Suchergebnisse

Government of Andalusia, Spain ; European Regional Development Fund (FEDER) ; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) ; University of Cadiz ; Government of Andalusia, Spain: P09-RNM-5136 ; CAPES: 0362-10/7 ; The present study investigated possible adverse outcomes in the marine clams Ruditapes philippinarum exposed to sediment affected by wastewater discharges at the Bay of Cadiz (SW, Spain). Six locations representing five cities were chosen for the sediment sampling during winter and summer seasons: P1 - Chiclana de la Frontera, P2 - Puerto Real, P3 - Cadiz, P4 and P5 - El Puerto de Santa Maria, P6 - Rota (reference site). Biochemical biomarkers were explored in clams after 14-days of exposure under controlled conditions, that included changes in cellular energy status (total lipids content TLP and mitochondrial electron transport activity MET), gametogenic activity (dopamine and ALP levels), metabolism of monoamines (monoamine oxidase activity - MAO), inflammation and spawning properties (cyclooxygenase activity - COX). Wastewater discharges induced energy budget alterations, as suggested by MET decrease (P4 and P5) and accumulation of To (P1, P2 and P3) in gonads. ALP levels (P1, P2 and P3), dopamine (P2) and COX activity (P1, P2, P3, P4 and P5) decreased in clams after the exposure to summer sediments. MAO increased in clams exposed to winter (P1 and P2) and summer (P3 and P4) sediments. Wastewater discharges composition changed between different seasons, mainly leading to oxidative stress, inflammation (COX activity and ALP levels) and spawning delay in summer. This study highlights the importance of considering reproduction of marine biota when assessing adverse effects of wastewater discharges. Continuous release of wastewater adequately threated or not, in aquatic ecosystems may culminate in adverse effects to the local benthic biota. (C) 2015 Elsevier Ltd. All rights reserved.

Abstract Upwelling events off the Southwest coast of Portugal can trigger phytoplankton blooms that are important for the fisheries and aquaculture sectors in this region. However, climate change scenarios forecast fluctuations in the intensity and frequency of upwelling events, thereby potentially impacting these sectors. Shifts in the phytoplankton community were analysed from the end of 2008 until the beginning of 2012 by examining the bio-optical properties of the water column, namely the absorption coefficients for phytoplankton, non-algal particles and coloured dissolved organic matter (CDOM). The phytoplankton community was assessed by microscopy, with counts from an inverted microscope, and by chemotaxonomic methodologies, using pigment concentrations determined by High-Performance Liquid Chromatography (HPLC). Results both from microscopy and from chemotaxonomic methods showed a shift from diatom dominance related to bloom conditions matching upwelling events, to small flagellate dominance related to no-bloom conditions matching relaxation of upwelling. During bloom conditions, light absorption from phytoplankton increased markedly, while non-algal particles and CDOM absorption remained relatively constant. The dynamics of CDOM in the study area was attributed to coastal influences rather than from phytoplankton origin. Changes in phytoplankton biomass and consequent alterations in phytoplankton absorption coefficients were attributed to upwelling regimes in the area. Bio-optical parameters can contribute to environmental monitoring of coastal and oceanic waters, which in the case of the European Union, involves the implementation of the Water Framework, Marine Strategy Framework and Marine Spatial Planning Directives.