Guidelines for design of artificial reefs - request for

nadav shashar nadavs at cc.huji.ac.il
Sat Jan 5 04:28:31 EST 2002


comments
Sender: owner-coral-list at coral.aoml.noaa.gov

In Eilat, Israel- on the northern tip of the Red Sea a plan is going on to
construct an artificial coral reef on some mostly sandy areas (near the
north beach for those who know the area). The main purpose of the
artificial reef is to serve as a divers attraction and to divert pressure
away from natural reefs. Secondary goals are providing shelter and place
to grow for reef organisms and possibly increase biodiversity and
recruitment on natural reefs. A whole set of guidelines are being prepared
as to insure that the artificial reef will not damage the natural
environment, etc. We are planning to put out a call for designers,
architects, students etc. and to place a competition (with prizes) for the
design of the artificial reef or for large units in it. For this I would
like to ask your help in setting the guidelines for this design. Please
note that the main focus of the guidelines is environmental preservation
and safety. Artistic issues for example, are not taken into account.
Please take a look at the following guidelines and comment on them. Please
reply directly to me (no need to bother everybody). I you are interested
in the final copy of these guidelines let me know as well. I thank you all
for your time and effort Sincerely Nadav Shashar

Nadav Shashar  - Ph.D.
The Interuniversity Inst. for Marine Sciences
P.O. Box 469, Eilat, 88103     Israel
Phone: (972)-8- 6360111
Fax: (972)-8-6374329
E-mail: nadavs at cc.huji.ac.il
http://www.iui-eilat.ac.il/nadav.htm
--------------------------------------------

Guidelines for the design of artificial reefs and artificial-reef units

Each unit will be designed, built, and placed such that if needed it can
be taken out of the water using technology and equipment available at the
local area (city, town, etc.). In essence, each unit will come with its
own hook or ring to be used for pulling out attached to it. The funding
for such extraction will be provided and set aside in advance.

The materials used will be only materials PROVEN to have no harmful
effects on the environment and on marine organisms. This applies to
materials themselves and to any breakdown product that can be expected to
occur during the existence of the reef in the water. No oils, antifouling
materials, paints or other coating materials will be used.

Artificial reefs are items planed for existence for generations to come.
Therefore, the design, material, and structure, should be durable for a
long time. For planning proposes, one should plan on durability for 100
years from deployment. This planning should take into consideration
corrosion, effects of storms in the scale that occur at the location of
deployment, boring of animals, etc. The strength of the structure should
account for additional weight by growth of corals on it. Covering of the
structure by corals and other creatures should not be considered as a
strengthening component.

The structure will be complex on multiple levels to provide habitats to a
range of organisms. This complexity means having numerous holes and
crevasses in a range of sizes from 3 cm to 50 cm in diameter, use of
surfaces at different orientations (vertical, horizontal, and slanted at
different directions), use of flat surfaces as well as smaller "wire type"
circular polls, etc. Whenever possible, smooth surfaces should be avoided.

Certain regions of the reef, having high structural complexity, will be
physically blocked away from visitors' (mostly divers) accesses. This is
to provide animals, mainly fish, living on the reef, a refuge from human
intervention.

The reef will be planed to minimize blocking of water currents in its area
and of sand movement near the bottom. Passages and holes will used to
allow water flow through it and if needed it will be placed on stands to
lift it from the bottom. No area or region of the artificial structure
will be blocked from the open water such that to prevent water
circulation.

The design will prevent the accumulation of sediments on it. Slopes,
holes, vertical walls, gaps, etc. will be sued so that sediments will fall
to the bottom of the sea.

Height of the planed structure should be at least 10 m above the bottom.
It should be expected that there would be very limited coral settlement on
the lower 2 m- mainly due to the effects of sand. If the structure is
planed to come close to the water surface- limited if not null coral
settlement and growth should be expected in the top 2 m- due to storms and
waves actions.

The design should be attractive to visitors (divers) from the day of
deployment without depending neither on coral growth nor on fish
populations. This attractiveness should not be reduced or diminished due
to erosion or other long-term effects of being submerged, nor due to
growth of algae, coral or other organisms on it.

Portions of the artificial reef, located at different depths, will have
large horizontal surfaces to allow groups and classes of divers to stand
on, or to perform practices. The artificial reef will be planed to require
no or minimal amount of maintenance, and such that most such maintenance
will be modular.

The reef will be planed and built with outmost concern to safety. All
passages will be designed to prevent divers from being caught in them and
free easy accent should always be available. The design should also take
into account and prevent trapping of sea turtles, dolphins, or other large
animals.

All parts of the reef will be planed and set such that they can be lowered
from a ship/ barge without needed side chains, sinkers or other means that
might negatively affect the surrounding area.

The total area occupied be the artificial reefs will take no more than 20%
of the over all area available for the park, and all of this area will be
considered affected by strong human intervention.

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