Effectiveness of the Three-Step Technique Copy

The methods described in the last few topics are some of the simplest, low-resource intensive, and effective methods of coral restoration available to local or community-based reef managers. Because of the high degree of adaptability of these techniques, locally available materials can be used, and the project scope can be adjusted to fit any budget.

The project can be carried out continuously, and the training of visitors or community members on the methods can help to provide funding and a continuous stream of volunteers and manpower. As a local reef manager, increasing education and awareness of the wider community is essential to address the problems and gain support for necessary projects. Training others in conservation, research, and restoration will ensure that you have enough volunteers and long-term assistance in implementing and maintaining the projects.

Short-term success in rearing and transplanting corals using the three-step system with a nursery stage generally provides a reduction in mortality of coral fragments, increased coral coverage, and increased reef biodiversity (including fish and invertebrates). If the process is carried out following all of the considerations described previously, both short and long-term success can be high, and externalities or unforeseen problems can be minimized.

Our programs are a testament to this fact. In 2020 our program in Thailand, The New Heaven Reef Conservation Program (NHRCP), was included in a study of 4 long-term coral restoration programs. The findings showed that despite being the program with the smallest budget (by several orders of magnitude), ours was the only one with positive results in all 6 parameters assessed, as you can see below.

Hein, Margaux Y., et al. “Coral restoration effectiveness: multiregional snapshots of the long-term responses of coral assemblages to restoration.” Diversity 12.4 (2020): 153.

The NHRCP has been involved in coral restoration since 2007 and is where many of our methodologies were originally developed. We shifted to a genetic-minded and holistic approach in 2011 following the 2010 mass bleaching event. While we have had our share of setbacks, the program is clearly not a failure. But, as you can see, the program in the US Florida Keys and the UVI actually had lower coral health than controls, and we will get to why that may be.

Of course, setbacks will occur when large disturbances happen, and nobody can predict the next big typhoon, bleaching, or tsunami. But setbacks are not failures. We define failure as when a person or group implements a program that takes resources and capital and does not actually cause positive effects for the environment, or worse, harms it.

Failure during restoration projects usually occurs due to lack of planning, lack of long-term maintenance, or lack of understanding or consideration of the 5 basic factors needed for coral growth. If the methods are adhered to, naturally produced coral fragments can be rescued, reared, and used to increase the coral coverage on the reef – there are no negative impacts if done right.

Long-term success in the form of more resilient reefs (with higher population or genetic diversity and increased coral abundance) is more difficult and requires a broader view of the reefs in terms of spatial and temporal scales. One of the leading reasons for long-term failure is a lack of understanding or care about the diversity of the reefs, and in some cases, projects that had high success in the short term actually harmed the environment in the long term.

You can learn more about this concept in this quick video, which we would like you to watch before proceeding.

One of the leading long-term concerns regarding this restoration method is the effect on the overall genetic diversity of hard corals in the area. Coral colonies formed through asexual fragmentation are clones of the parent colony with the same DNA.

In cases where ‘corals of opportunity’ are regularly and routinely collected from the reefs, the genetic diversity of the restoration feedstock can be high but not higher than that of the parent reef. In cases where asexual coral propagation is practiced using donor colonies, the genetic diversity of the feedstock will be very low or nearly monospecific.

On reefs restored using asexual propagation, long-term resilience and adaptability can actually be decreased due to genetic bottlenecking, and success will be very low or temporary, lasting only until the next major bleaching event or disease outbreak. In the next topic, we will discuss the issues that arrive when programs rely on asexual propagation, which currently seems to be the focus of many of mainstream restoration organizations.