Site level data collection is important to document how population enhancement efforts are affecting the ecological health of a reef site. In addition to assessing and tracking the success of individual outplanted colonies, it is important to know whether outplanted corals are positively affecting other organisms in the site and promoting better ecological functioning and processes. Thus, it is suggested that monitoring of a restoration site be conducted before and after outplanting occurs, so that any changes in the site can be attributed to the specific intervention of coral outplanting.
Another reason to monitor larger reef areas is because current methods for monitoring individual corals long-term can potentially give inaccurate information, particularly for branching corals (e.g., Acropora spp.). For instance, recent research shows that after ~2 years, outplanted branching corals become so large that they fragment or become dislodged – a natural process for wild and restored colonies. ref Individual colony tracking methods may therefore count a dislodged or fragmented coral as dead or missing, when it may have actually given rise to many more colonies located elsewhere in the reef site. Thus, long-term data of individual outplants may show lower success than is really present at the site.
To assess site-wide effects of population enhancement, monitoring areas must be increased to include the entire footprint of the area where corals will be outplanted. The size of the survey area will vary depending on the species outplanted. Mounding corals do not tend to fragment and propagate sites through asexual fragmentation as frequently as branching corals, so survey areas will be smaller. Current site surveys for A. cervicornis include up to 7 m surrounding and including the outplant area. This area was chosen based on typical visibility for the region (southeast Florida), local knowledge about movement of this species, time it takes to survey the area, and surrounding habitat availability. The purpose of these particular surveys is to document site propagation by outplanted A. cervicornis, so data collected includes numbers of colonies and fragment counts for specific size classes. Many other site characteristics are valuable for documenting the success of a population enhancement project, such as:
- Coral cover and coral species abundance
- General benthic species composition (including corals, soft corals, fire corals, sponges, algae, and other major space occupiers)
- Abundance of coral recruits or juvenile corals
- Health of reef-building corals (disease, algal overgrowth)
- Fish and invertebrate species diversity and abundance
- Abundance of key macro-invertebrate species, such as Diadema urchins
- After outplanting, counting the number of corals of the species that has been restored may better capture the abundance of this species than individual tracking (particularly if tracking branching corals)
There are several large-area survey methods for obtaining this data, including newer technologies such as photomosaics, swimming with GPS to gather waypoints of corals, and more traditional survey techniques using quadrats and transects.
- Underwater Landscape Mosaics for Coral Reef Mapping and Monitoring, University of Miami
- Atlantic and Gulf Rapid Reef Assessment (AGRRA)
- Global Coral Reef Monitoring Network (GCRMN)
- Florida Reef Resilience Program