Warming has a greater effect than elevated CO₂on predator–prey interactions in coral reef fish

Abstract

Ocean acidification and warming, driven by anthropogenic CO emissions, are considered to be among the greatest threats facing marine organisms. While each stressor in isolation has been studied extensively, there has been less focus on their combined effects, which could impact key ecological processes. We tested the independent and combined effects of short-term exposure to elevated CO and temperature on the predator-prey interactions of a common pair of coral reef fishes ( and its predator, ). We found that predator success increased following independent exposure to high temperature and elevated CO Overall, high temperature had an overwhelming effect on the escape behaviour of the prey compared with the combined exposure to elevated CO and high temperature or the independent effect of elevated CO Exposure to high temperatures led to an increase in attack and predation rates. By contrast, we observed little influence of elevated CO on the behaviour of the predator, suggesting that the attack behaviour of was robust to this environmental change. This is the first study to address how the kinematics and swimming performance at the basis of predator-prey interactions may change in response to concurrent exposure to elevated CO and high temperatures and represents an important step to forecasting the responses of interacting species to climate change.

Ocean warming has a greater effect than acidification on the early life history development and swimming performance of a large circumglobal pelagic fish

“…Conversely, temperature did not affect the distance moved, but increased the maximum speed and reduced latency, potentially linked to the advanced developmental stage of fish at 25°C, even when the greater size of the fish at 25°C was accounted for. Similar results have been found recently in coral reef fish, where escape responses in predator-prey interactions were affected more by elevated temperature than elevated pCO 2 (Allan, Domenici, Watson, Munday, & McCormick, 2017). These results show that elevated temperature and pCO 2 can interact in complex ways to alter the escape responses of larval fishes.…”

Synchronous behavioural shifts in reef fishes linked to mass coral bleaching

“…However, these experiments are overwhelmingly focused on the direct effects of water temperature and acidification e.g., 14 , despite the more immediate threat from on-going loss of coral 15 . Moreover, these experiments focus on the short-term responses of only a handful of species to single stressors in aquaria isolated from community interactions.…”

Effect of elevated CO2and small boat noise on the kinematics of predator–prey interactions

“…Results of this and other studies that have looked at the combined effects of stressors on predator-prey dynamics emphasize that the outcome of the interaction depends strongly not only on the way each species is affected by the stressor, but also their motivation to respond (e.g. [44]).…”

“…Predator-prey interactions were measured using the standard protocol established by Allan et al [40,44]. Briefly, this involved placing a predator and prey fish into an experimental white polypropylene tank (Nally IH051, 645 Â 413 Â 276 mm, 10 cm water height; 2.5 mm wall thickness), with a predator being placed in the main elliptical arena (1452 cm 2 ) and prey in a 50 mm diameter grey pipe.…”