Shifts in coralline algae, macroalgae, and coral juveniles in the Great Barrier Reef associated with present‐day ocean acidification

Seawater acidification from increasing CO2 is often enhanced in coastal waters due to elevated nutrients and sedimentation. Our understanding of the effects of ocean and coastal acidification on present‐day ecosystems is limited. Here we use data from three independent large‐scale reef monitoring programs to assess coral reef responses associated with changes in mean aragonite saturation state (Ωar) in the Great Barrier Reef World Heritage Area (GBR). Spatial declines in mean Ωar are associated with monotonic declines in crustose coralline algae (up to 3.1‐fold) and coral juvenile densities (1.3‐fold), while non‐calcifying macroalgae greatly increase (up to 3.2‐fold), additionally to their natural changes across and along the GBR. These three key groups of organisms are important proxies for coral reef health. Our data suggest a tipping point at Ωar 3.5–3.6 for these coral reef health indicators. Suspended sediments acted as an additive stressor. The latter suggests that effective water quality management to reduce suspended sediments might locally and temporarily reduce the pressure from ocean acidification on these organisms.

Smith J. N., Mongin M., Thompson A., Jonker M. J., De’ath G. & Fabricius K. E., in press. Shifts in coralline algae, macroalgae, and coral juveniles in the Great Barrier Reef associated with present‐day ocean acidification. Global Change Biology. Article (subscription required).

0 Responses to “Shifts in coralline algae, macroalgae, and coral juveniles in the Great Barrier Reef associated with present‐day ocean acidification”



  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.




Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,357,391 hits

OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book