Choosing a suitable restoration site is critical to the success of any coral transplanting efforts. If a reef area is covered in fleshy seaweeds, then it is unsuitable habitat for corals to naturally settle and grow as well for receiving coral transplants.
Protecting key herbivores, fish like surgeonfish and parrotfish that feed on seaweeds and algae, can help ensure that reef areas remain conducive for coral growth. For example, as can be seen in our video attached below, healthy populations of the orange-spine and blue-spine surgeonfish are critical for preventing brown seaweeds from overgrowing the reef. Brown seaweeds take over substrates where corals would otherwise grow in areas where these key herbivorous fish have been overharvested.
Reef areas that are well-grazed where seaweeds are not overgrowing hard substrate are suitable for transplanting corals. Even substrate that sometimes gets covered with shifting shallow sand and thus may be unsuitable for corals to naturally settle and grow on can be suitable for transplanting coral colonies that are large enough not to get buried completely in shifting sediments. These well-grazed but ‘recruitment-limited’ substrates are common target areas for our coral restoration efforts as the addition of corals to these areas helps attract coral larvae that can colonize and grow on surrounding, more suitable hard substrate. Strategies like this that aim to create positive ecosystem feedback loops help lead to the overall success of the restoration effort.