[Coral-List] pumice raft will not save the Great Barrier Reef

Wed Sep 4 22:21:40 UTC 2019

      I remember that the Great Barrier Reef (GBR) was long referred to as
one of the world's best managed coral reef systems.  Sadly, very sadly, but
no longer.  It probably has not been for quite a while, this is something
that was not recognized until relatively recently, but I don't think it is
a new situation.  Like for most of the world's reefs, not for lack of
trying, hard work by well-meaning people.  But society has not yet made the
commitments that are likely necessary.  Almost everywhere.
      I totally agree that we need to be realistic and accurate about what
has caused damage to coral reefs.  How can we fix things if we keep saying
the damage was caused by A when it was actually caused by B??  You have to
know the actual causes in order to correct problems, or else you waste
effort, time, and money on things that are not actually the cause of the
decline, and that means you are much less likely to be able to fix the
problem.
      The 2017 Consensus statement on the GBR Tomas points to says "The
systems have been severely impacted by a number of recent events—including
prolonged periods of extreme sea surface temperatures, tropical cyclones
and the progression of the fourth wave of crown-of-thorns starfish
population outbreaks."  It also says "The greatest water quality risks to
the Great Barrier Reef and coastal ecosystems are from discharges of (i)
nutrients, which are an additional stress factor for many coral species,
promote crown-of-thorns starfish population outbreaks with destructive
effects on mid-shelf and offshore coral reefs, and promote macroalgal
growth; (ii) fine sediments, which reduce the light available to seagrass
ecosystems and inshore coral reefs; and (iii) pesticides, which pose a
toxicity risk to freshwater ecosystems and some inshore and coastal
habitats."  I take the latter statement to mean that the risks are listed
in order, nutrients greatest, fine sediments second, and pesticides third,
probably in large part because the first has effects on the whole reef and
the latter two mainly on near-shore areas.  A published paper which appears
to be the published version of this (Kroon, et al, 2016) has been
referenced 44 times so far, according to Google Scholar.
      In addition, monitoring data from the GBR don't look as bad as they
did several years ago.  Bad news makes headlines, but good news is often
omitted, as readers are less interested.  As many of you probably know, as
of a few years ago, coral cover on the Great Barrier Reef had undergone a
drastic decline to levels closer to that of the Caribbean, astoundingly,
and of great concern.  Plus, now hot water bleaching has killed vast
numbers of corals in the northern part of the GBR in the last few years.
But I recommend looking at the most current results from the AIMS
monitoring program.  Check out the graphs and explanations (
https://www.aims.gov.au/reef-monitoring/gbr-condition-summary-2018-2019).
You'll see the northern section had no downward trend until the recent
bleaching events which produced a large decrease in coral cover, but looks
like recovery may (might) now have begun.  The central GBR shows a gradual
long term decline.  The southern GBR also shows a gradual long term
decline, but also a drastic decline that hit bottom in 2011 followed by a
complete recovery of coral cover from that drastic decline.  I believe the
drastic decline was due to the impacts of several tropical cyclones plus
crown of thorns outbreaks.  Maybe the GBR is more resilient than we
thought?  How long will it stay resilient????  Aren't we skating on thin
ice???
      This is NOT to say that the future for the GBR is rosy, or that it is
not being damaged, or that there have been no human impacts on the reef, or
that any reefs on the planet are safe from humans any longer.  Quite the
contrary.  But we need to acknowledge the reality of the mortality events,
the causes, and the trends in condition.
       An interesting further addition to the consensus statement:
"This is no time for hunches - we need evidence and expertise in science"
https://www.theguardian.com/commentisfree/2019/sep/04/this-is-no-time-for-hunches-we-need-evidence-and-expertise-in-science?utm_source=Nature+Briefing&utm_campaign=ecd3b87115-briefing-dy-20190904&utm_medium=email&utm_term=0_c9dfd39373-ecd3b87115-43423877
  Open-access
      Cheers, Doug

Kroon, F.J., Thorburn, Schaffelke and Whitten.  2016.  Towards protecting
the Great Barrier Reef from land-based pollution.  Global Change Biology
22: 1985-2002.

On Mon, Sep 2, 2019 at 5:04 AM <tomascik at novuscom.net> wrote:

> The media tries to sensationalize just about everything these days, so it
> is good to see that some media outlets are trying to keep it realistic.
> But, even the CBC.ca article is based on too few facts. It is frustrating
> to keep reading stuff like
>
> "The two main problems facing the Great Barrier Reef — which are
> elevated temperatures and lower pH…….,",
>
> when we know that the reasons for the decline in the health of the GBR
> over the decades are much more complex.
>
> In their 2017 Scientific Consensus Statement Waterhouse et al (2017)
> stated the overarching consensus is that:
>
> "Key Great Barrier Reef ecosystems continue to be in poor condition. This
> is largely due to the collective impact of land run-off associated with
> past and ongoing catchment development, coastal development activities,
> extreme weather events and climate change impacts such as the 2016 and
> 2017 coral bleaching events."
>
>
> https://www.researchgate.net/publication/319735304_2017_Scientific_Consensus_Statement_A_synthesis_of_the_science_of_land-based_water_quality_impacts_on_the_Great_Barrier_Reef_Chapter_5_Overview_of_key_findings_management_implications_and_knowledge_ga
>
> This report (Chapter 5 of the 2017 Scientific Consensus Statement)
> reflects what has been known as far back as 1990 through Peter Bell’s
> work
>
> (https://www.sciencedirect.com/science/article/abs/pii/004313549290228V)
>
> on the eutrophication of the GBR as a result of land-based development. A
> 2016 article in “The Conversation” stated the following:
>
> “Poor water quality – along with climate change, fishing, coastal
> development – is one of the major threats to the reef. Due to the
> cumulative impacts of these threats, the condition of the Great Barrier
> Reef has deteriorated over past decades.”
>
>
> http://theconversation.com/great-barrier-reef-pollution-controls-are-not-enough-heres-what-we-can-do-52861
>
> If significant progress is going to be made in addressing the decline of
> the GBR then we need to approach the problem in a holistic way, and not on
> a threat-by-threat basis. Yes we must keep addressing the climate change,
> but if we forget the more proximate causes for the GBR decline our climate
> change solutions will probably not matter much. I would like to point out
> that the Scientific Consensus Statement report was published in 2017, and
> yet 2 years later I have not found a single reference to this report in
> coral reef papers published in scientific journals on this topic. WHY?
>
> Tomas
>
>
> > No, this island of pumice will not help save the Great Barrier Reef
> >
> >
> https://www.cbc.ca/news/technology/great-barrier-reef-pumice-raft-1.5261123
> >
> > (Among other things, the raft would have to be near a coral reef just at
> > the right time for spawning to occur for it to get many coral larvae to
> > attach to the pumice.  Which is very unlikely.  There is documentation
> > that
> > corals can attach to the larger pieces of pumice and be carried over long
> > distances.  If you look along the stranding line on beaches in Australia
> > you can find such pumice even when we don't know of any such rafts.  When
> > I
> > did it, all I could find were small pieces of pumice a few cm diameter or
> > less, and I never found a single one with a coral attached.  Granted I
> > didn't spend a lot of time looking, and I searched maybe 100 m at most,
> of
> > beaches which stretch for perhaps 3500 km.  Plus, in order to seed any
> > larvae on the reef, a piece of pumice would have to be large enough and
> > have floated long enough for the coral to have grown to reproductive size
> > without having sunk the pumice from its weight, and would have to be
> close
> > enough to a reef during spawning season to have larvae from the colony on
> > the pumice settle on the reef.  (or to happen to reach the exact size
> > needed to sink the pumice right when it was over the reef, instead of
> > somewhere else in the vast ocean).  Far more likely to be floating way
> out
> > at sea or hard up on the stranding line on the beach dead from
> > desiccation.  It was a nice idea, but the number of new corals brought to
> > the reef by pumice is likely to be infinitesimal compared to the size of
> > the reef.  Enough, however, to at some point in a long period of time,
> > possibly carry a coral to a new location outside its former range.  But
> > that's very different from reseeding a huge population on a vast reef
> > system.)
> >
> > Jokiel, P.L.  1989.  Rafting of reef organisms and other organisms at
> > Kwajelein Atoll.  Marine Biology 101: 483-493.
> >
> > Jokiel PL  (1990)  Long-distance dispersal by rafting: re-emergence of an
> > old hypothesis.  Endeavour 14: 66-73.
> >
> > Jokiel, P.L. and Martinelli, F.J.  1992.  The vortex model of coral reef
> > biogeography.  Journal of Biogeography 449-458.
> >
> > Cheers, Doug
> > --
> > Douglas Fenner
> > Ocean Associates, Inc. Contractor
> > NOAA Fisheries Service
> > Pacific Islands Regional Office
> > Honolulu
> > and:
> > Consultant
> > PO Box 7390
> > Pago Pago, American Samoa 96799  USA
> >
> > A call to climate action  (Science editorial)
> >
> https://science.sciencemag.org/content/364/6443/807?utm_campaign=toc_sci-mag_2019-05-30&et_rid=17045989&et_cid=2840296
> >
> > New book "The Uninhabitable Earth"  First sentence: "It is much, much
> > worse
> > than you think."
> > Read first (short) chapter open access:
> >
> https://www.pbs.org/newshour/arts/read-a-chapter-from-the-uninhabitable-earth-a-dire-warning-on-climate-change
> >
> > Want a Green New Deal?  Here's a better one.
> >
> https://www.washingtonpost.com/opinions/want-a-green-new-deal-heres-a-better-one/2019/02/24/2d7e491c-36d2-11e9-af5b-b51b7ff322e9_story.html?utm_term=.a3fc8337cbf8
> > _______________________________________________
> > Coral-List mailing list
> > Coral-List at coral.aoml.noaa.gov
> > https://coral.aoml.noaa.gov/mailman/listinfo/coral-list
> >
>
>
>

-- 
Douglas Fenner
Ocean Associates, Inc. Contractor
NOAA Fisheries Service
Pacific Islands Regional Office
Honolulu
and:
Consultant
PO Box 7390
Pago Pago, American Samoa 96799  USA

A call to climate action  (Science editorial)
https://science.sciencemag.org/content/364/6443/807?utm_campaign=toc_sci-mag_2019-05-30&et_rid=17045989&et_cid=2840296

New book "The Uninhabitable Earth"  First sentence: "It is much, much worse
than you think."
Read first (short) chapter open access:
https://www.pbs.org/newshour/arts/read-a-chapter-from-the-uninhabitable-earth-a-dire-warning-on-climate-change

Want a Green New Deal?  Here's a better one.
https://www.washingtonpost.com/opinions/want-a-green-new-deal-heres-a-better-one/2019/02/24/2d7e491c-36d2-11e9-af5b-b51b7ff322e9_story.html?utm_term=.a3fc8337cbf8