[Coral-List] Giant barrel sponges taking over Florida's reefs!

Dennis Hubbard dennis.hubbard at oberlin.edu
Tue Sep 8 15:28:03 EDT 2015

I agree with Mike which is why I discuss the question, "What is a reef?"
only with close friends.


On Tue, Sep 8, 2015 at 2:05 PM, Risk, Michael <riskmj at mcmaster.ca> wrote:

>    Hi Doug.
>    I have never had a real problem with the old "geological" definition of
> a
>    reef as a "biologically-constructed wave-resistant structure." This
> would
>    mean that, for example, there are no true deep-water coral reefs, nor
> are
>    there likely to be reefs constructed by modern sponges. Of course, we
> have
>    had  ancient  reefs  made  by  ancient  sponges  with  hard  skeletons
>    (stromatoporoids), as well as brachiopods and huge oysters, and the list
>    goes on.
>    Where  I  might  take  issue  with you is your broad usage of the term
>    "ecologist.† I consider that an ecologist is one who studies the
> ecosystem.
>    There are many universities today at which one can obtain a PhD in
> "ecology"
>    without ever having had a course in earth sciences or, indeed, physics
> or
>    chemistry. I knew the biology department at my old university was in
> trouble
>    when  they  advertised  for  an "ecologist† and the title of the first
>    candidate's job seminar was “The ecology of T4 phage in the hind gut
> of the
>    rat."
>    I think you were referring to people I would call "biologists." Fine
> people
>    all, to be sure, but a real ecologist has a grasp on more things than
> just
>    biology.
>    Your separation of processes into biological and geological on the
> basis of
>    time is perhaps not a bad one, but I would point out that dead reefs
> already
>    have been shown to lose topographical complexity. It is that mixture of
>    habitats  that  allows  reefs  to support those diverse and entrancing
>    communities that so fascinate us. It only takes a decade for substantive
>    change to occur.
>    Mike
>    On Sep 4, 2015, at 4:46 PM, Douglas Fenner <[1]
> douglasfennertassi at gmail.com>
>    wrote:
>      Vassil,
>         Good point.  The geological reef structure was built by primarily
> by
>      corals, or at least the corals are important as baffling to hold it
>      together.  Algae often are very important contributors and can
> contribute
>      more calcium than corals.  They are coral reefs in the same sense as a
>      similar structure lifted 20 feet out of the water 100,000 years ago
> is a
>      coral reef.  But an uplifted reef above the water does not have a
> living
>      coral reef ecosystem on the surface.  The same is true of reefs that
> are
>      now dominated by algae, whether the algae is macroalgae (by which I
> mean
>      frondose or fleshy algae) or turf (by which I mean filamentous algae)
> or
>      coralline algae or mixtures or soft corals or other things.
>          Sometimes people talk or write about how reefs may die in coming
>      decades.  The geological structures won't die, though they have many
>      living
>      things in holes in the structure, I would think.  I don't think the
>      geological structures are going to disappear in a few decades,
> either.  I
>      presume that reefs in Florida that are now sponge-dominated instead of
>      being coral-dominated are not accumulating more calcium deposits,
> likely
>      they are loosing more than gaining, bioerosion likely is greater than
>      calcification (unless there are algae calcifying faster than the
>      bioerosion).  But I'm not as worried about the geological structure
> as the
>      ecosystem, in the relatively short term (decades).
>           I have sympathy for Mike Risk's view of the need for something
>      besides just ecologists, studying reefs.  I tend to think that with
> the
>      vast expansion of knowledge, individuals have to specialize.  I read
>      somewhere that about 1800 papers on coral reefs are being published
> each
>      year now and the rate is increasing fast.  No one can keep up with
> all of
>      it, and time spent outside of your specialty means less time to gain
> the
>      knowledge to be a competitive expert in your specialty.  So trying to
> be a
>      generalist is pretty self-defeating.  The answer is to have teams of
>      people
>      with different specialties, because as Mike rightly points out, coral
>      reefs
>      are very complex structures with many different things that require
>      different specialists to study, and many reef aspects need people in
>      several different specialists to study.  We already need
> statisticians on
>      our teams.  I agree ecologists probably need to work with geologists
> in
>      their teams more often.  I think ecologists need to consult with
>      taxonomists about identifications of their favorite organisms more
> often,
>      and geneticists need taxonomists on their teams.
>           But I also think that the coral reef crisis is an ecological
> crisis,
>      not really a geological crisis.  Oh, it will be in a few thousand
> years if
>      we keep this up.  But we are loosing coral reef ecosystems even if we
>      aren't loosing geological structures yet.  Both provide benefits for
>      humans.  But the scientific community is pretty nimble at shifting
> towards
>      the exciting parts of science, and a lot of people see the coral reef
>      crisis as important and so makes for exciting science.  Easier to get
>      funding on things important to society, so some of us shift to work on
>      those things.  Not a bad thing.
>           But I think you're right, Vassil, to be accurate, in some places,
>      what was a coral reef ecosystem is now a sponge-algal ecosystem on
> top of
>      a
>      dead coral reef.  Or something like that, I'm not sure what the best
> name
>      is.  Likely people will continue to call them "coral reefs" because
> that
>      is
>      a catchy name that we are all familiar with.  There is one on the
> south
>      side of Molokai Island in Hawaii which had a wide reef flat, a reef
> made
>      of
>      calcium carbonate.  The geological structure of carbonate is still
> there,
>      but the reef flat is almost completely covered with mud that has
> eroded
>      off
>      of agricultural fields on land.  A few tiny corals poke up through the
>      mud.  I saw similar along the east side of Lanai Island in Hawaii a
> couple
>      decades ago.  What should we call that?  Certainly that reef flat
> does not
>      have a coral reef ecosystem.  Mud ecosystem on top of a dead coral
> reef is
>      more like it.
>         In truth, many of the ecosystems we call coral reef ecosystems are
> not
>      actually dominated by corals.  Corals are an important component, but
> not
>      dominant.  True even on many reefs with very little human influence.
> Of
>      course humans have caused massive losses of corals on many or most of
> the
>      world's reefs.  Of course that's bad.
>         By the way, I LIKE sponges!  Caribbean sponges are large,
> colorful, and
>      their biology is very different and interesting.  Where I'm at in the
>      Pacific, sponges are small, uncommon, and cryptic.  Nothing like the
>      glorious sponges of the Caribbean.  They are not completely
> incompatible
>      with corals.  Cozumel used to have good coral on top of the reefs, and
>      fabulous sponge communities on overhangs.  Spectacular.  Wonderful
> part of
>      the ecosystem.
>          Cheers,  Doug
>      On   Wed,   Sep   2,   2015   at   12:19   AM,   Vassil   Zlatarski
>      <[2]vzlatarski at gmail.com>
>      wrote:
>      Well, Joseph, in such case the usage of “coral reefs† should be
> precised,
>      for example, "coral-limestone reefs" or “dead-coral reefs† or
>      “not-living-coral reefs† or in other appropriate way.
>      Best,
>      Vassil
>      Vassil Zlatarski
>      D.Sc. (Biology), Ph.D. (Geology)
>      ---------- Forwarded message ----------
>      From: Pawlik, Joseph <[3]pawlikj at uncw.edu>
>      Date: Wed, Sep 2, 2015 at 5:31 AM
>      Subject: RE: [Coral-List] Giant barrel sponges taking over Florida's
>      reefs!
>      To: Vassil Zlatarski <[4]vzlatarski at gmail.com>
>      Agreed, Vassil,
>      But the reef was built by coral (it's limestone) -- they just aren't
>      building it anymore!
>      **************************************************************
>      Joseph R. Pawlik, Professor
>      Department of Biology and Marine Biology
>      UNCW Center for Marine Science
>      5600 Marvin K Moss Lane
>      Wilmington, NC  28409   USA
>      [5]pawlikj at uncw.edu; Office:(910)962-2377; Cell:(910)232-3579
>      Website: [6]http://people.uncw.edu/pawlikj/index.html<
>      [7]https://mail.uncw.edu/owa/UrlBlockedError.aspx>
>      PDFs: [8]http://people.uncw.edu/pawlikj/pubs2.html<
>      [9]https://mail.uncw.edu/owa/UrlBlockedError.aspx>
>      **************************************************************
>      ________________________________
>      From: Vassil Zlatarski [[10]vzlatarski at gmail.com]
>      Sent: Wednesday, September 02, 2015 4:25 AM
>      To: Coral-List Subscribers; Pawlik, Joseph
>      Subject: Re: [Coral-List] Giant barrel sponges taking over Florida's
>      reefs!
>      Dear Coral-Listers,
>      Prof. Pawlik offered interesting paper “Population dynamics of giant
>      barrel
>      sponges on Florida coral reefs† and video adding to the growing
> evidence
>      that reef-building corals are declining and sponges are becoming the
>      dominant inhabitants of modern Caribbean benthic communities.  For the
>      fortunate researchers of coral reefs 4-5 decades ago is strange the
> usage
>      of “coral reefs† for the documented now-existing situation.  Is
> it not in
>      reality a case of “sponge gardens†?
>      Cheers,
>      Vassil
>      Vassil N. Zlatarski
>      D.Sc. (Biology), Ph.D. (Geology)
>      On    Tue,    Sep   1,   2015   at   10:45   AM,   Pawlik,   Joseph
>      <[11]pawlikj at uncw.edu<mailto:
>      [12]pawlikj at uncw.edu>> wrote:
>      Greetings, Colleagues,
>      In a 12-year study just published in the Journal of Experimental
> Marine
>      Biology and Ecology, we report that populations of giant barrel
> sponges
>      have increased by 122% since 2000 on Conch Reef, off the coast of Key
>      Largo,  Florida. This adds to the growing evidence that sponges are
>      becoming
>      the dominant inhabitants of modern Caribbean reefs.  The article can
> be
>      downloaded for free:
>      [13]http://authors.elsevier.com/a/1RcjD51aUK0hE
>      Giant barrel sponges (Xestospongia muta) are found throughout the
>      Caribbean, and commonly grow to the size of an oil drum or larger.
> Called
>      the "redwoods of the reef," these sponges can live to be hundreds,
> even
>      thousands of years old, based on earlier growth studies conducted by
> the
>      same first author, Dr. Steven McMurray.
>      A video tour of the plots on Conch Reef can be seen here:
>      https://youtu.be/qdjhm7ojGJk
>      You can see how large these sponges get in this video from the
> Bahamas:
>      https://youtu.be/8WaWVuGE-LM
>      Not only are the numbers of giant barrel sponges increasing, so is
> their
>      volume, with a 39% increase since 2000. On average, each square meter
> of
>      Conch Reef now has about 2 liters of barrel sponge tissue on its
> surface,
>      more than any other organism on the reef.  And the giant barrel
> sponge is
>      only one of many species of sponges that populate Caribbean coral
> reefs.
>      Much of the increase in the numbers of giant barrel sponges was due to
>      recruitment - the successful establishment of baby sponges. On some
> plots,
>      the increase in the smallest-sized barrel sponges was over 600% for
> the
>      period 2000-2012. And while the survival of larger barrel sponges was
>      stable for the first half of this period, it increased during the
> second
>      half, perhaps because of the absence of hurricanes over that time
> period.
>      When hurricanes pass over reefs, large sponges can be damaged and
>      dislodged, often resulting in mortality.
>      Regards,
>      **************************************************************
>      Joseph R. Pawlik, Professor,
>      Dept. of Biology and Marine Biology
>      UNCW Center for Marine Science
>      5600 Marvin K Moss Lane
>      Wilmington, NC  28409
>      Office:(910)962-2377<tel:%28910%29962-2377>; Cell:(910)232-3579
>      <tel:%28910%29232-3579>
>      Website: http://people.uncw.edu/pawlikj/index.html
>      PDFs: http://people.uncw.edu/pawlikj/pubs2.html
>      Video Channel: https://www.youtube.com/user/skndiver011
>      **************************************************************
>      _______________________________________________
>      Coral-List mailing list
>      Coral-List at coral.aoml.noaa.gov<mailto:Coral-List at coral.aoml.noaa.gov>
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>      --
>      Douglas Fenner
>      Contractor with Ocean Associates, Inc.
>      PO Box 7390
>      Pago Pago, American Samoa 96799  USA
>      phone 1 684 622-7084
>      Join the International Society for Reef Studies.  Membership includes
> a
>      subscription to the journal Coral Reefs, there are discounts for pdf
>      subscriptions and developing countries.  [14]www.fit.edu/isrs/
>      "Belief in climate change is optional, participation is not."- Jim
> Beever.
>       "Everyone is entitled to their own opinion, but not to their own
> facts."-
>      Daniel Patrick Moynihan.
>      Energy policy: push renewables to spur carbon pricing.  (the world
>      subsidizes fossil fuels a half Trillion dollars a year!)
>      [15]
> http://www.nature.com/nature/journal/v525/n7567/full/nature14876.html?
>  WT.ec_id=NATURE-20150904&spMailingID=49465812&spUserID=MjA1NTA3MjA0OQS2&sp
>      JobID=760401953&spReportId=NzYwNDAxOTUzS0
>      Historically unprecedented global glacier decline in the early 21st
>      century...
> http://www.ingentaconnect.com/content/igsoc/jog/pre-prints/content-ings_jo
>      g_15j017
>      Hottest July on record keeps 2015 on track to crush 2014 for hottest
> year.
> http://thinkprogress.org/climate/2015/08/14/3691940/hottest-july-hottest-y
>      ear-record/
>      website:  http://independent.academia.edu/DouglasFenner
>      blog: http://ocean.si.edu/blog/reefs-american-samoa-story-hope
>      _______________________________________________
>      Coral-List mailing list
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>    Risk, Michael
>    [16]riskmj at mcmaster.ca
> References
>    1. mailto:douglasfennertassi at gmail.com
>    2. mailto:vzlatarski at gmail.com
>    3. mailto:pawlikj at uncw.edu
>    4. mailto:vzlatarski at gmail.com
>    5. mailto:pawlikj at uncw.edu
>    6. http://people.uncw.edu/pawlikj/index.html
>    7. https://mail.uncw.edu/owa/UrlBlockedError.aspx
>    8. http://people.uncw.edu/pawlikj/pubs2.html
>    9. https://mail.uncw.edu/owa/UrlBlockedError.aspx
>   10. mailto:vzlatarski at gmail.com
>   11. mailto:pawlikj at uncw.edu
>   12. mailto:pawlikj at uncw.edu
>   13. http://authors.elsevier.com/a/1RcjD51aUK0hE
>   14. http://www.fit.edu/isrs/
>   15.
> http://www.nature.com/nature/journal/v525/n7567/full/nature14876..html?WT..ec_id=NATURE-20150904&spMailingID=49465812&spUserID=MjA1NTA3MjA0OQS2&spJobID=760401953&spReportId=NzYwNDAxOTUzS0
>   16. mailto:riskmj at mcmaster.ca
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Dennis Hubbard
Chair, Dept of Geology-Oberlin College Oberlin OH 44074
(440) 775-8346

* "When you get on the wrong train.... every stop is the wrong stop"*
 Benjamin Stein: "*Ludes, A Ballad of the Drug and the Dream*"

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