[Coral-List] effect of sunscreen on corals
Douglas Fenner
douglasfennertassi at gmail.com
Tue Feb 5 23:09:17 UTC 2019
My post below is way too long, don't read if you don't want to spend
the time on the topic.
Readers will note that I often post links to a wide variety of
articles about different aspects of coral reefs. I do that primarily to
let people know that those articles exist. It doesn't mean I either
endorse them or don't like them, I just think it would be good for people
to be aware of them. I don't think I included a statement endorsing the
conclusions of this essay. Full disclosure: I'm not a toxicologist and I
know little about the subject. But what he wrote seemed to make sense.
I think the swipe at Terry Hughes might be just a bit more than
absolutely required. He led teams that documented heavy mortality on the
GBR due to mass coral bleaching from high temperatures, the world's largest
barrier reef and one of the world's largest coral reef systems. Mortality
was unprecedented. People in the Indian Ocean have documented up to 90%
coral mortality in many places due to the mass coral bleaching from El Nino
and global warming combined, particularly the 1998 El Nino and the last few
years; it's caused significant damage some other places as well. As far as
I know, the evidence is that global warming has killed more corals in any
one or two years than any other cause. There are, however, a long laundry
list of things that have been well documented to be killing corals around
the world, some global, some local, and several of which are major. One
published list can be found in Brainard, et al (2013, Table 1), which
doesn't even list some things we know that damage coral, like diver damage,
and possibly damage corals, like sunscreens. But for the reefs of the
whole world, sunscreens are NOT a major threat, which is a point I've made
before. On the other hand, local threats can be important in local areas,
and it is quite possible that sunscreens may be among those in some
locations, particularly enclosed bodies of water with little circulation
and high tourist use. Those two things, lack of a global threat from
sunscreens, and the possibility of local threats from sunscreens, are not
contradictory, both may be true. The former has mountains of evidence
supporting it, and the latter has a little now.
Speaking of "an attitude all too common among reef biologists,
namely: "the most important stress on coral reefs is the one on which I am
personally working on", I found a most interesting statement on the
Haereticus website. It says "Chemicals in sunscreen that come off while
swimming or travel through sewage systems when washed off in the shower are
“bigger than climate change,” in causing coral reef damage, according to
Craig Downs, the executive director of the Haereticus Environmental
Laboratory based in Clifford, Va., which has studied the effects of
sunscreen on coral reefs."
http://www.haereticus-lab.org/most-sunscreens-can-harm-coral-reefs-what-should-travelers-do/
Personally, I think that statement fits your point. Further, I think this
statement is ludicrous. There are various studies that have reported mass
coral bleaching and mortality on remote reefs with no people anywhere near
them, which coincide with high water temperatures, specifically "degree
heating weeks" which accurately predict when and where mass bleaching
happens, while proximity to dense populations of tourists using sunscreens
has not, to my knowledge, ever been shown to predict where mass coral
bleaching will and will not occur. A couple of good examples of places
with no tourists using sunscreen are the Chagos archipelago in the middle
of the Indian Ocean, and the northern Great Barrier Reef. Both of those
have had HUGE mass coral bleaching events when there has been hot water
events (90% of corals killed by high temperature mass bleaching in Chagos
twice now), and neither of them have tourists using sunscreens (a very
small number of scientists visiting these giant reef systems do use
sunscreen, but corals bleached even where they didn't go, as seen from
flying over the reef, which Hughes and others did- you can see the masses
of bleached corals from air even though no one has been in the water
there. There are essentially no people living on land near the northern
Great Barrier Reef, nor anyone living on all but one of the smaller atolls
in Chagos, many of the atolls there are far from any humans.). There are
thousands of scientific papers on corals and reefs in the literature, no
one has read them all, certainly not me, so if anyone knows of a
peer-reviewed paper that documents sunscreens predicting where corals
bleach and/or die and where not, please let me know. The documentation on
high water temperatures causing mass coral bleaching is overwhelming, and
as I said there are papers demonstrating that mass bleaching happens in
high water temperatures in reefs very far from tourists wearing
sunscreens. I repeat myself, that claim, which the quote attributes to
Downs, on the website of the organization he heads, is ludicrous.
As for bias, the Haereticus website sells certifications to people
and solicits donations. Downs is the director. So far I've heard that the
sunscreen industry has a source of bias, but I haven't heard anyone say
that Downs (who I neither know nor wish to impune in any way, I readily
accept what you say about him being a good scientist) has any source of
bias.
I think you have a good point, that every scientist wants to show
that their studies are important, and so if they work on a particular
threat to corals, they want everyone to know that it is important. Human
nature, not a conspiracy. I can't personally remember anyone ever saying
that their favorite threat is the ONLY threat to coral reefs. (the above
quote is the first I've seen saying sunscreen is a greater threat than high
water temperatures) Rather, I think there is a widespread agreement that
there are several or many threats to coral reefs. Everyone is entitled to
argue for their own views of which are the most important threats (based on
the evidence), but it seems clear that not all threats are created equal.
I don't think Terry Hughes and many of the rest of us who think mass coral
bleaching due to global warming and warming events is the greatest future
threat, think that on the basis of a whim, or because they work on them,
though experience with the effects of some major threats is likely to be
quite sobering. But I don't see any reason that just because one is
advocating that we do something about one threat, that that means there are
no other threats. I think, personally, that it is pretty obvious that
there are many threats to coral reefs. I've argued, however, that if a
doctor doesn't do triage, and their patient has a gunshot wound to the
chest and yet they only treat a scratch on the hand, they're going to loose
their patient. I argue that if the world doesn't act on global warming,
we're going to lose most of the world's corals. I see no evidence to
indicate that sunscreens threaten the world's corals. That doesn't mean
they are not a local threat to corals, they might be in some places (or
might not).
I think your argument is with Terry Hughes, but I also think it is
good to have open discussions on these things. Full disclosure: I have not
read Downs' paper yet, and even when I do, I am likely not to catch some of
the important things, because I have no training in toxicology.
I completely agree that people can work on some small things at the
same time we work on the big ones. Funding for coral reef research and
particularly management is pitifully inadequate world wide. Most of the
countries that have the most coral reefs cannot afford much (Australia
being the greatest exception; the US has a very small coral reef area).
The wealthiest countries are doing pitifully little to save reefs, and all
countries are way behind their pledges in the Paris agreement on climate
change, the US says it is withdrawing and reversing things that would
reduce emissions, and all the country pledges together are not nearly
enough to save reefs, let alone avoid disaster for humans such as heat
waves in the future that will kill multitudes. So I have my doubts about
the statement that it is not a zero sum game. In small ways it may not,
banning sunscreens will likely not detract any money from other work on
coral reefs, but statements like Downs' made on his website might convince
some or even many people that it is important more broadly than in small
local areas, something that climate deniers may love (but will have little
or any influence on how climate change battles work out, I'd guess). But
on the broader scale, it is very much the case that resources provided for
managing reefs particularly, are woefully inadequate. I tell people I
think that we were losing the battle to save reefs long before global
warming was recognized to have much of any effect on coral reefs. Now
we're losing far worse, and it will get far worse in the future, from all
or most all of the many threats, but particularly global warming.
I think statements like the one I labelled "ludicrous" are highly
misleading, and there is a public that would love to be able to do
something to help reefs, which is fertile ground for misleading statements
like this to cause a groundswell of public opinion which will lead to
wasted effort, money, and a distraction from the real threats to corals
worldwide.
Cheers, Doug
Brainard, et al. 2013. Incorporating climate and ocean change into
extinction risk assessments of 82 coral species. Conservation Biology 27:
1169-1178. See Table 1.
On Tue, Feb 5, 2019 at 7:50 AM Risk, Michael <riskmj at mcmaster.ca> wrote:
> Hi Doug.
>
> I find this screed by Terry to be deeply disappointing. Not only is it
> scientifically misleading, it epitomizes an attitude all too common among
> reef biologists, namely: "the most important stress on coral reefs is the
> one on which I am personally working." This attitude prompted my by-now
> ancient paper, Paradise Lost-not only has little changed since then, it
> seems things are even worse.
>
> Now, to the science.
>
> I urge you all to read one of the key papers, Downs et al 2016 Arch Env
> Contam Toxic 70: 265. It is simply not true that authors bathed their
> corals in unrealistically high concentrations of oxybenzone, nor is it true
> they lack real-world data. They report high concentrations of oxybenzone in
> VI waters, along with zero coral recruitment. This stuff is death to coral
> larvae, at unbelievably low concentrations.
>
> We need here to beware of some sort of false dichotomy. No one is saying,
> forego sunscreens. American readers will be surprised (or not) to learn
> that Europe banned the use of the known carcinogen oxybenzone in
> sunscreens, but American companies were allowed to get away with it. The
> research mentioned above has come under heavy criticism from the chemical
> industry in the US, quelle surprise. The answer is quite simple: avoid
> sunscreens that contain oxybenzone.
>
> Criticisms of the research seem based not so much on genuine scientific
> issues as some sort of zero-sum game attitude, that attention to sunscreen
> will detract from whatever flavour of the month turns your particular
> crank. This is a small thing we can all do for reefs whilst still working
> on the big things.
>
> Full disclosure: Craig Downs is a friend of mine, and in my opinion a
> brilliant scientist.
>
> Mike
> ________________________________________
> From: Coral-List [coral-list-bounces at coral.aoml.noaa.gov] on behalf of
> Douglas Fenner via Coral-List [coral-list at coral.aoml.noaa.gov]
> Sent: February 5, 2019 1:18 AM
> To: coral list
> Subject: [Coral-List] effect of sunscreen on corals
>
> There's insufficient evidence your sunscreen harms coral reefs.
>
> By Terry Hughes
>
>
> https://theconversation.com/theres-insufficient-evidence-your-sunscreen-harms-coral-reefs-109567
>
> Open-access.
>
> 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
>
> How to win public support for a global carbon tax
>
> https://www.nature.com/articles/d41586-019-00124-x
>
> Global warming will happen faster than we think.
>
> https://www.nature.com/articles/d41586-018-07586-5
>
> Nations falling short of emissions cuts set by Paris climate pact, analysis
> finds
>
>
> http://www.sciencemag.org/news/2018/11/nations-falling-short-emissions-cuts-set-paris-climate-pact-analysis-finds?utm_campaign=news_daily_2018-11-28&et_rid=17045989&et_cid=2515903
> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov
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>
--
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
How to win public support for a global carbon tax
https://www.nature.com/articles/d41586-019-00124-x
Global warming will happen faster than we think.
https://www.nature.com/articles/d41586-018-07586-5
Nations falling short of emissions cuts set by Paris climate pact, analysis
finds
http://www.sciencemag.org/news/2018/11/nations-falling-short-emissions-cuts-set-paris-climate-pact-analysis-finds?utm_campaign=news_daily_2018-11-28&et_rid=17045989&et_cid=2515903
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