[Coral-List] Artificial Reefs?

John McManus jmcmanus at rsmas.miami.edu
Sun Oct 27 15:02:39 EDT 2013

Interesting points.

An artificial underwater structure (AUS) which becomes overgrown with coral
is still an artificial underwater structure. Almost anything one puts in the
ocean long enough will become overgrown with marine life, as I discussed in
my earlier post. These are purpose-built structures. If the purpose was to
create a barrier to guide water flow, it is an artificial underwater
barrier. If the purpose was to alter local ecology through habitat
provision, then it is an artificial underwater habitat (FADs and artificial
underwater substrates are subtypes of these). If the purpose was to do both,
or to add in some other objective, then it is a multipurpose underwater
structure. If some people are still not sure what to call a structure placed
underwater artificially, then the broader term artificial underwater
structure is fine.

Concerning the public using the 'artificial reef' term, misleading public
terminology has often been widely corrected. For example, decades ago, we
learned of creatures called 'killer whales'.   However, a large group of
scientists and conservationists decided that the term was misleading, and
promoted the alternate term 'orca'. Nowadays, most people who know much
about orcas call them orcas. If anyone calls them 'killer whales', it is
taken as a sign of, at best, being out-of-date, and at worst, ignorance.

Concerning the term 'reef', the Oxford English Dictionary, 2nd edition 1989,
defines 'coral reef' much differently than it does 'reef'. Fortunately, it
has no definition at all for 'artificial reef' -- making it easier to
disregard this recent, artificial, and highly misleading term.

The term 'reef' is a respelling of 'rif' or 'riff', short for 'riffle', and
its use extends back several centuries. The definition of relevance here is
given as:  "A narrow ridge or chain of rocks, shingle, or sand, lying at or
near the surface of the water." That is very specific, and does not include
most of the structures of concern here. It does, of course, cover the rock
structure associated with the Exxon Valdize oil spill. 

A 'coral reef' here is defined in the  OED as; "A reef or marine bank of
rock formed by the growth and deposit of coral; 'a connected mass of coral
structures, whether trending away in long partially-submerged ledges,
encircling islands like breakwater-barriers, or rising as low ring-shaped
islets over the water' (Page)". The term 'bank' gives this definition much
broader applicability, and can justify the use of 'coral reef' for
mesophotic and deepwater natural structures formed via deposition associated
with coral. 

Regarding planting corals, one usually finds artificial underwater
structures involved, which are part of the habitat being developed, and
therefore rightfully called 'artificial underwater habitats', or more
specifically, 'artificial underwater substrates', in recognition of the NMFS
term. Whether or not these artificial structures are used, one is merely
creating coral patches, not coral reefs, though some people do try to add to
the coral patches growing on coral reefs. A coral patch, does not have to be
growing on a true coral reef. In early papers by Tom Goreau Senior, a group
of corals not growing on a true coral reef would be a 'coral community',
though nowadays this term is also used for coral patches growing on true
coral reefs. For many of us, the only stigma often associated with coral
planting is when it is done instead of taking care of the reason the corals
died in the first place. If the problem was one-off, or has been remedied,
and coral planting is rationally economically feasible, then planting coral
is fine. In some cases, it may even make sense to use coral planting as a
public awareness mechanism, as long as the program encourages people to
protect coastlines rather than replace large-scale protection with
small-scale planting. 

We should include Pleistocene and sometimes previous substrates, which were
originally built up by coralline ecosystems and then modified at low stands
of sea level, as coral reef structures -- even without much more buildup in
the last few thousand years. They are, after all, critical in understanding
the shapes of most atolls. What we see now is often a complex combination of
build-up and erosion periods. 

We do indeed have in common use both informal and formal uses of the term
'coral reef'. The informal one is pretty much what I described above as a
'coral patch'. 

So, let's follow and build on the lead of NMFS and others, and stop using
the 'AR' term.



John W. McManus, PhD
Director, National Center for Coral Reef Research (NCORE)
Professor, Marine Biology and Fisheries
Coral Reef Ecology and Management Lab (CREM Lab)
Rosenstiel School of Marine and Atmospheric Science (RSMAS)
University of Miami, 4600 Rickenbacker Causeway, Miami, 33149
jmcmanus at rsmas.miami.edu      http://ncore.rsmas.miami.edu/
Phone: 305-421-4814   

"Far better an approximate answer to the right question, which is often
   than an exact answer to the wrong question, which can always be made
     --John Tukey, Statistician, National Medal of Science and IEEE Medal of


-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov
[mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Eugene Shinn
Sent: Friday, October 25, 2013 12:42 PM
To: coral-list at coral.aoml.noaa.gov
Subject: [Coral-List] Artificial Reefs?

John, It is interesting to see that the old arguments and views regarding
artificial reefs and their functions is still with us after all these years.
     Your other posting may be opening a can of worms by suggesting new
terms for these structures/things.  What will we call an "artificial
underwater structure (AUS)" that becomes overgrown with coral?  How much
coral growth is required for it to become a coral reef? Maybe that makes it
a "multipurpose underwater structure (MUS)"  or is it a "artificial
underwater habitat (AUH)? It gets confusing and I agree with Le Berre the
public will still call them reefs.
Seems we have our hands full just deciding what is a coral reef and what is
not a coral reef. That has been argued every since I can remember. 
Here is an example: Most of the 150 miles of outer so-called coral reef
tract off the Florida Keys is so thin (in many areas less than 1 m thick and
others it is just exposed Pleistocene limestone with occasional coral heads,
sponges, and gorgonians)  it qualifies as a "hard ground" 
rather than a true reef built up by corals. What are we going to do about
things like Bligh Reef that is simply a submerged mountain top with no coral
growth. That's the "thing" that the Exxon Valdize struck up off Alaska.
Similar "things" called reefs are scattered all over the map and many of
them are simply sand bars.
     As for transplanted corals that is another matter. It occurs to me that
thinking about artificial reefs as corals transplanted from one place to
another is very much like farming on land. Farms are composed of edible
plants that have been transplanted from some natural place to an artificial
plowed-up man-made place. Whats the difference other than one is underwater
and the other is not? We glorify farmers but look down on coral
     As for Le Berre's idea to prevent people from fishing  around rigs just
isn't going to work in places were there are avid fishermen. The world is so
divided on so many issues this would just be another issue. 
There really are just two kinds of people Or as Jimmy Buffett says in his
song Fruitcakes, "humans are screwed up individuals"  Gene


No Rocks, No Water, No Ecosystem (EAS)
------------------------------------ -----------------------------------
E. A. Shinn, Courtesy Professor
University of South Florida
College of Marine Science Room 221A
140 Seventh Avenue South
St. Petersburg, FL 33701
<eugeneshinn at mail.usf.edu>
Tel 727 553-1158
---------------------------------- -----------------------------------

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