Artificial Reef Building

[CBulla]

Hey buddy.. check out this site - http://www.artificialreefs.org/

I'll try to find a pic of the jacks...

The tetrahedrons are here at my counties website: http://www.lee-county.com/naturalresources/arc.htm

Also visible is the radio tower that was dropped on that site (actually 3 sections) with grouper hangin out on it.

 

[archman]

Hey buddy.. check out this site - http://www.artificialreefs.org/
The tetrahedrons are here at my counties website: http://www.lee-county.com/naturalresources/arc.htm

Those are "reef balls". Pretty good functionality, but almost certainly outside the scope of babydamalug's experiment. The molds and parts kits are expensive, and you have to mix the concrete yourself. Plus even the tiny-sized models weigh a bloody ton. I built a few of those this summer on Eleuthera, man what a workout!

 

[Babydamulag]

Roger that....reef balls are outside the scope of this effort. We are looking for something the paying tourist can do on a vacation an get a "warm fuzzy" about while helping the environment and helping us restore some reef to our area.

I am thinking of a rectangular shape with notches (in and out) on the sides and ends.

 

[DavidPT40]

There is an artificial reef that is made out of plastic. It comes in about 3 foot by 3 foot segments. Its supposed to look kind of like branched coral. The idea is that the plastic reef will become encrusted in calcium carbonate or other hard materials before it deteriorates. I think some of the pacific islands have had success with it. I'll try to find a link.

 

[Babydamulag]

Does anyone have the information about the "plastic" artificial reef material? I saw it once and I am like DavidPT40....can't find it!!!

 

[archman]

Perhaps it's "EcoReefs" you're thinking about. These are very pretty looking (and very expensive) alternatives for branching coral restoration. They are made from ceramic of moderate longevity, but the expected lifespan of <20 years leaves a lot to be desired. Also, minimum orders of these things are required by the company that makes them.
http://www.ecoreefs.com/home.php

Plastic sucks. Really. I am unaware of any plastic-based technique designed to last an appropriate period of time.

 

[DavidPT40]

Thats what it was, EcoReefs. So the EcoReefs don't gain any structural support from the coral growing on them? Twenty years really isn't that long considering the age of most reefs.

I've had some experience with artificial reef building on a small scale. I used a mixture of portland cement, sand, and crushed oyster shell. I'm not sure about the copyright or patent infringements, but I think something similar to the EcoReef could be made in about 5 hours if the appropriate molds were laid out and there was a large enough oven to put it in.

I've heard that pvc will quickly become encrusted by marine life, but that pvc also degrades quickly in seawater. So when the pvc is gone, is the calcified marine life strong enough support itself?

 

[archman]

Thats what it was, EcoReefs. So the EcoReefs don't gain any structural support from the coral growing on them? Twenty years really isn't that long considering the age of most reefs.

Ah, here's the caveat. IF the artificial structures get sufficient coral settlement. Getting a few colonies to overgrow a structure is one thing, having them form self-sufficient bioherms is another pickle entirely. That takes a lot more time, and is far more finicky. A lot of the "easy colonizers" like mustard hill or lesser starlets don't form significant substrate, and their presence on the artificial stuff can give folks false hopes. And it's not just corals that create the reef, but one has to factor in the cementing coralline algae as well. The fill in the interstices between adjacent colonies, and are what "glues" most natural reefs together.

I've heard that pvc will quickly become encrusted by marine life, but that pvc also degrades quickly in seawater. So when the pvc is gone, is the calcified marine life strong enough support itself?

Sunlight kills plastic, as most divers well know. Light attenuation from being in the water only slows the degradation down. Plastic is also a poor settlement material, as it is very smooth, and often toxic/distasteful to larval recuits. It's only advantage is that it is cheap and weighs little. But once it gets brittle, it will fall apart for a nothing.

 

[gonetobaja]

Archman,

I have heard of alot of ships being sunk to provide for reefs over here off the coast of CA. I had an Idea to put a bunch of old cleaned up car frames (no plastics or petroleums) in a pile at the bottom in about 40 feet but you said that metal is no good for reefs. Do you mean only coral reefs? If so, is it a good idea for me to put the car frames in the area for fish habitat? There are areas where there is no rocks and it would seem to have the same fish attracting properties as a sunken ship. I would be building this reef to add fish habitat. There are alot of old cars down here in Baja.

Is the metal a bad Idea period or just for the coral?

GTB

 

[DavidPT40]

I know that the Gulf of Mexico has massive amounts of junk metal thrown everywhere to create artificial reefs. Bridges, hovercrafts, stoves, cars, tanks, all kinds of junk.

However, there is a debate whether or not artificial reefs contribute to the fish population. Sure, they attract fish. But so do reefs in freshwater. The argument that I read was that a series of artificial reefs would need to be constructed, following the current, so that larval fish and invertebrates would have some place to colonize when the current carried them off.