Coral
reefs develop best where conditions for growth of corals and red
calcareous algae are most favorable. If a coral reef is
defined as a wave-resistant feature built mainly of reef-building
corals and red calcareous algae, then the rigid reef framework
of interlocked skeletons that absorbs much of the wave energy
can be considered the basic or fundamental part of the reef. If
the reef framework is to remain intact or grow in size, the rate
at which erosion removes material must be offset by an equal or
greater rate of accretion or growth. If the rate of accretion
is greater than erosion the reef framework enlarges, either by
upward growth to near sea level or peripheral progradation, or
both. Think about what would happen if reef framework growth
was less than that of erosion. Such conditions could be
caused by anything that would decrease the favorable growing conditions
for reef-building corals and red calcareous algae at the site
of reef framework development to the level where erosion would
be greater than growth. A natural catastrophe such as physical
damage caused by a typhoon or storm, increased rates of predation
on reef-building organisms, changes in relative sea level, or
man-induced pollution and destruction might reverse a positive
balance of growth. Under such conditions the reef framework
would gradually be removed by erosion which would continue at
about the same rate as before. This would expose the depositional
areas of the reef system to wave exposure. The loose or
poorly cemented sediments of these environments would quickly
erode away and with time the reef would disappear and expose the
shoreline to wave erosion.
For coral
reefs to completely erode away, would, of course, take a long
period of time, and evidence indicates that the reefs of Guam
have endured the natural catastrophes mentioned above for millions
of years, but they have only been exposed to the activities of
man for a relatively short time. Modern man's ability to
alter, destroy, or irreversibly change the natural environment
around him is in evidence across the land and sea. In order
for Guam's coral reefs to continue their function and role as
a valuable natural resource, they must be conserved or used wisely
and managed properly. The wise use of our coral reefs requires
the attention of all the people, not just government agencies
or the business and industrial communities. Proper management
requires both an understanding of how the coral reef ecosystem
functions and an informed citizenry. A good starting point
for coral reef management is to prevent or mitigate uses and practices
that unnecessarily destroy or reduce their productivity and value
as a natural resource. Soil conservation practices and a
reduction in wildland burning would reduce the destructive effects
of sediment carried to reefs by rivers and streams. Programs
that would reduce harmful pollutants from reaching the reef system
range from good agricultural practices in the use of fertilizers,
insecticides, and herbicides to the proper disposal of solid wastes,
thermal effluent, and sewage discharges in the offshore waters.
Damage to reefs through the use of dynamite or chlorine
to kill fish and other reef organisms may seem insignificant to
some, but the indiscriminant loss and destruction of reef habitat
and other organisms makes the use of such methods one of the most
selfish and irresponsible acts by an individual. The use
of dynamite and chlorine to kill fish is now a felony on Guam.
Specific laws pertaining to Guam's corals include the following:
1) no coral may be taken or destroyed shoreward of the 10 fathom
(60 ft) contour surrounding Guam, 2) the taking of coral for any
purpose (commercial or otherwise) requires a permit from the Director
of Agriculture, 3) the following areas are closed to the taking
of coral: Cocos Lagoon, Apra Harbor, Agana Boat Basin, Luminao
Barrier Reef, and from Facpi Point north to the Nimitz Beach Channel,
and 4) it is unlawful to destroy coral for flushing fish when
net fishing.
HOW TO USE THIS HANDBOOK
The principal
use of this handbook will most likely be to determine species
names for reef corals. A species is the basic unit in the
taxonomist's classification scheme which consists of all the members
of a single kind of coral animal. Species are named by taxonomists
according to a set of rules called the International Code of Zoological
Nomenclature. In theory a coral species consists of all
the members of an interbreeding