European sea bass show behavioural resilience to near-future ocean acidification.

M Duteil,G G De Polavieja,A J King,E C Pope,I Fürtbauer,M R Brown,A Pérez-Escudero

doi:10.1098/rsos.160656

Abstract

Ocean acidification (OA)—caused by rising concentrations of carbon dioxide (CO2)—is thought to be a major threat to marine ecosystems and has been shown to induce behavioural alterations in fish. Here we show behavioural resilience to near-future OA in a commercially important and migratory marine finfish, the Sea bass (Dicentrarchus labrax). Sea bass were raised from eggs at 19°C in ambient or near-future OA (1000 µatm pCO2) conditions and n = 270 fish were observed 59–68 days post-hatch using automated tracking from video. Fish reared under ambient conditions, OA conditions, and fish reared in ambient conditions but tested in OA water showed statistically similar movement patterns, and reacted to their environment and interacted with each other in comparable ways. Thus our findings indicate behavioural resilience to near-future OA in juvenile sea bass. Moreover, simulated agent-based models indicate that our analysis methods are sensitive to subtle changes in fish behaviour. It is now important to determine whether the absences of any differences persist under more ecologically relevant circumstances and in contexts which have a more direct bearing on individual fitness.

Highlights

Rising concentrations of carbon dioxide (CO2) in the atmosphere over the past 200 years have led to ocean acidification (OA) that threatens marine ecosystems [1,2,3]
There is a collective drive in the scientific community to better understand how future OA may impact upon marine fisheries and ecosystems [5]
Given that the laboratory environment could constrain fish behaviour, we built an artificial agent-based model of the experiment, which we compared with our experimental data, allowing us to gauge whether our analysis method is sensitive to subtle changes in fish behaviour

Summary

Introduction

Rising concentrations of carbon dioxide (CO2) in the atmosphere over the past 200 years have led to ocean acidification (OA) that threatens marine ecosystems [1,2,3]. Given the ecological and economic ramifications of positive or negative effects on commercially important marine fisheries, it is critical to investigate the behavioural effects of near-future oceanic conditions, using robust and relevant experiments to inform management strategies [6,7]. Recent work studying a variety of marine fish species has found both negative or neutral effects of nearfuture OA conditions on fish behaviour [10,11,12,13,14,15]. Such contradictory results may, at least in part, be explained by the different ways experiments are designed and conducted. This makes it difficult to disentangle OA effects from any behavioural alterations that are a response to any changed environment

Methods

Results

Conclusion