Thursday, March 25, 2010

Lord Howe Island Corals: reports of our death greatly exaggerated.

COMMENT: Southern Cross University (SCU) issued a press release dated 24 March 2010 describing a coral bleaching event on Lord Howe Island due to unusual weather conditions (warmer sea water temperature, low wind and cloud cover...the effects of the current El Nino perhaps?) in early 2010. The press release must have been provided some time earlier to ABC's environment reporter Sarah Clarke whose subsequent reports including interviews with SCU's Prof Peter Harrison and some handy on-site footage of Lord Howe Island was released on Radio National's AM at around 7.30 am EDST.
Sarah Clarke managed to spread the news far and wide providing near saturation coverage across all ABC formats.
AM-"Warmer waters bleach Lord Howe's unique reef"
Science Online: Bleaching leaves Lord Howe reef on 'knife edge'
TV:ABC 7.00 news SYDNEY Lord Howe Island reef succumbs to bleaching
News Online: Bleaching leaves Lord Howe reef on 'knife edge'
Radio Australia: "Warmer waters bleach Lord Howe's unique reef"
Links to the story were also featured prominently on ABC's home page. The reports feature photos provided by Prof. Harrison.

We note that Prof Harrison and Sarah Clarke are not strangers and have "collaborated" together in the past, for instance on this story for the 7:30 Report in November 2007 "Busting the Scientific Whaling Myth". Perhaps this explains Ms Clarke's early access to the SCU press release.

The story emphasised the unique nature of the reefs at Lord Howe and their susceptibility to climate change. What the reports failed to mention was that a study published in the journal Global and Planetary Change in 2005 titled "Episodes of reef growth at Lord Howe Island, the southernmost reef in the southwest Pacific" (Volume 49: 222-237) by Woodroffe et al., found a long history of coral reefs at Lord Howe Island with sporadic reef development extending well back into the Pleistocene. Woodroffe et al. note:

"Although the modern fringing reef on the western side of Lord Howe Island supports luxuriant coral
communities (Veron and Done, 1979; Harriott et al., 1995), coring and dating of lagoonal sediments imply a phase of more prolific coral growth and sediment production in the mid-Holocene (Kennedy and Woodroffe, 2000). This coincides with a time at which higher temperatures have been indicated by isotopic proxies in corals on the Great Barrier Reef (Gagan et al., 1998), and in worm tubes in eastern Australia (Baker et al.,2001). It remains unproven, however, whether sea-surface temperatures were higher at Lord Howe Island. An alternative explanation is that there was a broad expanse
of suitable substrate available as the sea rose across the bench bevelled into calcarenites that had been deposited during a previous interstadial." 
It seems to us that it was probably a combination of factors of warmer temperatures and available space that provided the conditions for more prolific coral growth in the mid-Holocene, we wait the results of further research. Regardless, the geological evidence shows that coral reefs have managed to adapt to a range of climatic and sea level conditions at Lord Howe Island and in this context the current bleaching event is likely to be just one of a multitude of events in the reef's past, many of which were probably much more dramatic and dire than the current one. 

The ABC reports included a number of statements by Lord Howe Island Marine Park manager Ian Kerr, but oddly this one from SCU's press release failed to get a mention in any of the ABC coverage: “ I've seen aerial photographs and I’m pleased to report the beauty and uniqueness of the reef is still intact, we remain very concerned about this event and will continue to facilitate the research and monitoring that needs to continue,” Mr Kerr said.

With this in mind it seems reports that reefs at Lord Howe are "on a knife's edge", are somewhat exaggerated, unless of course that knife has a very dull edge. 

The late Richard Feynman stated in a speech at Caltech on the subject of Cargo cult Science "In summary, the idea is to give all of the information to help others to judge the value of your contribution; not just the information that leads to judgement in one particular direction or another." This applies not only to science, but also I think, to science reporting in order to avoid cargo cult journalism.

Cargo cult journalism evident in this SMH story on the Bay of Bengal and now in this ABC report "Island vanishes under the sea"  No mention in either article of a little something called subsidence.

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