species, and also how they might cope with a changing marine environment.
- Habitat suitability of two flagship species, hippocampus hippocampus and Hippocampus guttulatus, in the Atlantic coast of the Iberian Peninsula - implications for conservationPublication . Peiffer, Friederike; Lima, André Ricardo Araujo; Henriques, Sofia; Pardal, Miguel A.; Martinho, Filipe; Gonçalves, Jorge Manuel Santos; Gonçalves, Emanuel J.; Correia, Miguel; Silva, Gonçalo Jorge FrancoAnthropogenic pressures on marine ecosystems are increasing worldwide, causing loss of biodiversity and ecosystem functioning, and driving species towards risk of extinction. To protect vulnerable species and habitats, Marine Protected Areas (MPAs) are increasingly established worldwide as conservation measures. Seahorses act as flagship species for coastal ecosystem conservation due to their charismatic appearance and high vulnerability to habitat degradation. Here, the habitat suitability of the two European seahorse species, Hippocampus hippocampus and Hippocampus guttulatus, was assessed along the western Iberian Peninsula, using an ensemble species distribution modelling approach. Furthermore, the coverage of their core habitat (relative habitat suitability (HS) ≥ 0.5) with MPAs was estimated. The results show that the main drivers for habitat suitability were distance to the coast, aspect of the seafloor, tidal amplitude, and temperature. However, the importance differed between the two species. The suitable habitat of H. hippocampus extended to higher distances to the coast, while H. guttulatus were mostly restricted to areas in the vicinity of the coast and facing away from the open sea (i.e., the westerly aspect of the seafloor). Furthermore, temperature contributes more to the variation in habitat suitability in H. hippocampus than in H. guttulatus. The areas with the highest habitat suitability are estuarine or inlet waters and sheltered coasts in northwestern Spain, central and south of Portugal. Both species’ core habitats are covered by about 19–20 % with implemented protected areas in Portugal. In comparison, there is less coverage for both species in Spain, with 12 % for H. guttulatus and 6 % for H. hippocampus. Besides, zones of full protection cover less than 0.5 % of the core habitat while the rest of the protected areas provide only moderate to low restrictions and do not specifically address the protection of seahorses in their management plans. The results provide useful information on the distribution and the different habitat preferences of the two species, indications for further monitoring of populations, and recommendations for efficient spatial conservation areas that can protect the species and other associated vulnerable species and habitats.
- High-density SNP panel provides little evidence for population structure in European sea bass (Dicentrarchus labrax) in waters surrounding the UKPublication . Taylor, Martin I.; Lamb, Philip D.; Coscia, Ilaria; Murray, David S.; Brown, Mary; Cameron, Tom C.; Davison, Phil I.; Freeman, Howard A.; Georgiou, Katerina; Grati, Fabio; Haugen, Thrond; Karachle, Paraskevi K.; Kennedy, Richard; Lanssens, Thomas; Lincoln, Harriet; Martinho, Filipe; McCarthy, Ian; Petroutsos, Spyros-Iasonas; Pita, Pablo; Pontes, João; Baucells, Marta P.; Rangel, Mafalda; Roche, William; Sbragaglia, Valerio; Sturrock, Anna M; Taylor, Michelle L; Wogerbauer, Ciara; Veiga, Pedro; Verver, Sieto; Weltersbach, Marc Simon; Hyder, Kieran; Stewart W GrantThe European sea bass (Dicentrarchus labrax) is a commercially and recreationally important fish widely, distributed across the Northeast Atlantic Ocean and Mediterranean Sea. Two distinct lineages that represent the Atlantic and Mediterranean regions have been previously identified, with a hybrid zone close to the Almeria-Oran front. The presence of fine-scale population structure within the Northeast Atlantic region is less clear. Here, we investigated population structure in adult samples obtained from the northern part of the Atlantic range surrounding the UK, Ireland, Belgium, Germany, France, the Netherlands, and Norway, along with outgroups from Portugal and the Mediterranean, using a panel of 41 K single nucleotide polymorphism markers. Population structure among Northeast Atlantic Ocean samples was weak in both spawning-(FST = 0.00022) and feeding-(FST = 0.00032) season data sets, with small pairwise FST values between sample pairs. However, average FST was larger between spawning samples than between feeding samples, with a pattern of isolation-by-distance among the spawning samples, but not the feeding samples, suggesting some biologically meaningful population structure. The largest pairwise FST values at both International Council for the Exploration of the Sea (ICES) rectangle and division scales involved a sample from the west of Ireland. We found no evidence of a gradient in "Mediterranean" ancestry among samples collected around the UK in our data set or in a reanalysis of a published data set where such a pattern had been previously identified. In summary, there was no evidence that sea bass in different ICES divisions within the Northeast Atlantic Ocean represents genetically separate populations. Further work is required to reconcile evidence from tagging and modelling studies that suggest the potential for demographic independence with the genetic data.
- 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.
- Projected climate change and limited dispersal potential threaten the seahorse species Hippocampus hippocampus and Hippocampus guttulatusPublication . Peiffer, Friederike; Assis, Jorge; Lima, André R. A.; Henriques, Sofia; Pardal, Miguel A.; Martinho, Filipe; Gonçalves, Jorge Manuel Santos; Gonçalves, Emanuel J.; Correia, Miguel; Silva, Gonçalo J. F.Climate change is predicted to drive species redistribution, altering the composition of marine communities and affecting ecosystem functioning. There is increasing evidence that fish distributions follow a trend of poleward expansion, while realised niches often decrease in range size. This study aimed to assess the influence of oceanographic connectivity and intrinsic dispersal mechanisms on changes in suitable habitats of the European seahorses (Hippocampus hippocampus and Hippocampus guttulatus) from the present (2010–2020) until the end of the century (2090–2100). Habitat suitability was assessed using Ensemble Species Distribution Modelling under two Shared Socio-Economic Pathways (SSP2 and SSP5) coupled with biophysical modelling to estimate oceanographic connectivity. The results show that intrinsic dispersal mechanisms and oceanographic connectivity limit the northward range expansion, while predicted habitat loss remained constant in all dispersal scenarios, with the highest habitat loss forecasted in the Mediterranean and northern Africa. Consequently, considering restricted dispersal, H. guttulatus was projected to experience a negative range change (or habitat contraction [-45% (SSP5)] as opposed to an expansion with unlimited dispersal (standard model) [+ 6% (SSP5)]. On the other hand, for H. hippocampus, a more limited range expansion [+ 8% (SSP5)] was forecasted compared to the standard model [+ 17% (SSP5)]. In addition, the lower emission scenario (SSP2) resulted in half of the habitat losses, while maintaining climate refugia for H. guttulatus populations in the north Mediterranean, Iberian Atlantic Coast, and Black Sea. This study highlights the importance of considering dispersal abilities when assessing climate change impacts on marine species distribution.
- Resultados preliminares de um estudo sobre os efeitos da aplicação foliar de 2,4-D e potássio sobre o calibre do fruto da clementina ‘Mioro’Publication . Faustino, Filipe; Faustino, Miguel; Martinho, Filipe; Oliveira, Cristina; Duarte, AmilcarAs clementinas apresentam boas características organoléticas e ausência de sementes, o que é apreciado pelos consumidores e faz com que estejam entre os grupos de citrinos mais cultivados na Península Ibérica. Entre as clementinas, a cultivar ‘Mioro’ tem suscitado interesse pela sua precocidade, mas o vingamento é em alguns casos excessivo e os frutos apresentam um baixo calibre. A monda de frutos é usada para diminuir a competição e aumentar o calibre do fruto, mas é bastante dispendiosa e o seu efeito sobre o calibre das clementinas que ficam na árvore é pouco significativo, sobretudo quando é executado demasiado tarde. Em diversos países, incluindo Espanha, as auxinas são usadas vulgarmente para aumentar o calibre de clementinas e outras tangerinas. Porém, a sua aplicação não é eficaz em todas as cultivares de tangerineira. Mesmo nas cultivares em que as auxinas aumentam o calibre do fruto, a sua eficácia depende da auxina aplicada e para cada cultivar é necessário determinar o momento ótimo de aplicação e a concentração a usar. A aplicação de potássio por via foliar também tem um efeito positivo sobre o calibre do fruto, mas a sua eficácia depende do número de aplicações, do(s) momento(s) de aplicação e da concentração usada. Neste estudo foi testada a aplicação de 2,4-D a duas concentrações (10 e 30 mg L-1) e a aplicação foliar de óxido de potássio (uma e três aplicações), num desenho experimental em parcelas divididas (split-plot), com subparcelas de pelo menos 10 árvores. Os resultados obtidos até agora permitem concluir que a aplicação de 2,4-D provocou um aumento significativo do calibre do fruto, sobretudo quando aplicado a uma concentração de 30 mg L-1. A aplicação de potássio não provocou um aumento significativo do calibre do fruto, relativamente à testemunha.