Experts Now Agree: Acropora Coral at Stone Island

APPARENTLY the Nature article I quote from in my new first film Beige Reef doesn’t claim there is no longer any Acropora at Stone Island. According to Graham Readfearn, writing today in The Guardian, I got it wrong.

In fact, he’s got it wrong.

Following are more direct quotes from the same Nature paper:

“Using a combination of anecdotal, ecological and geochemical techniques, the results of this study provide a robust understanding of coral community change for Bramston Reef and Stone Island.”

“At Stone Island, the reef crest was similar to that observed in 1994 with a substrate almost completely devoid of living corals.”

“For Stone Island, the limited evidence of coral growth since the early 19th Century suggests that recovery is severely lagging.”

“… by 1994 the reef was covered in a mixture of coral rubble and algae with no living Acropora and very few massive coral colonies present …”

The Nature article got it so wrong because the two transects were run across a section of reef where the corals are now dead, as I’ve explained in previous blog posts. The transect was run across the dead coral in front of our little boat as shown in the feature picture at the top of this blog post. At this reef, the live coral is at the reef’s edge, shown behind our boat in the picture. That edge of live coral runs for about two kilometres at varying widths around the south-western edge of Stone Island.

Following is the email I wrote to the journalist, Graham Readfearn yesterday with my four responses to his four questions.

Hi Graham,

Thank you for your email concerning my first film, Beige Reef. I reply to your four questions as inserts to your email, following.

By way of perspective, let me also comment that:

Beige Reef is a short film showing the condition and extent of an inshore coral reef that is part of the Great Barrier Reef.

We filmed this reef because, according to a scientific report in the journal Nature, there are no longer any Acropora corals at this location. The peer-reviewed article, coauthored by David Wachenfeld who is the chief scientist at the Great Barrier Reef Marine Park Authority, claims the corals at Stone Island have been destroyed by global warming and declining water quality.

Yet we found about 25 hectares of Acropora in the north-facing bay at Stone Island.

The underwater cinematography shown in this film is irreconcilable with the claims in the Nature article.

Beige Reef, my very first film, makes the point that Peter Ridd has been making for some time: that our scientific institutions are untrustworthy, that there is a need for some quality assurance of the science.

As a journalist I ask the you dispassionately consider the evidence, which should begin with you watching the film and then reading the article in Nature.

Kind regards
Jennifer Marohasy

1. In your video, you say that Dr Clark’s paper says there are “no living acropora colonies” at Stone Island. But Dr Clark says her paper did not say that, and in fact said there were some acroporas at the site of Saville-Kent’s original photographs. Clark says you have incorrectly placed emphasis on a 1994 finding from Wachenfeld, which is quoted in her paper. Your IPA colleague Gideon Rozner also repeats this claim in a promotional video.

RESPONSE FROM JENNIFER MAROHASY:

Clark et al. explain (page 11) that they took just two transects each of 20 metres at Stone Island. Based on this sampling they intended to categorized coral cover as ‘live hard coral’, ‘dead coral’, ‘soft coral’, ‘algae’, ‘other substratum’ (substrate and sediment), and ‘unknown’.

It is specifically stated that at Stone Island only nine dead corals were found along transects 1 and 2, and that these corals were covered in mud and algae.

2. Clark says that for Stone Island, her paper concentrated on the sites visited by Saville-Kent and Wachenfeld, which is a different location to much of your footage from a subtidal reef slope.

RESPONSE FROM JENNIFER MAROHASY:

Clark et al. explain (page 11) that only two short transects were taken because the reef environment was ‘highly consistent’. Based on these two transects Clark et al. draw conclusions about the situation at Stone Island in general. My first film is about Beige Reef that is just around the headland from the location of the two transects.

My second film will be about the reef to the south south-west of Stone Island. Here there is an extensive area of coral (including Acropora spp.) just metres from the two transects from which Clark et al draw erroneous conclusions.

3. Clark says that her 2016 paper did not make any claims about other areas of the reef and no “ill-fated prognosis” was made in that paper.

RESPONSE FROM JENNIFER MAROHASY:

Following is just some of what Clark et al write about the corals at Stone Island:

“Using a combination of anecdotal, ecological and geochemical techniques, the results of this study provide a robust understanding of coral community change for Bramston Reef and Stone Island.”

“At Stone Island, the reef crest was similar to that observed in 1994 with a substrate almost completely devoid of living corals.”

“For Stone Island, the limited evidence of coral growth since the early 19th Century suggests that recovery is severely lagging.”

“… by 1994 the reef was covered in a mixture of coral rubble and algae with no living Acropora and very few massive coral colonies present …”

4. In the video you say you could not see any bleaching – yet Dr Clark says this is not surprising, because regardless, you visited in August 2019 – more than two years after the previous major bleaching episode.

RESPONSE FROM JENNIFER MAROHASY:

I am delighted that Tara Clark acknowledges that there is no bleaching of corals at Stone Island. I would like to film coral bleaching at the Great Barrier Reef, but no-one has been able to tell me where I can find bleached corals. I would be happy to travel to any location at the Great Barrier Reef that shows significant bleaching for a future IPA short film. Could you, and/or Tara Clark could provide me with specific locations.

Watch the short film, Beige Reef: