Active Reef Restoration

Coral nurseries allow for the rehabilitation of broken or damaged corals

Active coral restoration refers to projects where time, energy, and resources are devoted to directly increasing the coral reef’s health, abundance, or biodiversity. Together these three factors constitute what is referred to as coral reef resilience.

A reef that has a high abundance of corals that are healthy and formed from a diverse range of coral genera and phenotypes is said to be relatively resilient or able to withstand or recover from disturbances.

There are multiple distinct terms used to describe the action of ecosystem managers that are all different and important in their own right. However, for simplicity, we will refer to all the following terms as ‘restoration’ for now

RemediationAn act or process aimed at repairing damage to an ecosystem
MitigationAn act or process to reduce or control damage to an ecosystem
RehabilitationAn act or process aimed to replace the structure, function, or value (social, economic, environmental) in an ecosystem that has been damaged or destroyed.
RestorationAn act or process aimed at returning (or accelerating) the recovery of an ecosystem to its pre-disturbed state.

                Ideally, active restoration is done after passive restoration or simultaneously with regulations and MPA creation. The most common objectives of active restoration are to restore habitat and corals which have been lost or improve reef resilience to mitigate future disturbances.

To restore an ecosystem effectively, the threat must first be reduced or eliminated. But, as we already discussed, that is highly unlikely in the face of climate change and disease outbreaks. In our current situation, restoration to improve resilience must be implemented to reduce the degree of damage and maintain small areas of the reef to serve as ‘biodiversity banks.’

Proactive and Reactive Restoration

This new paradigm shift in thinking, from trying to recreate the past to instead planning for the future, makes our terms ‘active’ and ‘passive’ a bit obsolete.

The word ‘active restoration’ no longer encompassed what managers are doing or moving towards in their techniques and methods. As Hein et al. point out, in the past, restoration was thought of as bringing the ecosystem back to its historical state. However, bringing ecosystems back to their historical state will not be possible in the face of the increased effects of climate change.

Instead, the focus must shift from maintaining historical species to maintaining the “key ecosystem processes, functions, and services through the next few decades of climate change.”

The authors (Hein et al., 2021) propose two new terms as a way to clarify the actions being done and the intent behind them in the context of a rapidly changing planet: ‘Proactive’ and ‘Reactive.’

Proactive restoration would thus refer to any act or initiative aimed at “protecting and enabling recovery.” These proactive measures then go on to support the reactive measures “aimed at repairing ecosystem function and assisting the recovery of a degraded reef system, should it not be able to recover on its own.”

Hein MY, Vardi T, Shaver EC, Pioch S, Boström-Einarsson L, Ahmed M, Grimsditch G and McLeod IM (2021) Perspectives on the Use of Coral Reef Restoration as a Strategy to Support and Improve Reef Ecosystem Services. Front. Mar. Sci. 8:618303. doi: 10.3389/fmars.2021.618303

For simplicity, we will stick with active and passive for this course, but be aware that these terms are changing in today’s climate.

Many methods and techniques of coral restoration are available to the community-based reef manager, many of which are very cheap and easy to construct or maintain. But, the science behind coral conservation and restoration is relatively new, and these techniques are constantly improving.

In the case of community managers, each community or region will find that different techniques or materials are more efficient, and adapting the techniques is essential for local success. It is important to remember that mistakes are bound to be made in any new field but should not be repeated.

Now that you understand what we are trying to accomplish let’s move on to how we will do it. The next lesson covers popular coral restoration methods to review where the field of coral restoration stands today and what improvements are needed for the future.