Proliferation of growth of sea weeds on corals may not be looked upon with concern.The reasons being: Along with molluscs,corals are the only other material where the diploid stage of marine weeds can harbor them selves when the abiotic factors go away from the optimum levels. They are the repository of sea weeds & can be drawn upon when needed by nature. Sea weeds need hard substratum for them to have have a firm foot hold & therefore corals are one of the natural substratum. Again,by having corals by any means would again increase weeds,as they are one of the prime substratum for settling spores.

Taking a contrarian view, increasing the predators of weeds, could attract predators of these animals leading to predation mortality, as managing natural ecosystems are fraught with imponderables.

An alternative could be:harvest the excess weeds periodically & make liquid sea weeds fertilizer, which is used as tonic fertilizer & is in high demand in all agricultural fields.

Sorry, but I think  this answer is not relevant to my question.  Maybe it was  missinterpreted.

Best wishes, Pedro

Coral transplantación should be implemented in isolated reefs where coral cover was formerly remarkable but declined in recent times to very low levels or formerly dominant species are now absent in the coral community. However, transplantación will  be successfull only if the conditions for coral growth in the area have been re-established. In reef areas ahah

Dear Juan Manuel. I fully agree with your statement.

The end of your answer seems to be cut..

Best!

Dear Pedro,

I think transplantation is viable if you have a source of corals that are threatened by development in another area. Transplantation can mitigate environmental impacts by harvesting corals that are at risk for loss. But not all species are suitable for transplantation unless depth, light regime, water motion etc. are comparable between the donor  and recipient sites. If the transplanted corals are relatively older and larger then they are less likely  to be affected by competitive reef algae and may have a good chance of survival.

I would not be supportive of harvesting corals from a "healthy" reef for transplantation. "Healthy"  reefs need to to keep what they have, as many factors seem to keep stressing these reefs. You can't risk taking  corals from a " healthy" reef and place them in a compromised habitat when survival rates may be low. In the end, only "healthy" reefs will provide the sources of planulae that will re-populate degraded reefs.

I certainly agree that you must understand if the current conditions at the recipient site have  improved such that the historic factors that had caused the loss of corals are no longer operating.

I have attached a copy of Bill Precht's paper on reef restoration.

Best regards,

Robbie

If the cause of the coral die-off was disease, transplantation of prescreened resistant strains would be prudent. Otherwise, promoting recovery of herbivores is an excellent protocol to encourage recruitment.

I think we must understand first what is exactly going wrong with our coral reefs and why are there seaweeds on excess. Otherwise, all the efforts and money will be lost. We need to reach some favourable conditions for corals (i.e. herbivores, low levels of nutrients, clear waters, etc.) for being succesfull, because seaweeds can colonize more quickly than corals.

True

I totally agree with Beatriz

I agree, herbivore recovery and coral transplantation probably need to be implemented together. Without recognising & addressing the underlying problem (eg over fishing, declining water quality and disease) the reefs will never truly recover. Solutions should be sustainable and promote long-term recovery and health. Coral transplantation can help re-initiate/seed a reef, but ideally it should not be required in the long-term at the same location. 

Excellent answers put together!  Jennie nicely complemented the  former criteria.  It is just an issue submitted to much discussion nowadays.

With the experience from our Gulf of Mannar, India, I can say that coral transplantation is much important than promoting herbivores or sea urchins. We have succeeded in transplantation with more than 90% survival and the transplanted colonies are now sexually mature and participate in the annual spawning. The area which we transplanted 10 years ago has (more or less) developed in to a natural reef with the help of both sexual and asexual reproduction. By the way, recovering herbivores and sea urchins can be an added activity to check the algal cover. But, certainly (at least in our area) transplantation with the native species is the best option to increase the live coral cover.

Coral transplantation could not suitable for all the environment and it depends on these  physio, bio and chemical parameters. Transplanted corals should tolerate the new environment than only we can say whether is growing fast or not. Seaweeds are only found to attach with the dead corals but as you concerned some species only responsible for the limiting factors particularly coralline algaes which forms a mate over the surface of live and dead corals. Remaining species may recover herbivore population particularly Sargassum species.

Interesting answer that from K Diraviya Raj. It suugests that environmental conditions and threats for coral recovery are different in Manaar compared with the Wider Caribbean..

Very interesting answer. I ask K Diraviya Raj if Gulf of Mannar coral reefs are covered with brown or green macroalgae. Please, do you have any paper about this work you could share with us?

Yes it really is different Pedro!!! We are experiencing recovery after decades of declining, main culprit being the coral mining!! however, new threats like bio-invasion by Kappaphycus and coral diseases are posing threat!!

Hi Beatriz, I have a paper regarding macro algal cover, it was published in 2006 and has very little information!! I dont have it as pdf, give me your email id, i ll scan and send you!! Impact of the red alga Kappaphycus alvarezii on Gulf of Mannar corals has been published recently by many, I can send them too!!!

Coral transplantation is often like 'mopping the floor with an open tap' and resources may be better spent in prevention of runoff, nutrient input, global warming, acidification of the ocean, etc. However, one may consider to transplant (save) corals in cases they are under treat of local extinction. If possible coral should be transplanted to locations with conditions similar to those were these species have been known in the past. However, corals will only serve as founder population when environmental conditions are (close to) optimal. K Diraviya Raj makes me curious as well. Is it possible to develop a natural reef in only 10 years? Did a coral reef exist at this location before?

As to crustose coralline algae (cca), in the Caribbean, I found that scleractinian corals are overgrown by cca when the corals are in bad condition. Some coral species even prefer to settle on cca.

Hi Godfried, Natural corals in the sense, they have overgrown the substrate to the point we can not see the concrete frame now, and natural fragmentation from these transplanted colonies have made new colonization near the restoration site and they are sexually mature as we have recorded coral spawning and gametogenic cycle on these transplanted corals! It was only a dead coral bed 10 years ago!!! Transplantation was done with the native species and environmental parables were conducive apart from annual summer bleaching!!! 

These corals maybe belong to oportunistic fast growing and prolific species, I guess.

Is the water relativery productive and thus, probably favouring heterotrophy and fater growth in corals?

Yeah, they are fast growing corals, mostly Acroporans! and yes, water is relatively productive supporting faster growth, growth rate was around 12 cm/year!!! 

Corals always can provide good fisheries. It has also have the capacity to change the chemistry of the sea water. By providing good or hard substratum may facilitate the regrowth of all fouling organisms including corals naturally if it is alive near by areas. The environmental resilience is most important for better growth of these marine organisms. Corals are good shelters for the young ones of fishes. Like mangroves, corals support more marine biodiversity.