[Coral-List] article on coral disease associated with plastic waste

frahome at yahoo.com frahome at yahoo.com
Mon Apr 13 21:02:41 UTC 2020


 As the article talks mainly about "entanglement" it brings to mind only macroplastics to be seen by naked eye, but it seems that a bigger role might be played by microplastics. Here an interesting documentary on the subject that will be available for free streaming only until tomorrow (in English with Italian subtitles):https://cinemambiente.it/movie/pceani-il-mistero-della-plastica-scomparsa/I found particularly interesting the Woods Hole research featured from min 37 (reference 10 of the Science article).Probably this issue could be just an additional burden for coral reefs as other anthropogenic impacts, on top of the main threat coming from global warming.Francesca

    On Friday, April 10, 2020, 02:46:51 PM GMT+2, Douglas Fenner via Coral-List <coral-list at coral.aoml.noaa.gov> wrote:  
 
 Concerning the last article I referred to, about plastic waste.

The Asia-Pacific area certainly does release a lot of plastic into the
ocean.  At the density of plastic this article reported on reefs (average
of one piece per 3 sq meters) since most of them cause disease on the coral
they touch, I'm amazed that there are any corals left alive to survey.

I see the article points out that there was plastic only on 1/3 of their
survey sites.  They report that corals which had plastic touching them had
much higher rates of coral disease than those that did not.  Seems pretty
airtight, plastic causes or allows coral disease somehow, one way or
another.  But could it be that other objects rubbing against corals can
break through the tissue and let microbes into the tissue, including
disease?  Seems to me there was article that demonstrated that with
algae.  Nugues
MM, Smith GW, Van Hooidonk RJ, Seabra MI, Bak RPM (2004) Algal contact as a
trigger for coral disease. Ecology Letters 7: 919–923.  So macroalgae
rubbing on coral can break the surface of the coral tissues and let disease
microbes in.  How about other kinds of objects on reefs, like other kinds
of trash??  Metal, wood, cloth, building materials, etc??  If they are
moving and hit the coral tissues, couldn't they open it up for invasion?
If microbes inhabit the surfaces of other trash, couldn't they get in
through the broken coral tissue surface?  So is the effect due to plastic,
or any loose, moving object contacting coral that could break its
surface??  Is it a general trash problem not just a plastic problem??

    Second, one could easily conclude that the world's reefs are plagued
with plastic causing coral disease all over the place.  That doesn't fit
with my experience of about 35 or 40 years on reefs, including in a variety
of sites around the Pacific in recent years.  Doesn't plastic float?
Granted, plastic bags have such a huge surface to volume ratio they can't
float upward to the surface.  Also, if plastic gets fouled by enough weight
it can sink.  I saw a beach in Belize back in 1994 that was just plastered
with plastic.  It faced eastward and winds blew plastic onto the beach so
fast that if you cleaned it off (as we did), in a few days it was all
back.  Yet in 6 days of diving a week plus snorkeling on the 7th, I don't
remember seeing a single bit of plastic on living coral in the water.
Probably found a few and put them in my pocket, but if there had been a lot
I would remember.  I have had a similar experience in American Samoa.  I
know a beach which is covered in plastic, wind blows it there as it floats
on the surface of the ocean.  We've had big teams out there to clean it all
up, tons and tons of it, truck loads.  In a few weeks it's all back.  Go
diving or snorkeling and it is quite hard to find a single bit of plastic
on coral in American Samoa.  I have seen it, several weeks ago I found 2
plastic bags on staghorn, and removed it.  But I see precious little.  I
worked 2 years in the Philippines, ending about 22 years ago.  Some plastic
on beaches, and I remember a place in one village where plastic was like
snow on the ground (and other places with much less).  We dove 6 days a
week, and I remember only picking up a few pieces of plastic off the reefs
and putting them in my BC pocket.  Once after diving on a reef with little
or no plastic, a whale shark approached our boat and I got in the water and
swam with it.  The water was full of plastic like I've never seen before or
since.  Never saw that in the water any other place in the Philippines, or
anywhere else in the Coral Triangle, or anywhere else.  Mind you, I've seen
photos of trash, much of it plastic, floating in an almost solid raft near
shore.  Also, plastic has increased a lot in the 20 or so years since I've
done any work in the Coral Triangle.
    I did not see anywhere where the article says that the density of
plastic they recorded is typical of the whole world's reefs, they didn't
claim that.  They did say, I believe, that the Asia-Pacific region has some
of the highest rates of release of plastic into the ocean.  From which one
might deduce that other places are not that bad.
      Is plastic a problem for corals in some areas??  I don't see how one
could say "no."  Is it a huge problem for corals everywhere?  I wonder if
we can be sure the answer is "yes."  Are there other kinds of
human-produced trash on reefs that can cause diseases as well?
      Surely this article is a good wake up call for the world community
concerned with coral reefs.
      We all hate plastic (in part because it is not biodegradable), but
should we exercise some caution in extrapolating these results to
everywhere?
Cheers,  Doug

On Tue, Apr 7, 2020 at 11:03 AM Douglas Fenner <douglasfennertassi at gmail.com>
wrote:

> Great Barrier Reef suffers its most widespread mass bleaching event on
> record
>
>
> https://www.washingtonpost.com/weather/2020/04/06/great-barrier-reef-coral-bleaching/?fbclid=IwAR0GCpjAaEuQOv-NbYDKlED1q4x53qW77_lDDicaUphIVTbUFd3DiMoNCIE
>
> Rescuing the Great Barrier Reef: how much can be saved, and how can we do
> it?
>
>
> https://www.theguardian.com/environment/2020/apr/05/rescuing-the-great-barrier-reef-how-much-can-be-saved-and-how-can-we-do-it?fbclid=IwAR0aEy1UZTIslcC1sdJp64JS0vdN9r-6MDwLuewFaAjXXntp2tlcLO-ZUc0
>
>
> Uncoupling temperature-dependent mortality from lipid depletion for
> scleractinian coral larvae.  Coral Reefs 2017, 36: 97-
>
> https://link.springer.com/article/10.1007/s00338-016-1501-5
>
> Algal symbionts increase oxidative damage and death in coral larvae at
> high temperatures.  Marine Ecology Progress Series 2009, 378: 105-
>
>  https://www.int-res.com/articles/meps_oa/m378p105.pdf
>
> open-access
>
> Plastic waste associated with disease on coral reefs
> Science 2018, 359: 460-
>
> https://science.sciencemag.org/content/359/6374/460
>
> open-access
>
> Cheers, Doug
>
>
> --
> Douglas Fenner
> Lynker Technologies, LLC, Contractor
> NOAA Fisheries Service
> Pacific Islands Regional Office
> Honolulu
> and:
> Consultant
> PO Box 7390
> Pago Pago, American Samoa 96799  USA
>
> "Already, more people die  <http://www.nws.noaa.gov/om/hazstats.shtml>from
> heat-related causes in the U.S. than from all other extreme weather events
> ."
>
> https://www.npr.org/2018/07/09/624643780/phoenix-tries-to-reverse-its-silent-storm-of-heat-deaths
>
>
> Even 50-year old climate models correctly predicted global warmng
>
> https://www.sciencemag.org/news/2019/12/even-50-year-old-climate-models-correctly-predicted-global-warming?utm_campaign=news_weekly_2019-12-06&et_rid=17045989&et_cid=3113276
>
> "Global warming is manifestly the foremost current threat to coral reefs,
> and must be addressed by the global community if reefs as we know them will
> have any chance to persist."  Williams et al, 2019, Frontiers in Marine
> Science
>
>

-- 
Douglas Fenner
Lynker Technologies, LLC, Contractor
NOAA Fisheries Service
Pacific Islands Regional Office
Honolulu
and:
Consultant
PO Box 7390
Pago Pago, American Samoa 96799  USA

"Already, more people die  <http://www.nws.noaa.gov/om/hazstats.shtml>from
heat-related causes in the U.S. than from all other extreme weather events."


https://www.npr.org/2018/07/09/624643780/phoenix-tries-to-reverse-its-silent-storm-of-heat-deaths


Even 50-year old climate models correctly predicted global warmng
https://www.sciencemag.org/news/2019/12/even-50-year-old-climate-models-correctly-predicted-global-warming?utm_campaign=news_weekly_2019-12-06&et_rid=17045989&et_cid=3113276

"Global warming is manifestly the foremost current threat to coral reefs,
and must be addressed by the global community if reefs as we know them will
have any chance to persist."  Williams et al, 2019, Frontiers in Marine
Science



-- 
Douglas Fenner
Lynker Technologies, LLC, Contractor
NOAA Fisheries Service
Pacific Islands Regional Office
Honolulu
and:
Consultant
PO Box 7390
Pago Pago, American Samoa 96799  USA

"Already, more people die  <http://www.nws.noaa.gov/om/hazstats.shtml>from
heat-related causes in the U.S. than from all other extreme weather events."


https://www.npr.org/2018/07/09/624643780/phoenix-tries-to-reverse-its-silent-storm-of-heat-deaths


Even 50-year old climate models correctly predicted global warmng
https://www.sciencemag.org/news/2019/12/even-50-year-old-climate-models-correctly-predicted-global-warming?utm_campaign=news_weekly_2019-12-06&et_rid=17045989&et_cid=3113276

"Global warming is manifestly the foremost current threat to coral reefs,
and must be addressed by the global community if reefs as we know them will
have any chance to persist."  Williams et al, 2019, Frontiers in Marine
Science
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