Browsing by Author "Picado, Ana"
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- Assessment of habitat suitability for common cockles in the Ria the Aveiro Lagoon under average and projected environmental conditionsPublication . Matos, Fábio L.; Vaz, Nuno; Picado, Ana; Dias, João M.; Maia, Francisco; Gaspar, Miguel; Magalhães, LuísaThe common cockle Cerastoderma edule is a widespread bivalve species inhabiting estuarine systems across the North East Atlantic, where it provides several ecosystem services, and represents a valuable fishery resource for local economies. However, anthropogenic pressure and more frequent extreme weather events threaten the resilience of the species. Spatially explicit information on species distribution is critical for the implementation of management and conservation practices. This study assessed the potential distribution of C. edule in the Ria de Aveiro by estimating the habitat suitability using an ensemble approach based on ecological niche modeling and recently developed hydrodynamic and water quality models to forecast both average and projected estuarine conditions. The models were developed for the summer of 2013 and spring of 2019 and potential range shifts in the species distribution were forecasted under projected environmental conditions: high and low estimates of freshwater discharge, a 2 degrees C increase in water temperature, and the combined effect of low freshwater discharge and increased water temperature. The results suggest that salinity, time of submersion, and current velocity play an important role in the distribution of cockles, and large areas were consistently classified with high habitat suitability. Increased freshwater discharge (both seasons) and low discharge coupled to increased temperature (spring) resulted in large decreases in suitable habitat. Conversely, low freshwater discharges and average (unchanged) temperatures increased the suitable habitat in the outermost regions of the Ria. The spatially explicit information provided contributes to a better understanding of the vulnerability of C. edule in the Ria de Aveiro to extreme weather events (e.g., droughts, river floods) and may support adaptive management strategies of the cockle fishery during these conditions. Moreover, this approach can be transferred to other estuarine ecosystems for which data describing the environmental conditions (e.g., derived from numerical models), and information about species presence are available (including data-poor species).
- Biomarkers: a strategic tool in the assessment of environmental quality of coastal watersPublication . Picado, Ana; Bebianno, Maria João; Costa, M. H.; Ferreira, A.; Vale, C.Ecosystems are under the pressure of complex mixtures of contaminants whose effects are not always simple to assess. Biomarkers, acting as early warning signals of the presence of potentially toxic xenobiotics, are useful tools for assessing either exposure to, or the effects of these compounds providing information about the toxicant bioavailability. In fact, it has been argued that a full understanding of ecotoxicological processes must consider an integrated multi-level approach, in which molecular impact is related with higher-order biological consequences at the individual, population and community levels. Monitoring programs should make use of this tool to link contaminants and ecological responses fulfilling strategies like those launched by OSPAR (Commissions of Oslo and Paris) Convention on the protection of the marine environment of the North-East Atlantic and the International Council for the Exploration of the Sea (ICES). An overview of the work done in the past few years using biomarkers as in situ tools for pollution assessment in Portuguese coastal waters is presented as a contribution to the set up of a biomonitoring program for the Portuguese coastal zone. Considering the data set available the biomonitoring proposal should include the analysis of biomarkers and effects at individual levels. The aim of the program will include a spatial and temporal characterization of the biomarkers acetyl-cholinesterase, metallothioneins, DNA damage, adenylate energy charge and scope-for-growth levels. The investigation of the spatial variation of biomarkers is crucial to define sites for long term monitoring, which will be integrated with a chemical monitoring program. This framework will be a major contribution to the implementation of a national database for the use of biomarkers along the Portuguese coast.