Coral reef restoration has been with us for some time. If you are looking at examples where coral reef restoration has worked please have a look at the work that has been done by the Coral Guardian in Indonesia:

https://www.coralguardian.org/en/indonesia/

There are many other projects, some with innovative approaches, that create initial 'artificial reef' over an area of coral reef that has been damaged. In Bali, they are using coconut shells to rear corals ((PDF) Coral diversity on artificial reef from coconut shells in northern Bali, Indonesia (researchgate.net), in Lombok they are using Biorock technology (Biorock Reefs Bounce Back After Coral Bleaching: Gili Trawangan Video And Photos By Delphine Robbe - Global Coral Reef Alliance) with success. There are other examples. This being said, it is ESSENTIAL that in all areas where this type of coral reef restoration work is taking place great emphasis has to be placed on maintaining good environmental water quality by managing all anthropogenic activities in a sustainable manner. Maintaining good water quality is very important.

To my knowledge there have not been any large-scale (>km2) coral reef restoration projects using artificial reefs, but many small scale (at 100s of m2) projects have been successful, at least within a short period of time.

I am attaching a list of papers that anyone interested in coral recovery will find useful.

Cheers.

Tom

Borys, you may find the attached paper of some interest.

Cheers,

Tom

Dear Tomas (Tom) Tomascik. Your information is very important to me and my group. I am sure that it will have many views and will increase the level of competence of many interested people. It is very important. I have my own idea. I think that when restoring a reef, it is necessary to first zoning and identify areas where groundwater is very acidic and a polyp cannot form an external skeleton. It is also necessary to identify areas of the reef where groundwater enters the reef structure in small quantities and phosphorus and nitrogen are not enough to form a stable reef biocenosis. I think in these places the artificial restoration of the coral reef will not be productive. Elsewhere progress can be made.

Unfortunately, over time, zoning data ceases to be relevant. The places where groundwater enters sometimes change drastically.

Unfortunately, no one has tested my opinion in practice and has the status of a hypothesis. Thank you for being active in spreading knowledge about the coral reef.

Sincerely, Borуs Kapochkin.

Hi Borys,

Sorry, it looks like ResearchGate did not allow me to attach the reprint of that paper, but here is a direct link to it in the journal:

Article Contrasting coral community structures between natural and a...

Most, if not all, coral restoration projects occur on already well established coral reefs. Majority of the projects have been established to restore corals on physically damaged reefs. The damage is either from natural (e.g., storms) or anthropogenic (e.g., fish blasting) disturbance events. In many of these sites other environmental factors (pollution, groundwater seepage, etc.) are not an issue. Setting up coral restoration projects in an area where the reef destruction occurred due to pollution and deteriorating water quality is more complicated. If those underlying causes of coral reef degradation have been removed coral restoration can be attempted, but if not it would, in my view, be a futile waste of resources. Improved environmental conditions are a key requirement for any future coral reef restoration project considerations.

If someone decides to set up an artificial coral reef project in an area where there is no evidence of any past coral reef development, they would indeed be wise to fist determine whether the environmental conditions, such as those you mentioned, are not present. If there is not history of a reefal development in an area there are probably good environmental reasons why that is so.

Cheers,

Tom

Dear colleagues. I have no understanding of the two episodes from personal experience. 1. In the Red Sea, in the Safaga area, there were no conditions for coral growth in a sandy bay. The water is very acidic. But on an iron rod at a height of 20 cm above the sandy bottom, a perfect coral 15 cm in diameter was formed. Maybe an iron rod is important? 2. I watched a video from South East Asia. In very dirty and murky water, locals grew magnificent corals using a weak electric current. I do not think that anyone is interested in coral reefs in such an ecologically unfavorable area. There is no prospect of fish for fisheries. Perhaps this is a scam? I apologize for such a simple question. Borуs.

Hi Borys,

When you say the water "is very acidic" what exactly do you mean? What is the pH? I have seen very healthy coral reefs in a volcanic setting affected by hydrothermal gas venting in Indonesia. See the attached video from way back.

Dr. Katharina Fabricius, at AIMS in Townsville, has done a lot of work on low pH settings (i.e., ocean acidification) in PNG so have a look at her ResearchGate pages and her papers on the subject:

Katharina Fabricius (researchgate.net)

The fact that the bay is sandy tells me it's a depositional environment and there are probably other environmental factors that are preventing coral reef development.

Not sure what project in Indonesia you are referring to, but the "biorock" reef restoration project in Gili Trawangan in northwest Lombok is very interesting and is clearly not a scam.

Biorock Reef Restoration in Gili Trawangan, North Lombok, Indonesia | (taylorfrancis.com)

Biorock®  reef restoration for s (globalcoral.org)

Cheers,

Tom

Dear Tomas. I asked the last two questions as an amateur in the problem of coral reef restoration. I am not familiar with coral reef restoration projects in Indonesia and cannot discuss them. The problem of the influence of water acidity interests me at a professional level. I specifically studied the negative impact of acidic water on corals and this is the subject of most of our monograph published last year. Look at the photo from the publication of other authors on this issue. https://worldoceanreview.com/en/wor-1/ocean-chemistry/acidification/when-carbonate-formation-loses-equilibrium/. I will quote from the photo "Studies of the coral Oculina patagonia show that organisms with carbonate shells react sensitively to acidification of the water. Picture a shows a coral colony in its normal state. The animals live retracted within their carbonate exoskeleton (yellowish). In acidic water (b) the carbonate skeleton degenerates. The animals take on an elongated polyp form. Their small tentacles, which they use to grab nutrient particles in the water, are clearly visible. Only when the animals are transferred to water with natural pH values do they start to build their protective skeletons again (c)". Sincerely, Borуs.

Relevant and urgent for the opinion above. 1) Environmental tax (green tax) for coral conservation as a response to environmental damage. the concept of implementing an environmental tax on corals and giving tax credits (the polluter pays principle), 2) The cost of an AMDAL/EIA examination. Coral tax as a function of stability, regulatory, budgeting, for coral sustainability in the ecosystem.

Hi Borys,

There are many examples in the literature that clearly demonstrate that ocean acidification will have both negative and positive effect on marine organism. Most calcifying organism will experience negative effects, but some may adapt. One of the most fascinating places that I have worked on is Kakaban anchialine marine lake (i.e., the former lagoon) located on an uplifted atoll in Indonesia. The anchialine lake has a pH ranging from pH7 to pH7.8 yet it supports amazing Halimeda bioherms. Here is a link to a recent short article we published in Galaxea: Article Presence of Alveopora tizardi (Scleractinia: Acroporidae) as...

In addition to the thriving Halimeda 'reefs' the anchialine lake also contains one scleractinian coral species that has adapted to the low pH environment by settling on and colonizing live molluscan shells found in the lake. No research has been done on this species thus far.

I am also attaching a few still photos of the Halimeda stands. This calcifying algae covers most of the lake's shallower areas, as well as mangrove roots. I wish that more research was done in the amazing place.

If you are interested in more details about this unique world have a look at:

Article The ecology of 'Halimeda Lagoon': an anchialine lagoon of a ...

Kind regards,

Tom

Hi Tom.

I learn a lot of useful things from you.

Practice is the criterion of truth.

Amazing pictures. You are living a happy life.

Borуs.