Browsing by Author "Pereira, Eduarda"
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- Changes in zooplankton communities along a mercury contamination gradient in a coastal lagoon (Ria de Aveiro, Portugal)Publication . Cardoso, Patricia; Marques, Sónia; D’Ambrosio, Maria; Pereira, Eduarda; Duarte, Armando; Azeiteiro, Ulisses; Pardal, MiguelThe main objective of this paper was to evaluate the impact of mercury on the zooplankton communities’structure and functioning and their bioaccumulation patterns along a contamination gradient in a temperate coastal lagoon. Our results demonstrated that total abundance was not negatively affected by Hg contamination, since the most contaminated areas presented the highest values, being the copepod Acartia tonsa the dominant species, which means that it is a very well adapted and tolerant species to mercury. Nevertheless, negative effects were observed in terms of species diversity, since the most contaminated areas presented the lowest values of species richness, evenness and heterogeneity. Moreover,the spatial mercury gradient was reflected on the bioaccumulation patterns of the zooplankton communities. This reinforces the idea that zooplankton can be considered as an important vehicle of mercury transfer through the food pelagic web since it constitutes a primordial food resource for several commercial fish species.
- Mercury bioaccumulation and the population dynamics of Mesopodopsis slabberi (Crustacea: Mysidacea) along a mercury contamination gradientPublication . D’Ambrosio, Maria; Marques, Sónia; Azeiteiro, Ulisses; Pardal, Miguel; Pereira, Eduarda; Duarte, Armando; Cardoso, PatriciaThe mercury bioaccumulation and population dynamics of the mysid Mesopodopsis slabberi was assessed along a mercury gradient in Ria de Aveiro (Portugal). M. slabberi is one of the most important mysid species in European temperate coastal shallow waters playing a key ecological role. Nevertheless, no references were found concerning the possible consequences of the Hg on the trophodynamics of these coastal ecosystems. M. slabberi showed a clear bioaccumulation along the Hg gradient and through life, with mature females reaching the highest concentrations. In terms of population structure, higher densities and biomasses of M. slabberi were assessed in the most contaminated areas contrarily to the least polluted areas. Despite the mercury accumulation in its tissues no strong negative effects on the structure and population dynamics of the species were observed. However, mysids might be important in the transfer of metals from the sediments and zooplankton to higher trophic levels such as fishes, most of them with commercial interest.
- Temporal characterization of mercury accumulation at different trophic levels and implications for metal biomagnification along a coastal food webPublication . Cardoso, Patricia; Pereira, Eduarda; Duarte, Armando; Azeiteiro, UlissesThe main goal of this study was to assess temporal mercury variations along an estuarine food web to evaluate the mercury contamination level of the system and the risks that humans are exposed to, due to mercury biomagnification. The highest mercury concentrations in the sediments and primary producers (macrophytes) were observed during winter sampling. Instead, the highest mercury concentrations in the water, suspended particulate matter as well as in the zooplanktonic and suprabenthic communities were observed during summer sampling. Evidences of mercury biomagnification along the food web were corroborated by the positive biomagnification factors, particularly for omnivorous macrobenthic species. Comparing the mercury levels at distinct components with several environmental quality criteria it suggests that sediments, water and edible species (e.g., bivalve Scrobicularia plana and the crustacean Carcinus maenas) presented higher mercury levels than the values accepted by legislation which represent a matter of concern for the environment and human health.
- The effects of mercury on the dynamics of the peracarida community in a temperate coastal lagoon (Ria de Aveiro, Portugal)Publication . Cardoso, Patricia; D’Ambrosio, Maria; Marques, Sónia; Azeiteiro, Ulisses; Coelho, João; Pereira, EduardaThis study focuses on the impact of mercury on the dynamics and bioaccumulation patterns of suprabenthic peracarida community along a mercury gradient. Suprabenthic peracarida was negatively affected in terms of biomass, diversity and productivity. Mysids including Mesopodopsis slabberi dominated the community,presenting a regular distribution along the Hg gradient, so are considered tolerant species to mercury. Then, isopods, the second most abundant group, dominated in the most contaminated areas being considered also a tolerant group. Contrarily, amphipods were negatively correlated with higher Hg concentrations, dominating in the intermediate areas, thus are considered more sensitive species. In addition, isopods and amphipods were the taxa with higher mercury body burden, followed by mysids. This paper highlights the importance of suprabenthic peracarida as a vehicle of mercury transference through the estuarine trophic web since it is a main link between benthic and pelagic levels and an essential food resource for numerous fish species.