Impacts of ocean acidification and warming on seaweeds and algal turfs

Ocean Acidification setup, small, Marine

Ocean Acidification setup, small, Marine

Coral reef degradation is generally associated with increases in the abundance of algal turfs and seaweeds. With the recent problem of human-induced ocean acidification there is increasing concern that these types of algae may benefit from environmental conditions projected for the near future and continue proliferating and invading reefs. However, little is known about the impacts of increased CO2 concentrations on the physiology and growth of tropical seaweeds and algal turfs. To address this issue we are currently investigating the responses of algal turfs and seaweeds to increased seawater CO2 levels and warming in controlled experimental manipulations in the Great Barrier Reef.

 

Halimeda small, Respirometry

Halimeda small, Respirometry

Our preliminary results indicate that algal turfs are quite resilient to the impacts of increased CO2. The responses of seaweeds are highly variable and depend on the type of seaweeds and their physiological mechanisms to acquire CO2. For example, the growth of the calcareous green algae Halimeda declined under acidified conditions, while growth of some brown seaweeds increased. Understanding the cause of such variability is a major focus of our lab.

 

Current Projects:

  • Responses of algal turfs to ocean acidification and warming in Lizard Island, GBR. PhD student Dorothea Bender, The University of Queensland.
  • Changes in algal turf assemblages under enhanced CO2 conditions at Heron Island. Collaboration with PhD student Gordon Obber, University of Rhode Island.
  • 2008-2011, Multi-scale analysis of the vulnerability of coral reefs to ocean acidification, ARC Linkage (Anthony, Hoegh-Guldberg, Diaz-Pulido, et al.).