Seagrass habitats not neccesarily a place of refuge for future coral populations

Embargoed until: Publicly released:

Research aimed at understanding whether corals that live in dynamic habitats adjoining coral reefs, such as seagrass beds, are better acclimatised to tolerate future environmental change, raises questions about the ability of these habitats to act as a coral refuge. The research showed that acclimatisation to habitats that experience large daily changes in temperature and pH doesn't enhance tolerance of two key Caribbean corals to predicted future climate scenarios.

Journal/conference: Proceedings of the Royal Society B

Organisation/s: University of Technology Sydney (UTS)

Funder: ARC Future Fellowship

An international research team examined how pH and temperature levels, predicted for the next century, affected the growth and physiology of two dominant Cayman Island corals, Acropora palmata and Porites astreoides. Both species inhabit the outer reef where environmental conditions remain relatively stable throughout the day while P. astreoides is also found in adjacent shallow lagoon habitats that also contain seagrass beds. This latter high variance environment routinely exposes coral to conditions predicted for reefs over the next 50 – 100 years.

“Coral reefs worldwide are increasingly under threat from ocean warming and acidification. Habitats with inherently high-variance temperature and pH conditions have been proposed as a potential refuge for corals from climate change,” says lead author Dr Emma Camp from the University of Technology Sydney (UTS), Climate Change Cluster.

“However our research doesn’t support this. Instead we show that calcification, the fundamental process dictating coral growth, was impacted equally by future open ocean climate scenarios for populations from high-variance seagrass and low-variance reef habitats.”

The researchers point out that under present day conditions the seagrass habitat provides a “buffering service” against decreasing calcification rates. However, if over time these highly variable systems experience the same level of environmental change as the rest of the reef, as seems likely, then any advantage acclimatised corals have won’t offset the detrimental impacts caused by ocean warming and acidification.

Although both coral species experienced the same net decrease in calcification the research team observed that the physiological mechanisms driving the decline were very different, warranting further investigation.

Apart from scientists from UTS the collaboration also included scientists from the Universities of Essex and Miami and NOAA. ARC Future Fellowship funding supported Associate Professor David Suggett’s involvement in the research. Associate Professor Suggett leads the Future Reefs research program at UTS.

Publication details:

Camp E, Smith DJ, Evenhuis C, Enochs I, Manzello D, Woodcock S, Suggett DJ. 2016 Acclimatization to high-variance habitats does not enhance physiological tolerance of two key Caribbean corals to future temperature and pH. Proc. R. Soc. B 20160442.

http://dx.doi.org/10.1098/rspb.2016.0442

Attachments:

  • The Royal Society
    Web page
    Link will go live sometime after the embargo lifts

News for:

Australia
NSW

Multimedia:

  • Cayman Island Coral Reef
    Cayman Island Coral Reef

    Caribbean reefs can be quite barren in places when compared to the Great Barrier Reef

    File size: 150.2 KB

    Attribution: Dr Emma Camp, University of Technology Sydney

    Permission category: Free to share (must credit)

    Last modified: 03 Nov 2016 8:06pm

    NOTE: High resolution files can only be downloaded here by registered journalists who are logged in.

  • Cayman Island Coral Reef  - Little Cayman
    Cayman Island Coral Reef - Little Cayman

    Compared to the Great Barrier Reef some Caribbean Reefs have a lot less diversity and can be quite barren in places

    File size: 117.2 KB

    Attribution:

    Permission category: Free to share (must credit)

    Last modified: 03 Nov 2016 8:15pm

    NOTE: High resolution files can only be downloaded here by registered journalists who are logged in.

Show less
Show more

Media contact details for this story are only visible to registered journalists.