Implementation of research-based coral restoration practices through coral thermal assay pre-screening and microbiome transplantation to increase visible and invisible biodiversity – Creating a sustainable blueprint for science-led coral restoration
Coral reefs are biodiversity hotspots and economically important for almost a billion people globally. Ongoing seawater warming triggers coral bleaching, i.e. coral whitening due to the loss photosynthetic algal endosymbionts, that ultimately leads to mortality if conditions persist. Coral bleaching is decimating coral cover globally with projections of losing > 90 percent of corals by 2050 if global warming exceeds 2°C above pre-industrial temperature. To counter this alarming trend, reef survival requires an international dedicated effort based on reducing carbon emissions, improving local conditions, and coral protection/restoration.
Despite evidence that research-based approaches can enhance coral restoration outcomes, most restoration efforts lack scientific guidance. Consequently, in many cases the effectiveness of research-informed decision-making on the trajectory of restoration outcomes or how far coral restoration helps to maintain or recover biodiversity, is unknown. Here I propose to assess to what extent phenotypic screening for thermal resilience can improve restoration outcomes employing short-term acute thermal assays for coral selection. Following screening, corals with superior/inferior thermal tolerance are used as source material for restoration and for coral microbiome transplantation (CMT). In parallel, eDNA approaches will be employed as a monitoring tool to assess the ‘invisible’ biodiversity and distribution that is recovered when corals are restored. Additionally, remote underwater videography will assess changes in fish biomass resulting from restoration efforts.
Coral restoration projects face a current backlash as restoration efficacy and long-term success are currently unclear due to the lack of evidence-based investigations. Arguably, restoration outcomes may be significantly improved through science-informed interventions that provide a critical element to rebuild reefs at a local scale, in particular in low-income countries that do not have large geospatial or genetic approaches at their disposal. Gili Asahan, an island in the Lombok Strait, presents an ideal test site for this approach. Here, repeated coral bleaching and illegal fishing have severely damaged the reef, yet local efforts for reef protection are already underway. By developing and implementing evidence-based coral restoration practices conceptualized with methods that are applicable in resource-limited areas, this project will hopefully spur a sustainable, community-driven restoration program, which aims to create a replicable model that can be applied in similar contexts globally, ensuring the long-term survival of coral reefs through localized, science-led interventions.