The Great Barrier Reef (GBR) has experienced two years of back-to-back bleaching from elevated sea temperatures. Encouragingly, some coral colonies survive these bleaching events.
Some of their bleaching tolerance is potentially due to the presence of genes involved in thermal tolerance.
New techniques are being explored to help fast-track the distribution of these tolerance genes to other areas of the Great Barrier Reef. These include the intentional relocation of warm-adapted adults or their offspring to new areas (known as assisted gene flow, or AGF) and the ex situ (off site) crossing and deployment of warm-adapted corals with corals of the same species from cooler reefs (known as selective breeding).
This research will test whether the offspring may fare better in a changing climate.
It is an important first step in providing baseline data to assess the effectiveness of assisted gene flow for restoration on coral reefs.
This year during spawning, we will be:
- investigating whether the young of the bleaching survivors from four reefs in the warm waters of the far northern GBR are more stress tolerant than young from the reefs in the cooler central GBR.
- performing proof-of-concept trials to test the efficacy and trade-offs of assisted gene flow in the laboratory.
- assessing the impact of different symbiotic algal communities (Symbiodiniaceae) on thermal tolerance.
- trialling the use of sperm cryopreservation to facilitate breeding between coral colonies from different regions of the Great Barrier Reef (in collaboration with Taronga Zoo).
Assisted gene flow in the National Sea Simulator
The world-class infrastructure at the National Sea Simulator (SeaSim) uniquely allows for the complex, flow-through rearing designs needed to simultaneously assess multiple coral populations collected across over 7° of latitude on the Great Barrier Reef. This includes 108 larval rearing cones, thirty 50L aquariums for chronic heat stress experiments and two 250L baths for acute heat stress.
