Reef rehabilitation across the globe

Hi Viper,

Very interesting link!

Has anyone heard of the South African Underwater Ecology Society? The email address given bounces and the links on DEAT's site also no longer function.

 

Yes I saw a documentary on them long ago. Very interesting work being done.

 

Hi Guys

Check out this for the rehab and construction of new reefs

http://www.globalcoral.org/photo_galleries.htm

To do this in our confined tanks appears to be a no-no as the processes leaches chlorine gass and some bad acids but. I spent hours surfing on this last night and even traced the patent, to start we need to look at this, imagine do this at Vetchs pier.

Carl

 

Reef Balls

I spoke to Don Hourahane (he lives/lived in Roodepoort) some years ago, he spoke of a project in New Zealand. As far as I know nothing came of it. The materials used, are apart from the roving, are the same as many of us are using to make artificial live rock, namely cement and some form of calcium carbonate or aragonite.
I did see a program where the Americans were spending millions of dollars removing the "artificial reefs" made of old tyres which are causing an ecological disaster on the Florida Keys.

 

I recently saw a program on a society also creating artificial reefs from plain old iron bar. I think there is a thread here on MASA about it.

Within a couple of weeks the iron is covered in coralline and within a matter of two days the iron structures are teaming with shrimp, crabs, small fish and other crustaceans. It was amazing to see a structure made of rebar go from nothing to a full blown reef with SPS, anemones and lots of other life.

 

Hi Rod

Good to see you here.

This form of artficial reef is using a metal frame with some low voltage DC trough it.

It uses the mineral accretion, or the Biorock® Process, by Prof Wolf Hibertz.

Copied from his website

Mineral accretion technology is a method which uses safe, low voltage electrical currents through seawater, causing dissolved minerals to crystallize out on structures, growing into a white limestone similar to that which makes up coral reefs and tropical white sand beaches. This material has a strength similar to concrete. It can be used to make growing artificial reefs on which corals grow at very rapid rates because the change in the environment produced by electrical currents speed up formation and growth of both chemical limestone rock and the skeletons of corals and other shell-bearing organisms.

Check his site:
http://www.wolfhilbertz.com

See you soon

Carl

 

carl some nice studying there man!! very very interesting!!

 

Phat

you guys on the sea can we come build areef for you

Carl

 

with pleasure dud but slums water is to cold

 

One thing with artificial reef, or any other artificail habitat or rehabilitation programme, is that you never have any certainty about what the outcomes will be. For example, Vetch's Pier is an artificial reef that was constructed (albeit as a breakwater for the harbour) some 100 years ago. What is interesting is that Vetch's and Limestone (the natural reef that Vetch's links to) are reasonably similar but that the existing North breakwater at the harbour entrance is very different. The breakwater is constructed of rock that is very similar, if not the same as was used for Vetch's, and, whilst it is not as old as Vetch's reef, it is not nearly as species rich. Long and short of it is that there is more to creating reef than placing some structure into the sea.

As an aside creating reef is all very well and good, but it does usually come at the expense of a perfectly good sand habitat with its own ecology.

 

Hi Carl that is really interesting. I see that the advantage doesn't last if the current is switched off. I would love to see someone try it in an aquarium. You checked out the patent?

 

Hi Rod

Heres an abriefed version:

Patent - 4,246,075, Hilbertz, W.H., Mineral accretion of large surface
[SIZE=+1]structures, building components and elements[/SIZE]
[SIZE=+0]Jan. 20, 1981.[/SIZE] Summary: Wolf Hilbertz' first patent on the process of seament
production by electroaccretion. By topic heading:
I. Background of the Invention - A very brief summary of the mineral
content of ocean water and past attempts to utilize electrodeposition of
minerals for corrosion protection of metallic marine structures.
II. Summary of the Invention - A description of Hilbertz' proposal to
use shaped metallic cathodes as accretion forms for the creation of
building components. So far as electrical power requirements, he states
that the: "...current may be of a density of up to 15000 mA/sq.ft. with
an electric field potential between the electrodes of up to 30,000 volts."
III. Detailed Description of the Invention
IIIa. General Discussion - A description of the mineral content in ocean
water and their use by living organisms. Non biological mineral
extraction methods such as stalactite formation and electroaccretion are
described in terms of the chemical and physical mechanisms. The
results of X-ray diffraction analysis of sea water accreted material is
given. The composition of the electroaccreted material in Hilbertz'
experiments turned out to be mostly Mg(OH)2 with small amounts of
calcium compounds.
IIIb. Electrodeposition of Minerals onto Large Complex Surfaces as
Structures - This section contains some descriptions of electroaccretion
test runs. Steel mesh was used as the cathode material. Listed as
possible anode materials were : "...iron, steel, lead, platinum,
columbium..." A test was described where the voltage applied between
the anode and the cathode was 6 volts and the current density 189
mA/ft2. After an accretion time of 170 hours accretion thickness on
the cathode material ranged from 2.5 cm to 2.3 mm. Hilbertz states the
general rule that the slower the accretion rate, the stronger the resultant
material. Phasing, the alternation of electrodeposition with biological
accretion is described briefly. No claims were made so far as this
producing materials with superior structural properties. The
possibilities of having the cathode and anode alternate roles by
reversing the electrical drive polarity was briefly described as a
possibility without detailing any experimental data on this technique.
IIIc. Specific Engineering and Architectural Applications - In this
section Hilbertz describes a proposal for electroaccreting structures for
OTECs, repairing them in place if they suffer damage and pumping
water by electrolytic bubble lift.
IIId. Advantages of Mineral Accretion Technology - The principle
advantage claimed over conventional construction technology for
marine applications is the ability to effect in-place repair of the
structure.
IV. Claims - three pages of legalese detailing the process of
electroaccretion of structures in fluid electrolytes such as sea water.


Carl

 

There is a "reef" called junk reef a little further out from Limestone reef. This is where rubble and old cables etc was dumoed many years ago. There is not much there with regard to corals, but the fish are teeming there.
So as Carl said, there is more to building a reef than dumping the "base" there.

 

Nope, the tyres is a haven for shrimp and big eels. Junk reef is further out to sea.