The immense biological, sociological and economic value of the Great Barrier Reef (GBR) is being rapidly degraded by anthropogenic stressors. Reef restoration approaches are being investigated to ensure the persistence of the Great Barrier Reef while these stressors - most critically climate change - are addressed.
During the 2019 spawning period, we will examine the efficacy of two components of novel coral reef restoration. These hybridisation and parentage experiments will generate critical knowledge required to develop the most efficient methods for maximising the production of genetically diverse coral larvae for large-scale larval restoration initiatives.
Hybridisation
Interspecific hybridisation has the potential to generate resilient corals that could be used as stock in reef restoration initiatives to equip reefs for a changing climate. The performance of interspecific hybrid corals has been tested under predicted future ocean conditions in the laboratory, showing that coral hybrids can be more resilient to elevated temperatures and pCO2 levels than their purebred parents.
During the 2019 spawning period we will mix the eggs and sperm of different coral colonies to generate new hybrid and purebred corals. We will then outplant these corals onto the reef and monitor and compare their performance over time.
This experiment will assess the performance of interspecific hybrids in their natural environment. It will hopefully provide us with critical insights as to whether interspecific hybrids can be used as a viable tool to guard reefs against climate change.
Testing for equal parentage
A recent change in reef restoration approaches is a shift away from using adult coral fragments and towards the use of sexually produced coral larvae to reseed reefs.
The most common approach for producing large numbers of coral larvae is to mix the eggs and sperm from multiple colonies simultaneously. It is generally assumed that all parents in such a mix contribute equally to the offspring, but this has never been validated.
During the 2019 spawning period, we will conduct a series of parentage experiments to test this assumption. We will mix the eggs and sperm of different colonies together in a series of crosses. We will then use genetic markers to identify the parents of the larvae produced through each of the crosses and use this information to assess whether each of the parental colonies contribute to the larval crosses in equal proportions.
