What's a reef??

John Ware jware at erols.com
Wed Jan 16 10:48:34 EST 2002

Greetings to List,

As one who tried to find a consensus definition from the list 2 years
ago (without success), let me add my vote to Bob Buddemeier's statement
that definitions must be agreed upon before a meaningful discussion can
take place.

In particular, I do not necessarily see that attempting to define a
"coral reef" is an empty philosophical exercise.  Suppose the government
of country X were to decide to spend some millions of dollars (or
whatever) for protection of and research on coral reefs.  How does the
person or persons involved in administering that money decided whether a
proposed research project applies to the subject of the funding?

Despite the apparent beauty and simplicity of some proposed definitions,
I don't believe the definitions attain their goal.  For example, the
definition taken from the World Atlas of Coral Reefs and proposed
recently by Mark Spalding is:

"a physical structure which has been built up, and continues to grow
over decadal time-scales, as a result of the accumulation of calcium
carbonate laid down by hermatypic corals and other organisms."

This definition occurs on pg 16 of the text.  Unfortunately, the word
"hermatypic" is defined on pg 15 by stating that there is a subset of
corals that are a- communal and b- lay down a stony skeleton.  This is
followed by the statement that these corals are called hermatypic or
reef building.  In other words, a coral reef is a reef built by
reef-building corals!

Mike Risk proposes the very simple definition taken from a geological
context.  A reef is:

"a biologically-constructed, wave-resistant framework."

Clearly, to a sailor, the thing he runs aground on he calls a 'reef',
whether it was biologically constructed or not.  But there are even more
fundamental problems with this definition.  Specifically, what do the
words 'wave resistant' mean?  What size waves?  What frequency? How do
we address 'biologically-constructed' things that are not ever wave
affected so that their ability to resist waves cannot be easily

Even the word 'framework' is problematical.  The image I have of a
framework, which is shared by my desk dictionary, is a 'skeletal
structure like the framework of a building'.  Now clearly a coral reef
is skeletal.  But in this context, the word 'skeletal' refers to what we
see when a house is framed by 2 x 4s before the siding is put on.  In
other words, 'framework' does not apply to a solid structure.  Thus,
using Mike's definition, all massive structures are excluded.  Not
necessarily wrong, just different from my image.

When we hear the word "reef", we each form a mental picture, or set of
pictures, that depends upon our backgrounds and the context.  For
example, on this list, the word 'reef' almost always is interpreted to
mean a 'reef formed by zooxanthellate corals and associated organisms in
tropical waters' = a tropical, coral reef.  (I am not proposing that as
a definition, just a thought picture.)

The founders of an organization to which many of us belong, the
International Society for Reef Studies, clearly had something like this
in mind.  The Constitution states that the ISRS has the objective of
studying ** coral reefs **, so the word 'reef' in the organization
title doesn't mean the same thing to everyone.

Finally, back to Bob's point: As an engineer, one of the first rules I
learned about discussions is: "Make sure everyone knows what the
discussion is about."  Good rule, solves a lot of problems.


     *                                                           *
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