Effects of elevated carbon dioxide on reef fishes

Rising levels of carbon dioxide in the atmosphere means that more CO2 dissolves into the oceans, making it more acidic. Much pioneering research has been done at LIRS in recent years to determine the effect of that different water chemistry on reef fishes. At ocean pH levels predicted for the end of this century, researchers have found that the behaviour of reef fishes changes in many ways - for example, they are attracted to the smell of predators rather than repelled by it.

Dr Sue-Ann Watson

One of the paper’s authors, Dr Sue-Ann Watson, at work in the LIRS lab. Photographer: © Lyle Vail

Image: Lyle Vail
© Lyle Vail

This paper provides a good summary of the research to date while rigorously testing the methodology used for those earlier studies:

Munday, P.L., M.J. Welch, B.J.M. Allan, S.-A. Watson, S.J. McMahon and M.I. McCormick, 2016. Effects of elevated CO2 on predator avoidance behaviour by reef fishes is not altered by experimental test water. PeerJ 4:e2501; DOI 10.7717/peerj.2501

Crown-of-Thorns Starfish can really see

Crown-of-Thorns Starfish (COTS) are voracious coral predators that are being culled on the Great Barrier Reef to protect corals. By understanding how these starfish sense their environment to find their coral prey, we may be able to develop better methods for controlling them. It has long been known that starfish can detect light using an 'eye-spot' at the end of each arm but true image-forming vision had not been known to exist.

Crown-of-Thorns Starfish

Arm tip of a small Crown-of-Thorns Starfish on the underside. The eyespot is red. Photographer: © J.-P. Hobbs

Image: J.-P. Hobbs
© J.-P. Hobbs

The study described in the publication below used a combination of aquarium and field studies to show that COTS can actually form images. The authors suggest that COTS use smell to find their prey from a distance, then switch to visual as they get closer and the smell becomes less directional.

Petie, R., A. Garm and M.R. Hall, 2016. Crown-of-thorns starfish have true image forming vision. Frontiers in Zoology, 13: 41.