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Costa R.A.,University of Minho | Eeva T.,University of Turku | Eira C.,Sociedade Portuguesa de Vida Selvagem | Eira C.,University of Aveiro | And 4 more authors.
Chemistry and Ecology | Year: 2014

Passerine species have been increasingly used as monitors of metal pollution, especially by making use of non-destructive indicators of bird exposure, such as collecting feathers, faeces or blood. During this study, mercury concentrations were determined in feathers, faeces and blood of nestling great tits (Parus major) in industrial (a paper mill) and rural sites on the west coast of Portugal. The aim of this study was to compare the level of mercury in both areas over the study period, as indicated by nestlings' mercury levels, while assessing possible contamination effects on the breeding performance and health status of great tits. Over the years, feathers showed a significant annual decrease in mercury contamination in the study area. Blood analyses also revealed a significant annual decrease in mercury concentrations, but no significant differences were detected between areas. Faeces data showed no significant difference between years or areas. We found no direct influence of mercury levels on nestling health status or great tit breeding performance. © 2014 Taylor & Francis.


Costa R.A.,University of Minho | Eeva T.,University of Turku | Eira C.,Sociedade Portuguesa de Vida Selvagem | Eira C.,University of Aveiro | And 3 more authors.
Archives of Environmental Contamination and Toxicology | Year: 2012

This long-term study (2003-2010) compared the breeding parameters of great tits living in a paperand- pulp-industry area to those of great tits living in a rural area on the west coast of Portugal. We also measured the abundance of caterpillar biomass, an important food source and determinant of breeding success for tits. In 2009, we further analysed trace metal [arsenic (As), calcium (Ca), cadmium, copper, mercury (Hg), nickel, lead, selenium, and zinc] as well as Ca concentrations in excrement of 15-day-old great tit nestlings. Generally, for most trace metals, fecal concentrations were similar at both sites. Nonetheless, greater Hg levels and lower As levels were detected in the industrial area. Great tits laid more eggs and produced more fledglings in the industrial area than in the rural area. Caterpillar biomass was also greater in the industrial area, which likely explains the better breeding success. Our results suggest that there are no direct effects of emissions on the studied species. © Springer Science+Business Media, LLC 2012.


Costa R.A.,University of Minho | Eeva T.,University of Turku | Eira C.,Sociedade Portuguesa de Vida Selvagem | Eira C.,University of Aveiro | And 3 more authors.
Environmental Monitoring and Assessment | Year: 2013

Passerine species have been increasingly used as bioindicators of metal bioaccumulation especially by taking benefit of non-invasive procedures, such as collecting feathers and excrements. In 2009, metal (As, Cd, Cu, Hg, Ni, Pb, Se and Zn) concentrations were determined in feathers and excrements of nestling and adult female great tits (Parus major) in industrial (a paper mill) and rural sites in maritime pine forests on the west coast of Portugal. The aim of this study was to compare the levels of metals between the areas but also between sampling methods (feather vs. excrement) and age classes (nestling vs. adult). Although excrements and feathers of nestling great tits showed different concentrations, similar patterns of accumulation were detected in both study areas. There was a significantly higher concentration of mercury in the industrial area and significantly higher concentrations of arsenic in the rural area in both sample types. Metal levels in adult females had quite different results when compared to nestlings, and only nickel presented significantly higher levels near the paper mill. Since metal levels showed a consistent pattern in feathers and excrements of nestling great tits, we conclude that both represent good and non-invasive methods for the evaluation of these elements in polluted areas. © 2012 Springer Science+Business Media Dordrecht.


Costa R.A.,University of Minho | Eeva T.,University of Turku | Eira C.,Sociedade Portuguesa de Vida Selvagem | Eira C.,University of Aveiro | And 3 more authors.
Ecoscience | Year: 2011

Air pollution has been found to have direct and indirect effects on forest passerines, but there is very little information on the effects of emissions from the pulp and paper industry. This long-term (7 y) study compares breeding parameters of Great tits in industrial and rural sites in maritime pine forests on the west coast of Portugal. We found that Great tits bred earlier, laid more eggs, and produced more fledglings in the industrial area, where we also found a higher biomass of caterpillars, an important food source for tits. There were also differences in ground arthropod numbers, the industrial area having more beetles and millipedes and the rural area more spiders and silverfish. Our results suggest that there are no direct toxic effects of emissions from the paper industry on the study species. However, invertebrate food availability is clearly related to pollution levels, which indirectly affect the breeding performance of the Great tit.


Oliveira N.,SPEA | Henriques A.,Sociedade Portuguesa de Vida Selvagem | Miodonski J.,Sociedade Portuguesa de Vida Selvagem | Pereira J.,SPEA | And 13 more authors.
Global Ecology and Conservation | Year: 2015

Competition with fisheries and incidental capture in fishing gear are the major current threats for seabirds at sea. Fishing is a traditional activity in Portugal and is mainly composed of a great number of small vessels. Given the lack of knowledge on effects of the Portuguese fishing fleet on seabird populations, bycatch was assessed in mainland coastal waters for 2010-2012. Interviews and on-board data were divided into 5 strata, according to fishing gear: Bottom trawling, Bottom longline, Purse seine, Beach seine, Polyvalent (≥12 m) and Polyvalent (<12m). Polyvalent included Setnets, Traps and Demersal longlines. Overall, 68 birds were recorded to be bycaught. The average catch per unit effort (CPUE) was 0.05 birds per fishing event. Polyvalent (<12m), Polyvalent (≥12 m) and Purse seiners had the biggest seabird bycatch rates, with 0.5 (CPUE=0.1), 0.11 (CPUE=0.05) and 0.2 (CPUE=0.11) birds per trip, respectively. Within Polyvalent gear, Setnets captured the largest diversity of seabird species (CPUE=0.06), while Demersal longline had the highest CPUE (0.86). Northern gannet was the most common bycaught species. Although more observation effort is required, our results suggest that substantial numbers of Balearic shearwater might be bycaught annually, mainly in Purse seine and Setnets. © 2014 The Authors.

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