Affordable Access

Access to the full text

Fish-farming bolsters algal fouling and negatively affects condition and reproduction in European pond turtles (Emys orbicularis)

Authors
  • Beau, Frédéric1, 2
  • Brischoux, François1
  • 1 CEBC UMR 7372 CNRS-Université de La Rochelle, Villiers en Bois, 79360, France , Villiers en Bois (France)
  • 2 Maison de la Nature et de la Réserve, Saint-Michel-en-Brenne, 36290, France , Saint-Michel-en-Brenne (France)
Type
Published Article
Journal
The Science of Nature
Publisher
Springer Berlin Heidelberg
Publication Date
Mar 22, 2021
Volume
108
Issue
2
Identifiers
DOI: 10.1007/s00114-021-01723-3
Source
Springer Nature
Keywords
License
Yellow

Abstract

Fish-farming can lead to eutrophication of freshwater environments through the increase in organic matter resulting from food supplementation and fish wastes. Eutrophication can induce an excessive development of plants and algae on various substrates, including living organisms (algal epibiosis). Although algal epibiosis has been shown to reduce mobility by increasing drag in marine species, its consequences on host species in freshwater ecosystems remain poorly known. In this study, we investigated the individual (age and sex) and environmental (extensive versus intensive fish-farming) determinants of epizoic algae presence and abundance on European pond turtles (Emys orbicularis). We also explored the potential consequences of algal epibiosis on fitness-related traits of E. orbicularis. Based on a large sample size (1112 turtles from 23 ponds), we found that the abundance of algae growing on turtles increased during spring and summer. However, such increase was different across ages and sex; presumably reflecting the influence of thermoregulation (required to increase metabolic rates to sustain growth and reproduction) and thus, periodical drying of the shell, in reducing algal cover. We also found that intensive fish-farming increased algal epibiosis, especially when fish-farming involved food supplementation. Finally, we found that adult female body condition and reproduction of turtles were negatively linked to algal cover, thereby suggesting a potential negative impact of algal fouling on some fitness-related traits of adult female turtles. Future studies should usefully assess the demographic consequences of algal epibiosis induced by fish farming in this long-lived vertebrate.

Report this publication

Statistics

Seen <100 times