High-latitude, deep water coral bleaching at Rottnest Island, Western Australia

Author:

Thomson, Damian ; Bearham, Douglas ; Graham, Fiona; Eagle, Janelle

Date of Publication:

2011-11-23

Publication Type:

Journal Article

Journal Title:

Coral Reefs

Volume:

30

Issue:

4

Pages:

1107

Abstract:

Coral bleaching is well documented on shallow, tropical reefs, however, there are no published records of coral bleaching on high latitude (26 °), deep (20m) reefs. High latitude, deep water reefs are less affected by thermal stress and may therefore act as a potential refuge site from global warming (Bongaerts et al., 2010). Here, we observed extensive coral bleaching in May 2011 at two high-latitude (32° S) deep-water (24 - 28m) reefs located on the western side of Rottnest Island, off Perth, Western Australia. Most colonies of Coscinarea marshae (n ≈ 100), a species endemic to southern Australia, were completely bleached, while all other coral genera were unbleached. Water temperatures between December 2010 and May 2011 at these sites were higher than average and NOAA SST records reveal 16-degree heating weeks (DHW) for the region. In-situ measurements confirmed temperatures were up to 4°C higher than the long-term monthly average for the 150 days prior to surveys (27th Dec 2010 to 25th May 2011) and these above average temperatures extended to a depth of greater than 50m. Our observations confirm that corals located on deeper, high latitude reefs are susceptible to thermal bleaching. Interestingly, at this location C. marshae is close to the northern limit of its range (Veron and Marsh, 1988), which may explain why it is more susceptible to thermal stress than the other species at Rottnest, which all have populations extending further north (Veron and Marsh, 1988). High latitude endemics may therefore be more susceptible to global warming at these sites and deserving of a higher conservation status within this region.

Publisher:

Springer

Keywords:

Coral bleaching

Field Of Research:

Marine and Estuarine Ecology (incl. Marine Ichthyology)

DOI:

https://doi.org/10.1007/s00338-011-0811-x

URL:

Link to Publisher's Version

Rights Notice:

© 2011 Springer

Identifier:

EP113973

Publication Sub Type:

Journal article - Refereed

Language:

English

Attribution Statement:

Thomson, Damian; Bearham, Douglas; Graham, Fiona; Eagle, Janelle. High-latitude, deep water coral bleaching at Rottnest Island, Western Australia. Coral Reefs. 2011; 30(4):1107. https://doi.org/10.1007/s00338-011-0811-x