|Coral populations have genetic potential to adapt to warming oceans, according to new research by Southern Cross University.|
|‘Our previous work revealed that corals in an extreme environment have an exceptionally high heat tolerance, in part due to genetic adaptation of the coral animal,’ said Dr Emily Howells, a Senior Research Fellow at the National Marine Science Centre at Southern Cross University.
‘In this study we wanted to test whether we could transfer these beneficial genetic variants to a comparatively heat sensitive coral population living in milder oceanic conditions.’
The study led by Dr Howells and also involving Southern Cross University lecturer Dr David Abrego was an international collaboration between New York University, Oregon State University, King Abdullah University of Science and Technology, Zayed University, CSIRO, and the University of Wollongong.
The researchers cross-bred corals from the thermally extreme Persian Gulf with those of the same species from the milder Indian Ocean and measured the performance of many families of their offspring.
The team found that heat tolerance increased by up to 84 per cent when Indian Ocean mothers were bred with Persian Gulf fathers and was, on average, equivalent to the heat tolerance of offspring with both parents from the Persian Gulf.
‘This was an impressive result, because while we were expecting to see some enhancement of heat tolerance, the signal was much stronger than we anticipated from the genetic contribution of the fathers alone as maternal effects also contribute to offspring tolerance,’ Dr Howells said.
Genome-wide sequencing of the coral families confirmed these findings by revealing that genetic variants positively associated with heat survival were predominantly inherited from Persian Gulf parents.
The researchers also deployed the offspring to the Indian Ocean site and found that cross-bred corals with Persian Gulf fathers survive equally as well as native Indian Ocean purebred corals, but both had higher survival than non-native Persian Gulf purebred corals.
These results demonstrate that corals can be selectively bred for enhanced heat tolerance using corals from populations in extreme or warmer environments which have a higher proportion of heat-tolerant genetic variants due to local adaptation.