Morphological variations and demographic responses of the Mediterranean pond turtle Mauremys leprosa to heterogeneous aquatic habitats

• Published in: The Science of the total environment 2024-06, Vol.927, p.172077-172077, Article 172077
• Main Authors: Le Gal, Anne-Sophie, Georges, Jean-Yves, Sotin, Christine, Charrière, Bruno, Verneau, Olivier
• Format: Article
• Language: English
• Subjects: Animal biology; Animals; Biodiversity and Ecology; Ecosystem; Ecotoxicology; Environmental Monitoring; Environmental Sciences; France; Freshwater turtles; Life Sciences; Ponds; Population structure; Toxicology; Turtles - physiology; Vertebrate Zoology; Wastewater treatment plant; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - toxicity; Water pollution
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.172077

Human activities affect terrestrial and aquatic habitats leading to changes at both individual and population levels in wild animal species. In this study, we investigated the phenotype and demographics of the Mediterranean pond turtle Mauremys leprosa (Schweigger, 1812) in contrasted environments of Southern France: two peri-urban rivers receiving effluents from wastewater treatment plants (WWTP), and another one without sewage treatment plant. Our findings revealed the presence of pesticides and pharmaceuticals in the three rivers of investigation, the highest diversities and concentrations of pollutants being found in the river subsections impacted by WWTP effluents. Principal component analysis and hierarchical clustering identified three levels of habitat quality, with different pollutant concentrations, thermal conditions, nutrient, and organic matter levels. The highest turtle densities, growth rates, and body sizes were estimated in the most disturbed habitats, suggesting potential adult benefits derived from harsh environmental conditions induced by pollution and eutrophication. Conversely, juveniles were the most abundant in the least polluted habitats, suggesting adverse effects of pollution on juvenile survival or adult reproduction. This study suggests that turtles living in polluted habitats may benefit from enhanced growth and body size, at the expense of reproductive success. [Display omitted] •Phenotypes and population structure of Mauremys leprosa are influenced by water quality.•Fast-growing turtles, as well as largest and heaviest males, are associated with the most polluted habitats.•Highest proportions of juveniles are associated with the least polluted habitats.•Eutrophication affects turtle phenotype and may adversely affect reproductive success.