Influence of temperature on surface sediment disturbance by freshwater fish: a microcosm experiment

¹ Université de Toulouse, INP, UPS, EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement), ENSAT, Avenue de l'Agrobiopole, 31326 Castanet Tolosan, France
² CNRS, EcoLab, 31326 Castanet Tolosan, France
³ Université de Toulouse, UPS, INP, EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement), 118 route de Narbonne, 31062 Toulouse Cedex 9, France
⁴ CNRS, EcoLab, 31055 Toulouse, France
⁵ UMR 5174 EDB (Laboratoire Evolution et Diversité Biologique), CNRS, 31062 Toulouse, France
⁶ Université de Toulouse, UPS, EDB, 118 route de Narbonne, 31062 Toulouse, France

^* Corresponding author: laetitia.buisson@univ-tlse3.fr

Received: 11 July 2014
Accepted: 27 March 2015

Abstract

Water temperature is a key parameter that regulates activities of ectotherms (e.g., fish) and has been projected to rise in the future in the context of climate change. Surface sediment disturbance (SSD) is an important function performed by fish that modifies benthic habitat properties and may thus influence ecosystem functioning. However, the link between SSD by fish and temperature remains unexplored. In this study, we experimentally assessed the influence of two contrasted temperatures (10 versus 20°C) on SSD by three freshwater fish species in aquaria. After 10 days, the total surface disturbed by the species was approximately 2–3 times higher at warm than at cold temperature but the number and area of patches disturbed by the species were not significantly different. The stone loach Barbatula barbatula, a benthic fish species, had a higher SSD activity (i.e., total surface disturbed, number and size of patches disturbed) both at cold and warm temperatures than two cyprinid species, chub Squalius cephalus and sofie Parachondrostoma toxostoma. On average, SSD by B. barbatula resulted in approximately two and three more patches than the cyprinid species at 10 and 20°C, respectively, and the mean patch area disturbed by B. barbatula was about two times larger than the ones disturbed by the cyprinid species. The total surface disturbed by the cyprinids at warm temperature was roughly equivalent to the surface disturbed by B. barbatula at cold temperature. Our results thus suggest that SSD by fish could increase in future warmed conditions.