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Coral Reef Health and Sustainability

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Coral Reef Health and Sustainability

A forum dedicated to the sustainability and health of Fiji's precious Coral Reefs.

Members: 5
Latest Activity: May 15, 2013

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coral reef gardening 10 Replies

I could do that ie tend reefs tyContinue

Started by Margaret Chabaud. Last reply by Roberta Davis May 15, 2013.

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Comment by Roberta Davis on March 17, 2013 at 12:33pm

We have been involved in reef gardening for the last 3 years.  It has been a real learning curve and we are starting to formulate new ideas to implement artificial reef structures to plant in areas that are deeper and not so prone to storm surf damage.  So anyone with any questions or ideas, please share with us. 

Comment by Robert F. Kay on March 17, 2013 at 12:35pm

Thanks Roberta...we hope to get more people involved in this forum to trade idea...

Comment by Coral Diver on March 17, 2013 at 6:30pm

I actually have dreams for doing this on a big scale some day... I have an idea on using your standard roof guttering as moulds for underwater reef structures and connecting them from bommies to other bommies (adjusting length accordingly), and adding spaces for corals and other inverts... what you think

Comment by Roberta Davis on March 17, 2013 at 8:39pm

It kind of depends on what your reef structure looks like and how prone it is to high surf.  Our first attempt  after Hurricane Tomasi that was very successful up until the storm surf in November was just fitting the broken  coral cuttings snugly into holes in the existing dead corals.  THey take root in about a month and then start growing rapidly.  If your area  doesn't have much coral then try to find the branching staghorn type corals and plant them along the sides and tops of existing formations to create homes for the little fish to hide in and start your ecosystem.  The worst case scenario which we found after the latest storm surf is we had lots of cuttings to replant again.  Tell me a little more about the area you want to plant in and what it looks like out there.  I might have some ideas for you.  It is so much fun to do and addicting watching your reef grow is amazing!!!

We also are devising Plan B right now of creating reefs in sandy areas, we are leaning towards making frames out of PVC and planting them deep enough so they can survive the storm surf and where we don't have to worry about metal frames rusting out.  What we are trying to do is determine the weight bearing threshold for the structure. 

I was actually playing with the idea which sounds similar to yours with the pipes is figuring out a way to secure shorter drainage pipes or connect them off the PVC structure to create an octopus garden.   Anyway give me some ideas of what you are up against and we can brainstorm.  I am waiting for Scott also to join this forum because he is very smart and has been helping me out as a friendly consultant since we began. 

Comment by Coral Diver on March 18, 2013 at 9:55am

I have actually tried the method of broken coral cuttings, including the one with staghorn corals... apart from fitting them into holes, you can also plant one on top of the other, I know this is not standard coral gardening procedure as corals tend to kill each other when in contact, but what scientists don't realize is that the portion of the coral killed then becomes dead substrate that both corals attach to. It really looks cool when you have different corals growing on top of eachother like Staghorns (Acropora florida) growing on top of Plate corals like Acropora hyacinthus.

You can have as many different combinations as possible, and the increased complexity increases diversity on your gardened reef since there are different sized refugium available for different sized fish, you will see lots of different species around the targeted area.

As with planting in sandy areas, what I've learnt is that you need to have a considerable sized herbivore population close by (about 10-15 m away, usually if they can see your structure they will come over to it), otherwise there won't be any fish cleaning algae off your structure, and all the racks I have been dealing with in sandy areas usually start and I have to pull them up a little bit every now and then... and after Cyclone Evan, a lot of current went through the area and tossed everything around.

I am currently having problems with damsel fishes (Stegastes sp. possibly nigricans) having a great time in turning my structure (it is a cement one) into an algal farm and killing cultured corals and chasing other fish away at the same time.. I have tried moving them into a different spot but the same thing usually happens again. The reef is a reef patch (near Druadrua island), quite healthy but after about 8 metres there is a lot of sand and hardly any coral. 

Hope this helped a bit and yeah comments and suggestions are welcome.

Comment by Coral Diver on March 18, 2013 at 10:07am

Forgot to add that the fish usually destroy about 30% of cultured stuff, so 70% survives, and I only go over to see the farmed area once a month. The places where I also place the racks are tuned to get the best possible colour from the corals cultured and are species dependent. So some corals need to be grown near these damsel fishes. I have recorded 100% suurvival with some other corals that are grown deeper but I honestly do not want to waste effort with shallow water corals.

Comment by Roberta Davis on March 18, 2013 at 12:14pm

I don't know if you have seen this or not, but the first slide is an interesting formation that we are trying to see if we can modify with PVC pipe.  Check out the anchor system they are using, I think that would work well.  I think before we go crazy on it we may just try a few prototypes.

http://www.foxnews.com/world/2013/02/26/in-tourism-dependent-caribb...

Do you have the problem with those nasty Crown of Thorns blooms? 

 

Comment by Coral Diver on March 27, 2013 at 4:21pm

Well as for corals attaching or settling to plastic or PVC, I haven't seen such a thing, unless you use epoxy putty or super glue (try a few types to see which works well) which is very expansive. But I think you should honestly use cement because its made from corals and corals and other marine life love settling on them.

As for Crown of Thorns, the only places I've seen Crown of Thorns blooming is near Resorts. I use to monitor COTS around South Sea Island for a few years. The site where we used to remove a lot of COTS from was near their underground drainage trench (every septic tank has one) for their septic tank. 

The best way to address COTS is by improving water quality. ie. Find a way to transport solid waste back to the island (including sewage), and as for the liquid waste, try and create an artificial wetland (ponds with mangroves, seaweed, algae that you harvest every now and then).

 

Comment by Roberta Davis on March 27, 2013 at 5:38pm

The corals actually will attach to PVC.  Aquarium enthusiasts use it as part of their coral planting tools.   We just have to use a tie down strap to secure them.  Then anchor the whole contraception.  I am going to try a few prototypes in a couple of weeks and see how they go over a 2 month period before I go gung ho on it. 

Your finds on COTs are interesting, we don't have septic run off on the reef  in front of us.  This area has everyone up on a hill/c;liff about 60 ft above sea level at the lowest point and then the coastal road runs at the bottom between the beach.   When the entire  island gets the bloom is after hurricanes, and that has been true since I think it was Gaviin late 97 ot early 98 .  They come in droves after the big storm surf when the reef is already decimated and just starting to bud.  Once we get it under control we are good until the next hurricane.  I don't know why it happens like that perhaps they got stressed out during the storm and once they emit their reproductory pheromone they are starting the process.  Or perhaps because there is a lack of corals after a storm when they send out their chemical signal that travels for miles to alert other COT's they have discovered a good feeding ground.  It is anybody's guess, but it does happen every single time after the hurrican storm surf.  The fact that a single one can eat 65 sq ft of reef in a year  and you have a few hundred of them and they can go 6 months without food is a little worrisome on anybody's reef garden. 

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