Artificial Floating Coral Reefs


This is my general idea for artificial floating coral reefs, like the topic title says.

The basic reef unit would be a column, with a float (I’m thinking a 55 gallon drum or some other big floating device) and a weight at the bottom, to keep the column upright. Between the frames would be a trellis structure, with different beams and sections of fencing and such to create different surfaces with different spacing. Corals could by propagated onto this and allowed to spread naturally, or position the empty columns adventurously during the annual coral spawning to get as much new growth as possible. These columns could be used to create a floating reef around the main seastead, and would be unaffected by rising sea levels, since they float (they would, unfortunately, be vulnerable to other effects of climate change such as ocean acidification, changing temperatures, and changing salinity due to the melting of glaciers). They could be used to create artificial reef in any depth of water, they would just need to be connected to each other and the seastead, perhaps by more underwater connecting trellises. This would also allow us, pending on how we attach them, to create new reefs, change the structure of our old one (to create new harbor channels, for example), or to build connecting reefs to nearby seasteads. Perhaps on the seastead itself, the buildup of solid rock would protect the hull against some of the natural elements, increasing the lifespan of the seastead.

This would drastically increase the productivity of the region, since open ocean could suddenly support much more life, and the seastead would also benefit from tourism. Imagine snorkeling in clear water looking at coral reefs, with a blue fade-out background beneath. I think it’d be pretty cool at least. Also, they could help buffer the seastead from storms and provide natural protection against raids on all sides except where the harbor channel(s) would be.

I would also think the design could be used to support other varieties of marine life. Pending on the location of the seastead, the bottom barrels could be used for kelp, and the hold-fasts would safe from sea urchin attack. Perhaps other sea grasses could be planted in some specially designed one, which would also increase the variety of life and productivity of the region. Kelp as a plant has many practical uses for humans as well. Perhaps we could get our own paper through harvesting kelp, since it can grow pretty fast.

I am also considering testing if a similar design could host mangroves (I don’t know if they get their nutrients from the mud or not, since it is fairly anoxic among other things. I read somewhere that they get a lot from the roots above water or something. This is why I will test.). These would help a seastead immensely, since we could get wood (for whatever mangrove wood is actually good for…), as well as perhaps making a solid ring of floating mangrove forest around the seastead, to act as a natural storm break, similar to their role on land. Picture it like a target, with the seastead as the bulls eye, the coral reef as the next concentric ring, and the mangroves around that. Lots of protection and lots of habitat.

(Matias Volco) #2

Yes! Talk about collective mind that’s exactly what I was researching at the moment. If a breakwater is necessary then it can naturally function as a coral reef, under the right water conditions.
Residential real estate could have underwater gardens as well as “green space” above.


Dr. Austin Bowden- Kerby came up with the following simple method to restore and grow coral reefs. His work in Fiji with was the main inspiration for the design of my Reefstead.

(Chad Elwartowski) #4

Look into Biorock. It is the process of using a small electric current on metal in the ocean to grow rock around the metal at the rate of 5 cm per year. It has also been found to be perfect for growing coral and coral even thrives on biorock while in the same conditions that other coral is destroyed.

(.) #5

I have a 15W solar panel. I use two 1ft rebars as electrodes.
Seacete grows.


The biorock sounds good, since we could mount solar panels on top of the floats too.

Also, any feedback on the mangrove part of the idea?

(Matias Volco) #7

I have, but I wonder if anyone has ever tried a completely floating seacreate structure, without touching the seafloor.
We’d still have the initial cost for the floating structure, at least one as breakwater, from it, it can a seacrete structure could extend from, if necessary.


I don’t know, but the mangroves wouldn’t necessarily need to touch the bottom. As long as there a quite a few of them and the forest locks together pretty well, they would act as a pretty good breakwater.


I think it can be done. Imagine building a float that will act as a “mold”. (even a really cheap one made of marine plywood would do). Now, wrap the bottom and the topsides of the float in few layers of chicken wire (like they do in ferrocement construction), drop it in the water and run current through the wires. In time, the seacreate will form on the wires and little by little will fill and close the loops in the chicken wire, thus creating a hull around the float. From time to time re-wrap over the existing secreate until the desired thickness of the hull is achieved.

At this point, remove the float-mold. Since lighter now, the hull will float at a different WL (water line), bellow the previous one, thus giving you a certain amount of freeboard to work with. Now you can build anything on top of that hull :smile:

But it will be a slow process,…

(.) #10

Biorock is interesting. I think it is mostly magnesium and calcium an carbonate and sulfate.
It takes an electrochemical process to make the biorock precipitate. It seems like
the determining factor is the solubility constant of the precipitatin solid.
Seawater if full of sodium and chloride too, but I think, as sodium and chloride salts
precipitate, they desolve back into the water. Mg, Ca, CO3 and SO4 salts are in less
concentration in seawater, and for that probably the circulation of seawater around the
electrodes, is beneficial for growth.
I have to make sure, but I think it is the negative electrode where the rock precipitates,
the other electrode gets desolved. Finding an inert electrode might be beneficial.
A biorock covered electrode still works because the rock grows on the electrode.
That is an interesting phenomenon for me. I wonder if I make a concrete covered electrode
would biorock precipitate on the electrode or on the surface of the concrete, or within
the structure of the concrete.
I am planning to make a concrete foam covered electrode and check what the biorock does.
It would probably be possible to grow ‘honey comb’ structural elements of biorock under water.
When the structural element is the desired quality, then float it and connect them to
make a larger floating structure. It still takes iron. ( steel) (rebar) (electrodes)
I wonder how the seashells do it.
I wonder if the precipitating process is different in the deep water beacuse of the pressure.
Anyways, over and ou t.

(Matias Volco) #11

Then perhaps not a single strategy but competing and complementing ones.
wire mesh is definitely a lot lighter than concrete. If a micro greed ever generates excess power that cannot be stored or circulated then it could go into seacreating as if it were ground.(could it???)

(.) #12

Yes, the mangrove:
Small stems float in water to shore.(saltwater)
Than they root into the sand and grow.
I am going to get some and put them in a floating concrete covered styrofoam.
I will drag it around with my sailboat.


I guess you can host mangroves if the floating reef is located in well protected and very calm waters. But otherwise, you will always have waves breaking over the mangroves and eventually have all the soil that they were planted in washed out.

(.) #14

Saltwater hydroponic mangroves.


The question is whether or not they actually need soil to grow? I know they have huge amounts of muck about the base, but it is apparently anoxic, so there isn’t much decomposition to turn it into nutrients. Also, that only develops after the mangroves have grown, they start rooting in sand, which isn’t necessarily the most nutrient rich soil. If you could put a float around the stem of a mangrove, would it keep growing with no bottom under it? That is the question that needs answering.


LOL,…they do need soil.


Well that’s a pain in the ass. There is still probably a decent way to get a mangrove barrier at sea. A giant shallow underwater planter filled with muck?


Forget about the mangroves on the open sea,…

(Wilfried Ellmer) #19

completly agree - to get a picture what you need to prepared for when talking about open sea check here

This is the reason why mangroves and no other plant or animal is making a home on the open sea surface - the open sea surface is a biological desert because it is too violent to allow anything to grow there. All animal life is going on below the waves.


If mangroves could grow independently on the ocean surface the ocean surface would already be covered by them :stuck_out_tongue:

Interesting post about biorock, I’d heard of it before but didn’t know much about it. Has anyone experimented with actually creating a watertight hull out of the stuff?

To bring something to the table: If you’re in shallow enough water, kelp forests might help as a first line of defence. Obviously they won’t crunch a monster wave but they could do alot to reduce the smaller ones, and if they get damaged, they regrow much quicker than coral. They’re also extremely rich biomes and host all kinds of animal life.