Trace elements in loggerhead turtles (Caretta caretta) stranded in mainland Portugal: Bioaccumulation and tissue distribution

• Published in: Chemosphere
• Main Authors: Nicolau, Lídia, Monteiro, Sílvia S., Pereira, Andreia T., Marçalo, Ana, Ferreira, Marisa, Torres, Jordi, Vingada, José V., Eira, Catarina
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 1 2017
• Subjects: Animals; Cadmium; Diet; Environmental Monitoring; Kidney; Liver; Portugal; Spain; Tissue Distribution; Trace Elements; Water Pollutants; Chemical; Turtles; Bioaccumulation; Marine turtle; Northeast Atlantic; Ciências Naturais::Ciências Biológicas; Science & Technology
• Online Access: https://hdl.handle.net/1822/51638; https://doi.org/10.1016/j.chemosphere.2017.03.108

Pollution is among the most significant threats that endanger sea turtles worldwide. Waters off the Portuguese mainland are acknowledged as important feeding grounds for juvenile loggerheads. However, there is no data on trace element concentrations in marine turtles occurring in these waters. We present the first assessment of trace element concentrations in loggerhead turtles (Caretta caretta) occurring off the coast of mainland Portugal. Also, we compare our results with those from other areas and discuss parameters that may affect element concentrations. Trace element concentrations (As, Cd, Cu, Pb, Mn, Hg, Ni, Se, Zn) were determined in kidney, liver and muscle samples from 38 loggerheads stranded between 2011 and 2013. As was the only element with higher concentrations in muscle (14.78 μg g-1ww) than in liver or kidney. Considering non-essential elements, Cd presented the highest concentrations in kidney (34.67 μg g-1) and liver (5.03 μg g-1). Only a weak positive link was found between renal Cd and turtle size. Inter-elemental correlations were observed in both liver and kidney tissues. Hepatic Hg values (0.30 ± 0.03 μg g-1) were higher than values reported in loggerheads in the Canary Islands but lower than in Mediterranean loggerheads. Cd concentrations in the present study were only exceeded by values found in turtles from the Pacific. Although many endogenous and exogenous parameters related with complex life cycle changes and wide geographic range may influence trace element accumulation, the concentrations of Cd are probably related to the importance of crustaceans in loggerhead diet in the Portuguese coast. Sociedade Portuguesa de Vida Selvagem for their assistance with data and sample collection and the staff at the Centres Científics i Tècnics of the Universitat de Barcelona. The authors also thank the Oceanário de Lisboa for their support. LN, MF and AM were supported by the Portuguese Foundation for Science and Technology (FCT) grants (SFRH/BD/51416/2011, SFRH/BD/30240/2006, ...