number of the colonies showed no growth on the concrete
plugs at all.
One of the cored colonies had no plug and acted as
a control. This colony not only had apparent damage
which could be attributed to the coring activity, but also
showed very little of the horizontal growth evident, where
plugs were used.
Cores taken from massive long lived corals can provide
valuable paleoclimatic information and coral growth histories. The value of these cores must be weighed against
the potential risk to the colonies from which the cores
are extracted. Sealing the core holes with tapered concrete
plugs that have been conditioned by long pre-immersion
in sea water reduces the likelihood of long-term damage
to cored colonies and in many cases assists the colony to
overgrow the damaged area in a relatively short time.
1
The term “coral bommie” is used in Australia to
describe large outcrops of coral often visible from the surface, usually separated from the main reef. In this article, it
refers specifically to individual, living colonies of the
Porites genus as seen in Figure 1.
Cross-references
Reef Drilling
Core Plugs, Figure 4 The upper portion of this image shows part
of a colony cored and plugged a month before the photo was
taken. The lower portion of the image shows the same colony
36 months later. The healthy coral has continued growing
normally and covered both plugs completely.
296
CORE PLUGS