[Coral-List] Coral Reef?

Douglas Fenner douglasfennertassi at gmail.com
Mon Nov 9 09:49:38 UTC 2020


Indeed, Rogers does say that these deep cold water constructions have
diversity similar to shallow warm tropical coral reefs.  But I think the
claim that deep water "reefs" have diversity similar to shallow water coral
reefs bears a bit more examination.  As the Rogers article points out, deep
water bioherms have almost no hard coral diversity, one species compared to
about 500 in places like the Philippines or Indonesia.  There are zero
algae species on deep water bioherms, no light.  The article also says that
*Lophelia* reefs have 23 species of fish, that compares with 3000 in the
Coral Triangle on shallow warm water coral reefs.  It also says that
Mollusc diversity is low.  It compares Echinoderm diversity to the
Caribbean, but the Caribbean is basically depauperate compared to most of
the Indo-Pacfic.  The Caribbean has about 3 crinoids compared to about 100
in Indonesia.  Rogers says the total number of species found on
*Lophelia* reefs
so far is 899.  That's slightly more than the number of coral species alone
found on shallow tropical coral reefs.  The Gulf of Mexico report says over
1300 species on *Lophelia*.  8783 species have been reported from the reefs
of New Caledonia alone, see the reference below.  And we know that is a
minute fraction of the total species there, and it isn't even in the area
of the highest diversity, the coral triangle.  10 times the documented
diversity on *Lophelia* reefs, at a bare minimum.
       I stand by my statement that deep water bioherms are not as diverse
as shallow water tropical coral reefs.
       However, not all coral reefs have the high diversity of Coral
Triangle coral reefs, there is a wide range of diversity on coral reefs.
Hawaii and the Caribbean both have much lower diversity than the Coral
Triangle, with only about 65 species of coral and 650 species of fish, or
65 times and 28 times the diversity on *Lophelia* deep cold water bioherms
in the same groups.  Hawaii has about 3000 total species.  Then there are
Brazil and the Eastern Pacific with even lower diversity.  The Eastern
Pacific has the lowest diversity of any reef area I can think of.  If
memory serves, individual reefs there have up to about 10 species of coral,
some surely less.  They have about 200 species of fish, if I remember.  And
of course they have algae which the deep reefs don't have.  So in these
groups, even the lowest diversity coral reefs exceed the diversity of the
deep cold water bioherms.
      Cheers,  Doug

Payri, C., Richer de Forges, B.  2009.  Compendium of marine species from
New Caledonia.  IRD.  391pp.

On Sat, Nov 7, 2020 at 10:28 AM Gregory Boland <g_boland at hotmail.com> wrote:

> All - I just responded to Alina Szmant privately who expressed the same
> view, that a coral reef can not be termed a coral reef unless it can be hit
> by a boat. This would remove tens of thousands of square miles of living
> "coral reef" from places like the Great Barrier Reef and reefs all over the
> world at depths below 20 m or so. This does not seem reasonable despite the
> dictionary's definition of "reef." Maybe not so simple. Do we want to
> define all coral reefs of the world below 20 m as bioherms? I'm not
> pressing for some deep-water *Lophelia *habitats to be officially called
> "coral reefs" but, seems like the use of a single criteria (or any other
> combination) for a definition should be applied to all situations.
>
> The final report on *Lophelia *habitats in the Gulf of Mexico goes into
> biodiversity in several respects.
> https://espis.boem.gov/final%20reports/5522.pdf
>
> One of the introductory statements in the above report used an older 1999
> reference, but said regarding deep-water coral habitats, "The diversity of
> the community on these reefs rivals the diversity of many tropical
> zooxanthellate coral reefs (Rogers 1999)." Granted the number of coral
> species as well as fish and mollusks is much lower than shallow coral
> reefs, but Rogers describes very similar diversity in a variety of other
> taxa. The total comparison picture would be quite complex. Rogers 1999:
> https://www.researchgate.net/profile/Alex_Rogers2/publication/264469316_The_Biology_of_Lophelia_pertusa_Linnaeus_1758_and_Other_Deep-Water_Reef-Forming_Corals_and_Impacts_from_Human_Activities/links/59f82e5ea6fdcc075ec7dab9/The-Biology-of-Lophelia-pertusa-Linnaeus-1758-and-Other-Deep-Water-Reef-Forming-Corals-and-Impacts-from-Human-Activities.pdf
>
> Sincerely,
>
> Greg
>
> ------------------------------
>
>


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