Artificial reefs & their placement
Practical Action
After the community has agreed to go ahead, there are two main phases to creating the
artificial reef: construction, and placement.
Construction
Variety
It is important when constructing the reef to
provide as much diversity of habitat as
possible, as this encourages the greatest
diversity of species. The greater the
biodiversity living on the reef, the healthier the
reef will be. Use many different types of
modules, including well rings, ferrocement
modules, tyres, granite boulders, coconut
stumps, poles, pipes, bottles, and whatever
else is available locally. Use them in a variety
of combinations and orientations.
Current
Artificial reef materials placed
across the current
Clusters
It is important to cluster plenty of material together
densely; the more the better. Very dispersed materials
will not be colonised successfully, and will only be
wasted. (See later for a suggested technique for
placement.)
Transit
buoys
Anchor 1
Orientation of the clusters is also important. Line
structures or clusters should be placed so that they are
Current
across the current. This provides a sheltered environment
for smaller fishes, and a ‘standing wave’ above the reef,
which throws up food for a variety of species. Before you
begin placing the reef material set two marker buoys in
the water and a land transit to give you an approximate
Anchor 2
line to follow.
Reef modules
on seabed
Placement rig
Crevices
Ensure that the reef that you are creating has plenty of
holes and crevices to provide refuge and shelter from
predators and current. The greater the variety of size,
density, and orientation of the crevices the better, as they
will shelter a wider variety of creatures. Crevices can be
created in a number of ways, usually by leaving holes in
fabricated modules or attaching materials such as broken
pipes to the modules to create holes. Whole or broken
pantiles, bottles, cooking pots, buckets, flower pots, and
bricks are just some of the many items that can be ‘glued’
onto modules to create interesting crevices. It is also
important to attach natural or synthetic fibres to the reef
modules. They make a very attractive substrate for the
smallest of creatures, and are ideal places for cuttlefish to
lay their eggs.
Height
It is recommended that reefs should be about one-third of
the water depth. If that is not possible, then you should
at least introduce a number of taller modules into the
reef. Height makes it easier for roving predatory fish to
locate the reef, thereby increasing further the biodiversity
of the reef. The reef will act like a beacon, and in times
2