Hi folks - Misha Matz here.
I am extremely concerned about Caribbean reefs, particularly the region-wide recruitment failure of the main reef-builders, Acropora spp and Orbicella spp, since as early as in 1980’s (see these two papers: https://www.ncbi.nlm.nih.gov/pubmed/25266950 ; https://www.ncbi.nlm.nih.gov/pubmed/27029403). This is a region-wide problem so it is unlikely to be just the natural variation in recruitment rates. Something changed in the mid-20th century and babies of those corals just stopped coming back. Note: other coral species are doing just fine, for example Montastrea, Siderastrea, or Pseudodiploria - lots of young babies of these species everywhere - but they cannot ecologically replace Acropora and Orbicella.<br>
My point is, just planting a lot of fragments these species out there, irrespectively how many or how densely, is not going to accomplish much unless the restored populations become self-sustaining through larval recruitment. I believe solving this recruitment crisis (which, I believe, is the main cause of region-wide decline of Caribbean reefs) requires much more radical and innovative measures than just large-scale coral planting.
I would like to propose a separate competition to solve this problem: How abut a competition to solve the “Caribbean recruitment failure crisis”?