Climate influence on juvenile European sea bass (Dicentrarchus labrax, L.) populations in an estuarine nursery: A decadal overview.

Estuarine systems support the life cycle stages of commercially important marine fish and are influenced by large and local-scale climatic patterns. In this study, performed in the Mondego estuary, Portugal, we used an 11-year database (2003-2013) for analyzing the variability in the population of a marine juvenile migrant fish, the European sea bass Dicentrarchus labrax, regarding changes in abundance, population structure, growth rates, secondary production and annual day of peak abundance. Higher densities and production occurred in 2003, but no differences in 0-group growth could be observed.

Interannual abundance changes of gelatinous carnivore zooplankton unveil climate-driven hydrographic variations in the Iberian Peninsula, Portugal.

The persistent massive blooms of gelatinous zooplankton recorded during recent decades may be indicative of marine ecosystem changes. In this study, we investigated the potential influence of the North Atlantic climate (NAO) variability on decadal abundance changes of gelatinous carnivore zooplankton in the Mondego estuary, Portugal, over the period 2003-2013. During the 11-year study, the community of gelatinous carnivores encompassed a larger diversity of hydromedusae than siphonophores; the former dominated by Obelia spp.

Efficacy of single and multi-metric fish-based indices in tracking anthropogenic pressures in estuaries: An 8-year case study.

Facing a generalized increase in water degradation, several programmes have been implemented for protecting and enhancing the water quality and associated wildlife, which rely on ecological indicators to assess the degree of deviation from a pristine state. Here, single (species number, Shannon-Wiener H', Pielou J') and multi-metric (Estuarine Fish Assessment Index, EFAI) community-based ecological quality measures were evaluated in a temperate estuary over an 8-year period (2005-2012), and established their relationships with an anthropogenic pressure index (API). Single metric indices were highly variable and neither concordant amongst themselves nor with the EFAI.

Long-term functional changes in an estuarine fish assemblage.

The functional diversity of the fish assemblages of the Mondego estuary was studied for a discontinuous 30-year period (1988-2012). During this time, hydrological changes occurred due to man-induced alterations and weather extremes. These changes led to alterations in the structure and function of the fish community.