Why are Reef Balls
better than other artificial
reefs?
Reef
Balls are superior to many other materials for the
following reasons:
1) An
artificial reef should not contain toxins that leach
into the sea water.
Tires
are known to leach petroleum compounds and other
nastiness. Some older military ships contain large
amounts of PCBs. Many "Materials Of Opportunity"
(i.e. cars, barges, etc.) contain
toxins.
2) An
artificial reef should not contain biologically active
compounds like copper, iron, zinc, chromium, or
fertilizers.
Steel
objects favor the growth of marine plants and
invertebrate that need iron. Although this stimulates
the growth of some species, it does not stimulate a
natural growth and the species diversity and densities
will not mimic natural reefs.
3) An
artificial reef should remain stable on the bottom and
last for hundreds of years.
Many
objects are just too light or have too high of a profile
compared to their weight to remain stable on the bottom.
These objects will move around in storms tearing up the
natural reefs as they move. In the process of moving,
the growth is often lost. Even when the growth remains,
it is oriented differently to sunlight and currents and
may die.
If the
objects don't last long enough (i.e. steel rusts) the
corals that settle on the structure just fall off. Many
corals don't get to adequate spawning sizes until they
are over a hundred years old. So if the goal is to help
coral ecology, short lived materials are not
suitable.
4) Reef
Balls Are Designed For The Life They
Support
Reef
Balls have holes that not only go into the module but
between the walls. The large open area in the center is
designed to provide fish shelter. The holes are designed
to create vortexes which feed the invertebrates and
corals. Many other artificial reefs assume that surface
area or profile alone will support fish. Profile only
attracts (but does not support) certain types of fish.
Raw surface area without the right composition is just
dead space (surface area needs current, light or both to
be productive).
5) And
a real reason Reef Balls are best is
cost.
The
cost to hire a barge and crane for a single day is
generally at least $10,000. Without the option for a
floating deployment style, even "materials of
opportunity" are too costly. When all costs are
considered, Reef Balls are the most economical designed
artificial reefs the in world.
How
Should I Deploy My Reef Balls
Many
people want to know if the Reef Balls should be spread
out or piled high. Deployment patterns have a major
effect on the type of life that will use your reef. Only
the goals of your project can best answer the question.
In absence of goals, just arrange your Reef Balls in a
pattern similar to your observations of the natural
reefs in the area. Dr.
Bill Lindberg is studying deployment patterns now
and can probably assist if your goals include the
recruitment of specific fish species. Generally however,
fishing reefs are better spread out and diving reefs
need to be tightly deployed. A combination of the two
makes an excellent reef.
Why is
pH Neutralized Concrete Important (What's Microsilica
For)?
Regular
concrete has a high pH when it is first cast. This is
caused by excess calcium hydroxide in the concrete. Over
time in water (or even rain) the calcium hydroxide
slowly leaches out. Eventually, the pH of the concrete
in the sea will approach the pH of the sea which is
about 8.3. However, this leaching (which takes about 3-6
months in sea water) is toxic to many types of marine
life. Some types, like barnacles, are resistant to the
pH difference so the growth that occurs on concrete that
is not pH neutralized will favor those species. By the
time the pH is normal, the resistant species have
settled and set up defenses to repel settlement of other
marine life forms to the reef. We recommend that if
microsilica is not available that you let your concrete
cure in the rain or a freshwater pond for about 3-6
months before deployment. If microsilica is available,
the correct dose will bring the pH to about 8.3 right
away. (Microsilica reacts with calcium hydroxide to form
a type of cement "glue" that actually makes the Reef
Balls stronger).
How Do
We Insure Stability?
Many
clients ask us how to anchor their Reef Balls. First, it
should be understood that Reef Balls were designed so
that they would NOT require anchors unless in shallow
high energy areas. In most cases, the weight
distribution and hydrodynamics of the modules will keep
them in place through even the worst storms. However,
any object in the ocean can move under extreme
conditions and the direct hit of a major hurricane is
nearly impossible for any object to withstand. If you
feel that your reef needs anchoring, we have developed
several techniques to make it easy. To make attachment
points, just use a 1/2 inch stainless steel I-bolt with
a large washer attached to the end, and place it between
the side flanges about 6 inches above the bottom of the
mold. You may need to drill a hole right at the flange
joints for large bolts. Leave the circle in the I-bolt
sticking out of the flange. You can add as many of these
attachment points as you need for
anchors.
Now,
you just need to select an anchor and attach it to the
I-bolt. We suggest the use of stainless steel airplane
cabling to connect the anchor to the I-bolt. House
trailer tie down anchors are inexpensive, but may only
last 10-20 years. Double helix anchors are available
that have a much greater holding strength, but they also
cost more.
Another
trick is to wrap a house trailer tie down anchor (just
the bottom screw part) in a paper bag with sand in it.
Coat the shaft with several layers of sugar water,
letting each layer dry. Position the anchor in the mold
just like the I-bolt at a 45 degree angle leaving a foot
or more sticking out of the flange. After casting, flush
the shaft with a garden hose to make sure it breaks free
from the concrete. On the ocean floor, just tap the
shaft into the sand. Then screw it in
tight.
Did
They Really Outlaw The Use of Cars In
Alabama?
As of
January 1, 1997, car bodies are not allowed on the large
area permit in Alabama. Car bodies have never been
legally allowed on Florida's LAP.
Can
PVC Plastics Be Used As A Reef
Material?
Yes,
the Army Corp of Engineers still allows the use of PVC
plastics in the construction of DESIGNED artificial
reefs only. PVC, however, has a charge that attracts
bacterial microbes which can cause an unnatural
settlement of marine growth. PVC is also known to be
light weight and brittle--often breaking down with age.
The only artificial reefs currently using PVC are
experimental or fitted with large concrete slabs for
stability. Even with the concrete, PVC reefs have not
yet been proven to be long lasting. Occasionally, Reef
Ball allows the use of PVC air filled capsules encased
fully in the top of our Reef Balls. The purpose of this
is to provide a highly visible "signature" on depth
finders to easily locate Reef Ball reefs. These capsules
are not intended to be exposed to the open
ocean.