Browsing by Author "Martinho, Filipe"
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- Contrasting links between growth and survival in the early life stages of two flatfish speciesPublication . Primo, Ana Ligia; Vaz, Ana Catarina; Crespo, Daniel; Costa, Filipe; Pardal, Miguel; Martinho, FilipeUnderstanding the causes of variation in recruitment of marine fishes has been a central goal over the last century. However, the relationship between year class strength and larval growth and survival is poorly known for most species. The main goal of this study was to investigate the relationships between larval traits and year class strength of two flatfish species in an nursery estuary. We examined the effects of the variation in the early life characteristics (pelagic larval growth, pelagic larval duration, size-at-hatching and size-at-settlement) on post-settlement survival of flounder Platichthys flesus and common sole Solea solea in the Mondego estuary (Portugal) over a 5-year period (2011–2015). The two flatfish species showed distinct larval traits variation during the study period, mainly related with location of the spawning ground and intrinsic biologic patterns. Flounder was able to delay metamorphosis while gathering energy and/or waiting for suitable environmental cues from estuarine origins while sole take advantage of better environmental conditions due to a later hatching. Early fast growth were strongly related with subsequent growth, affecting larval survival. Both growth and larval traits variation during the studied period were strongly related with temperature. This study highlights the importance of early growth for fish survival and contributes with key information on fish early life stages that will support a better management of fish stocks.
- Does an invasive bivalve outperform its native congener in a heat wave scenario? A laboratory study case with Ruditapes decussatus and R. philippinarumPublication . Crespo, Daniel; Leston, Sara; Rato, Lénia D.; Martinho, Filipe; Novais, Sara C.; Pardal, Miguel A.; Lemos, Marco F. L.Global warming and the subsequent increase in the frequency of temperature anomalies are expected to affect marine and estuarine species’ population dynamics, latitudinal distribution, and fitness, allowing non-native opportunistic species to invade and thrive in new geographical areas. Bivalves represent a significant percentage of the benthic biomass in marine ecosystems worldwide, often with commercial interest, while mediating fundamental ecological processes. To understand how these temperature anomalies contribute to the success (or not) of biological invasions, two closely related species, the native Ruditapes decussatus and the introduced R. philippinarum, were exposed to a simulated heat wave. Organisms of both species were exposed to mean summer temperature (~18 C) for 6 days, followed by 6 days of simulated heat wave conditions (~22 C). Both species were analysed for key ecological processes such as bioturbation and nutrient generation—which are significant proxies for benthic function and habitat quality—and subcellular biomarkers—oxidative stress and damage, and energetic metabolism. Results showed subcellular responses to heat waves. However, such responses were not expressed at the addressed ecological levels. The subcellular responses to the heat wave in the invasive R. philippinarum pinpoint less damage and higher cellular energy allocation to cope with thermal stress, which may further improve its fitness and thus invasiveness behaviour.
- Evidence for changes in estuarine zooplankton fostered by increased climate variancePublication . Marques, Sónia Cotrim; Pardal, Miguel Ângelo; Primo, Ana Lígia; Martinho, Filipe; Falcão, Joana; Azeiteiro, Ulisses; Molinero, Juan CarlosEstuaries are among the most valuable aquatic systems in terms of their services to human welfare. They offer an ideal framework to assess multiscale processes linking climate and food web dynamics through the hydrological cycle. Resolving food web responses to climate change is fundamental to resilience management of these threatened ecosystems under global change scenarios. Here, we examined the temporal variability of the plankton food web in the Mondego Estuary, central Iberian Peninsula, over the period 2003 to 2012. The results pointed out a cascading effect from climate to plankton communities that follow a non-stationary behavior shaped by the climate variance envelope. Concurrent changes in hydrographic processes at the regional, that is, upwelling intensity, and local, that is, estuarine hydrology, scales were driven by climatic forcing promoted by the North Atlantic Oscillation; the influence of which permeated the physical environment in the estuary affecting both autotrophic and heterotrophic communities. The most conspicuous change arose around 2008 and consisted of an obvious decrease in freshwater taxa along with a noticeable increase in marine organisms, mainly driven by gelatinous zooplankton. The observed increase in small-sized cosmopolitan copepods, that is, Clausocalanus arcuicornis, Oithona plumifera, thermophilic species, that is, Penilia avirostris, and gelatinous zooplankton suggests a structural change in the Mondego plankton community. These results provide empirical support to the expectation that expanding climate variance changes plankton structure and functioning, likely fostering trophic interactions in pelagic food webs.
- Predicting zooplankton response to environmental changes in a temperate estuarine ecosystemPublication . Marques, Sónia Cotrim; Azeiteiro, Ulisses Miranda; Leandro, Sérgio Miguel; Queiroga, Henrique; Primo, Ana Ligia; Martinho, Filipe; Viegas, Ivan; Pardal, Miguel ÂngeloA novel strategy that allows to predict the responses of zooplanktonic species to environmental conditions in an estuarine temperate ecosystem (Mondego estuary) is presented. It uses 12 indicator species from the zooplanktonic Mondego database (102 species) that are common members of the different habitats, characterized by their specific hydrological conditions. Indicator-species analysis (ISA) was used to define and describe which species were typical of each of the five sampling stations in a 4-year study (2003–2006). First, a canonical correspondence analysis (CCA) was carried out to objectively identify the species-habitat affinity based on the relationship between species, stations and environmental data. Response curves for each of the zooplanktonic species, generated by univariate logistic regression on each of the independent variables temperature and salinity, were generally in agreement with the descriptive statistics concerning the occurrence of those species in this particular estuarine ecosystem. Species-specific models that predict probability of occurrence relative to environmental parameters like salinity, water temperature, turbidity, chlorophyll a, total suspended solids and dissolved oxygen were then developed for the zooplanktonic species. The multiple logistic models used contained between 1 and 3 significant parameters and the percentage correctly predicted was moderate to high, ranging from 62 to 95%. The predictive accuracy of the model was assured by direct comparison of model predictions with the observed occurrence of species obtained in 2006 (validation) and from data collected in the early 2000s in another Portuguese estuary - Ria de Aveiro (Canal de Mira), a complex mesotidal shallow coastal lagoon. The regression logistic model here defined, correctly suggested that the distribution of zooplankton species was mainly dependent on salinity and water temperature. The logistic regression proved to be a useful approach for predicting the occurrence of species under varying environmental conditions at a local scale. Therefore, this model can be considered of reasonable application (and should be tested in other estuarine systems) due to its ability to predict the occurrence of individual zooplanktonic species associated with habitat changes.
- Spatial distribution and seasonal patterns of the siphonophores Muggiaea atlantica and Muggiaea kochii in a temperate estuarine ecosystemPublication . D'Ambrosio, Mariaelena; Primo, Ana L.; Pardal, Miguel A.; Martinho, Filipe; Guerrero, Elena; Marques, Sónia C.This study analysed the distribution and abundance of both polygastric (asexual) and gonophores of the calycophoran siphonophores Muggiaea atlantica and Muggiaea kochii in the Mondego estuary (Portugal), as well as the influence of local environment and prey availability on the observed patterns. Samples were collected in three different zones of the estuary, from December 2013 to November 2015. In general, both species nectophores and total gonophores followed a similar trend, with higher abundances during spring-summer periods and increased densities in the downstream areas of the estuary, where the marine influence is stronger. Inter-annual differences occurred mainly for M. atlantica nectophores, which showed higher abundances in 2015, particularly in the upstream areas. Both species displayed a shift in the annual peak abundance, from bimodal in 2014 to unimodal in 2015. Patterns observed were not only strongly related with an increase of the marine influence in the estuary, but also with the presence of zooplanktonic prey, such as cirripede cypris, calanoid nauplius, Poecilostomatoida, and copepodites of Cyclopoida. This study represents a step towards a better knowledge of the biology and ecology of siphonophores.
- Surf zone zooplankton communities from the west coast of the Iberian Peninsula: influence of season, substrate type and environmental factorsPublication . Guerreiro, Milene Alexandra; Marques, Sónia Cotrim; Martinho, Filipe; Azeiteiro, Ulisses Miranda; Pardal, Miguel Ângelo; Primo, Ana LígiaStudies on surf zone zooplankton biodiversity and population dynamics processes remain scarce in comparison to other coastal areas. In this work, we analysed the seasonal (winter/summer) variability of the surf zone zooplankton assemblage structure and copepod biomass of distinct areas with different substrate types (sandy beaches/rocky shores) at the west coast of the Iberian Peninsula (Portugal). Cypris of Cirripedia and Acartia clausi prevailed during summer at both areas. In the winter, Paracalanus parvus and Temora longicornis were the most abundant species at sandy beaches, while Harpacticoida n.id.1 and Euterpina acutifrons dominated at rocky shores. Copepod biomass was higher during the winter and in sandy beaches. Zooplankton showed distinct community structure according to season and substrate type, with Harpacticoids and cirripeds being the main responsible for seasonal differences, while fish eggs and harpacticoids were mainly responsible for differences among substrates. Surf zone assemblages were influenced by temperature, chlorophyll a and local hydrodynamics, which reflects species seasonal reproduction and drift in the water column.
- Trophic links and nutritional condition of fish early life stages in a temperate estuaryPublication . Primo, Ana Lígia; Correia, Catarina; Marques, Sónia Cotrim; Martinho, Filipe; Leandro, Sérgio; Pardal, MiguelThe physiological and nutritional condition of fish larvae affect their survival and thus, the success of estuaries as nursery areas. Fatty acid composition has been useful to determine fish nutritional condition, as well as trophic relationships in marine organisms. The present study analyses the fatty acid (FA) composition of fish larvae during spring and summer in the Mondego estuary, Portugal. FA composition, trophic markers (FATM) and fish nutritional condition was analysed for Gobiidae and Sardina pilchardus larvae and the relationships with the local environment evaluated. Results showed that both taxa differed mainly in the stearic acid (C18:0) and eicosapentaenoic acid (EPA) content, with important amounts in Gobiidae and S. pilchardus, respectively. Gobiidae larvae presenting high nutritional condition and omnivore FATM. Fatty acid composition seems to be related with their natural habitat selection and food availability, while fish larvae nutritional condition also showed a strong link with the water temperature and presence of potential predators. This study suggests that FA composition can be a useful tool in assessing planktonic trophic relationships and in identifying species natural habitat.
- Water and otolith chemistry: implications for discerning estuarine nursery habitat use of a juvenile flatfishPublication . Martinho, Filipe; Pina, Beatriz; Nunes, Margarida; Vasconcelos, Rita P.; Fonseca, Vanessa F.; Crespo, Daniel; Primo, Ana Lígia; Vaz, Ana; Pardal, Miguel A.; Gillanders, Bronwyn M.; Tanner, Susanne E.; Reis-Santos, PatrickVariations in otolith elemental composition are widely used to reconstruct fish movements. However, reconstructing habitat use and environmental histories of fishes within estuaries is still a major challenge due to the dynamic nature of these coastal environments. In this study, we performed a laboratory experiment to investigate the effects of variations in salinity (three levels; 5, 18, 30) and temperature (two levels; 16, 21 C) on the otolith elemental composition (Mg:Ca, Mn:Ca, Sr:Ca, Ba:Ca) of juvenile Senegalese sole Solea senegalensis. Temperature and salinity treatments mirrored the natural conditions of the estuarine habitats occupied by juvenile Senegalese sole, thereby providing information on the applicability of otolith microchemistry to reconstruct habitat use patterns within estuarine nurseries, where individual fish move across complex salinity and temperature gradients. While Sr:Ca and Ba:Ca in otoliths were both positively related to salinity, no temperature effect was observed. Partition coefficients, proxies for element incorporation rates increased with increasing salinity for Sr (DSr) and Ba (DBa). In contrast, salinity and temperature had little influence on otolith Mn:Ca and Mg:Ca, supporting physiological control on the incorporation of these elements. Our results are a stepping stone for the interpretation of otolith chemical profiles for fish collected in their natural habitats and contribute to better understanding the processes involved in otolith element incorporation.