The effects of climate change on fish reproduction
Since 2011, the ECOBIOP research unit has been running a cross-border research project on the effects of the hydrological consequences of climate change on salmonid behaviour.
Climate change has many effects. In collaboration with the NuMeA research unit and the biology department of the University of the Basque Country in Bilbao, the ECOBIOP research unit (INRA/UPPA) has decided to investigate the effects of extreme hydrological events on the reproductive behaviour of fish in rivers. “We are particularly interested in the consequences of variations in flow, linked for example to a flood or a period of serious drought”, explains Jacques Labonne, responsible for research at the Saint-Pée-sur-Nivelle site. “We want to understand how sudden variations in flow affect the fishes’ investment in reproduction and to evaluate their ability to adapt.”
The researchers are using the experimental site at Lapitxuri in the commune of Aïnhoa, an installation unique in Europe consisting of an artificial spawning channel 130 m long and 3 m wide where the flow rate of the water can be adjusted. It is equipped with an underwater observation post and video cameras.
From 2011 to 2014 a cross-border grant to Zoé Gauthey, completed by funds from INTERREG AARC and the MIRA Federation, enabled the development of an experimental study into sexual selection in the common trout, using specially-adapted experimental protocols and statistical models. On this occasion, thanks to the collaboration of NuMeA, new methods were developed for measuring the physiological status of the fish. Zoé Gauthey’s work demonstrated a decrease in the females’ reproductive investment in the case of variable flow, and showed that the increase in the frequency of extreme hydrological events exercises a selection pressure favouring certain phenotypes. Supervised by Agnès Bardonnet (UPPA) and Aitor Larrañaga (UPV), postdoctoral student Elorri Arevalo took over in 2014, studying the trophic relationships between juvenile trout and their prey.
“The idea is to precisely measure the impact of the spring floods on feeding in young fish”, summarises Jacques Labonne. Elorri Arevaloshould benefit from the help of Lorea Flores,an AgreenSkills postdoctoral student at the INRA, recruitedto work in collaboration with theuniversities of Bilbao and Gerona on the“ecosystem services” aspect,i.e. the impact of floods interms of gains and losses for aquatic ecosystems.
Contact: Jacques Labonne, jacques.labonne @ univ-pau.fr (jacques.labonne @ univ-pau.fr)