Crossbreeding could create stronger future for coral reefs
The hybridisation of algae that live in reef corals could increase their rate of development and provide a means for
corals to adapt to global warming, Victoria University of Wellington research has shown.
A study by Shaun Wilkinson, who graduates with a PhD in Ecology and Biodiversity at Victoria’s May graduation
celebrations, explored the potential of crossbreeding between different types of microscopic algae, which are vital to
the coral’s survival.
A partnership, or ‘symbiosis’—between the algae and coral animals—enables corals to survive in nutrient-poor tropical
oceans, and a change of just one or two degrees in temperature can cause a breakdown of this partnership and have
dramatic effects on the reefs. Warming ocean temperatures have already resulted in coral bleaching, death and often the
degradation of entire reefs.
Shaun says natural and human-assisted crossbreeding could allow the algae, and hence the coral, to better survive in
these degraded environments.
“These algae are genetically and physiologically diverse, with some types being more thermally resistant than others,”
says Shaun. “The creation of new genetic material through crossbreeding could create new algal strains that make corals
better able to survive in a warming environment.”
Shaun’s research, recently published in BMC Evolutionary Biology, was conducted during a number of field trips to Lord
Howe Island.
“We looked for potential hybrids by inspecting the genome of single algal cells, and then tested whether these algae
show physiological differences from their ‘pure-bred’ counterparts. We gathered good evidence though further research is
needed to definitively confirm hybridisation,” says Shaun.
“We also measured changes in the abundance of these algae through time, and whether their numbers were correlated with
environmental variables such as temperature and depth.”
Shaun’s research contributes to a global effort to stop the demise of coral reefs, with recent studies suggesting this
loss could occur within the next 100 years.
“There is an emerging field that seeks to selectively breed thermally-resistant corals for the rehabilitation of reefs,”
says Shaun. “Looking at the different ways that corals can evolve and react to temperature changes will be important as
the oceans continue to warm.”
This study was conducted at Victoria University of Wellington under the supervision of Dr Simon Davy and Dr Paul Fisher
from the School of Biological Sciences, and with partial funding from a previous Royal Society of New Zealand Marsden
grant for Dr Davy.
Shaun will graduate with a PhD in Ecology and Biodiversity on Wednesday 13 May.
ends