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Preparation of the moulds |
Artificial
Reef preparation and construction is an ongoing process at TRACC,
some part of the process happens for 6 from the 7 days of the week.
This week, our Malaysian staff and volunteers were building more
bottle reefs in the moulds. The moulds are lined with plastic to
stop the cement sticking to the wooden sides or becoming dry by
losing all the moisture down into the sand floor. Each mould is
about 10ft long, made of a wooden frame. The cement is mixed by the
very nice new mixer bought with the support of the Small Grants
Programme of the Global Environment Facility (SGP/GEF). The mixture
of sand and cement is a wet mortar and we use a plasticizer to give
the mixture more workability. The sloppy mortar mixture is poured
into the moulds and then the bottles can be added.
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Bottle reefs waiting for the cement to set overnight. |
Each
bottle is pre-cleaned to remove the labels and any residue of
contents. We only use bottles which have contained food or drink so
that there is no risk of pollution from the bottle contents.
The
bottles are rolled in the wet cement mortar so that they have a
slightly roughened surface from the cement and sand. When this layer
is hard it helps the attraction and settlement of a wide variety of
sedentary reef building organisms such as sponges, ascidians byozoans
as well as hard and soft corals.
The
bottles are worked into the bed of mortar so that they stand upright
and are submerged by 3-5 cm in the wet mortar. Generally the bottles
are positioned about 7-12 cm apart. If they are too close then it is
hard to make the block so that it doesn't fall apart when it is set.
If the bottles are too far apart, then the coral fragments or
biscuits could move out of the protective ring of bottles and fall
into the sand. All sizes and shapes of bottles can be used; from
jamjars to ketchup to beer bottles.
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finished bottle reefs after the cement has set. |
Plastic
water bottles are not normally used because they can come out of the
cement base when there is wave action. Fizzy drink bottles can be
used but we puncture holes near the base so that the cement mortar
goes into the bottles and helps to lock them into the bottle reef
block. Most of the bottle reefs for coral planting use only glass
bottles which are not in short supply. Glass is not recycled in
Sabah because of the cost of shipping to Peninsular Malaysia.
Consequently there are plenty of bottles which are donated by caring
citizens or businesses.
The
raw material for our artificial reefs is cheap and plentyful and with
photos and videos of the results from our SGP/GEF project near the
Tip of Borneo (Simpang Mengayu) and on Pom Pom island near Semporna,
will lead to more community action projects around the region using
the techniques we are developing to improve and rebuild the reefs
close to each village.
More info about learning to dive or volunteering to help save the ocean with TRACC in Malaysia - Turtle Snorkellers - Divers