Browsing by Author "Martinho, Filipe"
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- Colonization and nursery habitat use patterns of larval and juvenile flatfish species in a small temperate estuaryPublication . Primo, Ana Ligia; Azeiteiro, Ulisses; Marques, Sónia; Martinho, Filipe; Baptista, Joana; Pardal, MiguelMigrations between coastal and estuarine nursery areas are essential for successful completion of the life cycle of several marine fish. The present study evaluates the use of a small temperate estuary, the Mondego, Portugal, as a nursery habitat for several flatfishes during their early life stages. Data from seasonal and diel larval sampling at the mouth of the estuary and both larvae and juvenile monthly spatial distribution in the estuary (2005–2009) were gathered in order to investigate the life cycle of Platichthys flesus, Solea solea and Solea senegalensis. Larvae entrance in the estuary occurred mainly during summer and autumn with no evidence for diel or tidal vertical stratification. S. senegalensis larvae were present in all seasons at downstream areas presenting low successful settlement and juveniles' densities inside the estuary. Conversely, P. flesus and S. solea were mainly present as juveniles with upstream areas being preferred by flounder. Both species larvae seemed to settle in nearby coastal areas. The importance of theMondego estuary for flatfishes differed according to the species, playing an important rolemainly during the first year for all species. The present study highlights the importance of integrating larval and juvenile stages of fish to assess the very important role of estuaries as nursery areas.
- Shifts in estuarine zooplankton variability following extreme climate events: a comparison between drought and regular yearsPublication . Marques, Sónia Coutrim; Primo, Ana Lígia; Martinho, Filipe; Azeiteiro, Ulisses; Pardal, MiguelClimate change will likely lead to an increase in temperature and an occurrence of extreme droughts and floods in the 21st century. In particular, coastal and estuarine systems are highly sensitive to climate extremes and changing precipitation patterns, and thus offer invaluable scenarios for the evaluation of climate variability. Zooplankton assemblages and hydroclimate variables were monitored for 8 yr. The main objective was to assess the impact of climate variability, particularly of the 2 most recent drought events in the Mondego estuary (Portugal, southern Europe), which occurred in 2004−2005 and 2007−2008, on the zooplankton population dynamics, with emphasis on how stochastic extrinsic perturbation might influence these populations. Principal component analysis revealed dramatic environmental changes during drought periods, which were reflected in the seasonal and inter-annual patterns in the zooplankton, indicating that hydroclimate forcing is critical in defining zooplankton dynamics. Lower precipitation and higher salinities were the main drivers for the observed patterns, i.e. a major penetration of seawater led to a higher prevalence of marine species. Results also revealed a conspicuous increase in warm water taxa since 2006, which was significantly related to pronounced changes in water temperature. This synchronous variability between water temperature and zooplankton abundance, which had not been evaluated and discriminated in previous studies, suggests the potential impact of warming on zooplankton assemblages. Hence, this study demonstrates the crucial role of zooplankton as valuable indicators of hydrological changes associated with climate factors in estuarine ecosystems.