Assessing long-term changes in potential ecosystem services of a peri-urbanizing Mediterranean catchment.

Society depends on goods and services provided by ecosystems, not only for survival but also for general wellbeing. Over the last decades, peri-urban areas have been subject to the pressure of urbanization and, thus, land-use changes. These changes modify the natural ecosystems and their ability to support human security and safety, but the extent of these impacts is not well-known. This study investigates the impact of five decades of land-use changes in potential ecosystem services (ESs) supply, in the peri-urban Ribeira dos Covões catchment, located in the periphery of Coimbra one of the largest cities in central Portugal. Based on eight land-use maps from 1958 to 2012, the ESs were estimated through a quantification matrix developed by local stakeholders. The expansion of urban and forest areas from 7% to 40% and from 43% to 55%, respectively, mostly through the occupation of agriculture fields (reduced from 48% to 4%), together with changes in the type of forest area (from mixed to commercial broad-leaved), led to a 73% reduction in the ESs potential supply. This reduction was driven by major losses in regulation but also provisioning services. Catchment management and urban planning should be supported by ESs assessment in order to mitigate the negative impacts on regulation, provisioning and cultural services provided by the ecosystems, and thus maximize the benefits for society.

Evaluation of oxidative DNA lesions in plasma and nuclear abnormalities in erythrocytes of wild fish (Liza aurata) as an integrated approach to genotoxicity assessment.

Genetic lesions (8-hydroxy-2'-deoxyguanosine (8-OHdG) and erythrocytic nuclear abnormalities (ENA) were seasonally quantified in the blood of Liza aurata caught at Ria de Aveiro (Portugal), a multi-contaminated aquatic system. Thus, five critical sites were assessed and compared with a reference site (Torreira). Oxidative DNA damage was found in Gafanha (harbour-water area), Laranjo (metal-contaminated) and Vagos (contaminated with PAHs) in the spring; Rio Novo do Principe (near a former paper-mill effluent) in the autumn; Rio Novo do Principe and Vagos in the winter. ENA were higher than Torreira at VAG (spring and winter). Torreira did not display seasonal variation neither in terms of 8-OHdG or total ENA. A positive correlation between 8-OHdG and ENA was found, suggesting oxidative stress as a mechanism involved in the formation of ENA. This study clearly demonstrates the presence of DNA-damaging substances in Ria de Aveiro and recommends the use of 8-OHdG and ENA as biomarkers of environmental contamination.