Spawning coral. Image courtesy Australian Institute of Marine Science.
There is significant genetic diversity within and among populations of many coral species on the Great Barrier Reef.
Enhanced coral performance interventions are also known as ‘assisted evolution’ as they aim to facilitate the sharing of this genetic diversity; to transfer desirable traits – such as heat tolerance, growth and fecundity – between coral species and populations.
Corals that survive mass-bleaching events, or those that thrive on naturally-warm reefs, are likely to possess heat-resistant genes.
This potential intervention aims to enhance the adaptation of local populations to expected future conditions by moving naturally warm-adapted corals (adults, fragments, spawn, larvae or juveniles) to reefs with less heat-resistant individuals using significant breakthrough larval/polyp-based sexual (coral seeding) or asexual (harvesting coral fragments) aquaculture. This would provide a step change in production rates and cost reductions in using local brood stock to seed reefs.
These methods seek to vastly reduce production durations (from months/years to hours/days) and deployment success (via advanced active deployment devices) to facilitate much larger deployment quantities at an affordable cost.
The young corals, attached to a small device or in small fragments, would be deployed from the surface using automated systems on barges and small vessels, to seed reefs.
It would require measures to ensure the introduced corals did not harm the local population.
This captured coral stock may receive additional treatments such as:
The aim is to increase the number of enhanced corals recruiting into reef populations.