Fish-farming bolsters algal fouling and negatively affects condition and reproduction in European pond turtles (Emys orbicularis)
- 22 March 2021
- journal article
- research article
- Published by Springer Science and Business Media LLC in The Science of Nature
- Vol. 108 (2), 1-8
- https://doi.org/10.1007/s00114-021-01723-3
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.Keywords
Funding Information
- Agence de l'eau Loire-Bretagne
- WWF
- Réserve Naturelle Nationale de Chérine
- CNRS
This publication has 41 references indexed in Scilit:
- Carapacial Shell Disease Process Revealed by a Long-term Field Study of the Yellow Mud Turtle, Kinosternon flavescens, in TexasJournal of Herpetology, 2020
- High Incidence of Filamentous Algae on Western Pond Turtles,Actinemys marmorata, in the Willamette Valley, OregonNorthwestern Naturalist, 2015
- Deleterious effects of the ciliate epibiont Zoothamnium sp. on fitness of the copepod Acartia tonsaJournal of Plankton Research, 2014
- Impact of Eutrophication on the Seagrass Assemblages of the Mondego Estuary (Portugal)Published by Springer Science and Business Media LLC ,2010
- Assessment of the environmental impact of carnivorous finfish production systems using life cycle assessmentJournal of Cleaner Production, 2009
- Epizoochory, Algae and the Australian Eastern Long-Necked Turtle Chelodina Longicollis (Shaw)The American Midland Naturalist, 2008
- Thermoregulation When The Growing Season Is Short: Sex-Biased Basking Patterns in a Northern Population of Painted Turtles (Chrysemys Picta)Journal of Herpetology, 2008
- Human‐induced eutrophication enhances reproductive success through effects on parenting ability in sticklebacksOikos, 2007
- Evidence of a mutualistic relationship between an algal epibiont and its host, Daphnia pulicariaLimnology and Oceanography, 2001
- Individual and population level consequences of an algal epibiont on DaphniaLimnology and Oceanography, 1993