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EXECUTIVE SUMMARY
The main objective for this pilot project was to conduct an experiment
and carry out surveys designed to provide a preliminary test of some of
the techniques most likely to be successful for small to moderate sized
coral reef restorations on the Great Barrier Reef. To do this, it was
necessary to review the scientific literature on previous attempts in
Australia and elsewhere so that techniques known to have little chance
of success could be eliminated from the study. The field research was
carried out at Lizard Island between March and July 1994.
Two methods of attachment of corals were thus examined: namely,
attachment to masonry nails using cable ties and cementation directly
on to bare reef substrate. These two methods were combined with an investigation
(within the same experiment) of methods of handling corals prior to attachment.
In a future rehabilitation, it may be necessary to gather coral fragments
from locations quite far away (perhaps tens of kilometres) from the area
to be restored and ship them in. Because this may involve many thousands
of fragments, two methods of handling were examined. Fragments were either
collected and stored for two hours in baskets in the lagoon, or were covered
by a wet canvas tarpaulin and stored for the same period of time in air
in a boat. Clearly for transportation purposes, the second method if successful
would be the simplest and most cost-effective. All coral fragments treated
in these ways were compared with controls which were branches of corals
left attached to their parent colony but which were marked at the location
from which they would have been severed had they been removed to provide
a fragment.
All fragments and controls were monitored for growth, mortality,
bleaching, numbers of tips and whether they had made an independent attachment
with the substrate.
These treatments were applied to five species of corals which were chosen
because they display a range of characteristics and may, therefore, provide
some insights into the responses of a wider range of species present on
the reef. The species examined included branching, finger-like, solid
and delicately-walled tube-like forms, as well as a soft-bodied gorgonian
coral (sea fan). Some of the species are considered robust and fast-growing,
while others are sensitive to disturbance or relatively slow-growing.
The results of this preliminary experiment show that wholesale
reintroductions of coral fragments may prove to be a useful, though expensive
tool for restoring coral reef areas. Attachment by cement, although more
difficult and expensive appears to be superior to the use of nails and
cable ties, possibly because the cement holds fragments firmly, allowing
greater opportunity for attachment and reducing the risk of abrasion against
other surfaces. For most species, exposure to air for transportation was
a disadvantage.
.The cost of full rehabilitation with a target density of 245,000 fragments
per hectare has been estimated at $580,000, plus ship time. However, replacement
of 10% of the density might cost around $58,000 plus ship time, which
may be a justifiable amount in a medium-scale restoration.
The results of this experiment have identified the focal issues
and set the stage for future work on the development of techniques needed
for the successful reconstruction of disrupted coral reef habitats. Further
experiments are now being carried out on the effects of timing, source
colony and other factors on the rates of success of transplantations of
corals. Future research should be aimed at carrying out experimental rehabilitations
to determine how effective our efforts are at accelerating the process
of regeneration of damaged coral reef areas.
This study provides the industry and management with preliminary
information about the efficacy of restoring coral reefs which have been
damaged. This will be particularly useful in cases where a tourist site
has been compromised by natural causes such as cyclone or crown-of-thorns
starfish. The increasing level of tourist activity and associated infrastructure
such as pontoons will mean that, in the forseeable future, moving a pontoon
to a new site following degredation at a present site will not be as appropriate
as it has been in the past. Knowledge of the best methods of rehabilitation
and the associated cost is, therefore, particularly relevant to industry
and management.
THIS PUBLICATION IS CITED AS:
Kaly, U.L. (1995).
Experimental test of the effects of methods of attachment
and handling on the rapid transplantation of corals.
CRC Reef Research Centre Ltd
Technical Report No. 1
Townsville; CRC Reef Research Centre Ltd, 28 pp.
ISBN 0 642 22767 5
A full copy of this report may be obtained from the author(s),
and through the following libraries:
Agency libraries: Great Barrier Reef Marine Park Authority,
Townsville; Australian Institute of Marine Science, Townsville; James
Cook University, Townsville; Queensland Department of Primary Industries and Fisheries
(Brisbane and regional offices); Queensland Department of Environment
and Heritage (Brisbane and regional offices); CSIRO Division of Marine
Research, Tasmania.
Public libraries: Queensland, New South Wales, Tasmania and South
Australia State libraries; National Library, ACT.
Parliamentary libraries: Queensland, New South Wales and South
Australia parliamentary libraries.
For a hard copy (or pdf file) of the report contact CRC Reef on info@crcreef.com.
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