Corals May Hold Key To Own Survival In Their Genes


A coalition of Australian and American scientists have discovered what could be a crucial weapon in the fight to save the Great Barrier Reef, with new research indicating that the key to combatting bleaching could be in coral genetics.

American and Australian researchers cross-bred corals of the same species from two sites 540 kilometres apart, where there is a natural two degree difference in temperatures, and found that corals living in warmer waters on the north of the Great Barrier Reef pass on a higher temperature tolerance to their offspring.

The heat-resistant northern corals had 10 times the normal survival rate when exposed to higher temperatures, which is critical because the Great Barrier Reef is already suffering badly as the temperature of oceans warms across the board.

Over the last three decades the reef has lost around half of its coral cover and government scientists consider its condition to be ‘poor and deteriorating’.

One of the leading causes of the reef’s demise has been coral bleaching which occurs when temperatures extend above their usual range and corals expel the algae that lives in them. The algae provides not only their colour, but their main source of food.

Credit: Line K Bay, AIMS

Despite recognising climate change impacts as the greatest long-term threat to coral reefs, a recent Federal government rescue plan for the Great Barrier Reef largely ignored the obvious questions around how to counter the effects of phenomena like rising ocean temperatures.

The discovery that corals have evolved their own adaptation to deal with warmer waters suggests those with heat-resistant genes would naturally colonise the cooler reefs off Queensland’s coast as global warming forces the overall sea temperature up.

However, the scientists have also suggested that, in order to help absorb some of the shock of warming global waters, researchers should now focus on how the discovery could be applied proactively.

“Averting coral extinction can begin with something as simple as exchange of coral immigrants across latitudes, which will happen naturally through larval dispersal but can be jump-started by humans moving adult corals,” said Mikhail Matz, a professor of integrative biology at the University of Texas at Austin.

The researchers also suggested that heat-tolerant coral communities could be protected so that they are able to naturally repopulate other reefs, but noted that further research was needed before governments can start picking ‘winners and losers’ in a changing climate.

It is unlikely that the genetic adaptation researchers have discovered would keep pace with the predicted rise in ocean temperatures but artificially accelerating the rate of the adapted corals’ spread could buy crucial time while further research is undertaken.

The researchers behind the findings, outlined in the journal ‘Science’ , believe that heat-resistant coral larvae had altered genes working in the mitochondria, an organelle inherited only from mother corals, and flagged this as an future direction for research.

In order to salvage the Great Barrier Reef such research will have to move quickly, and with the Federal government on a fresh probation period after narrowly avoiding a World Heritage Committee ‘in danger’ listing recently the Abbott government may need to update its plans to incorporate developing research.

In a positive sign the Federal Environment Minister announced that a new panel of 16 experts who will help it hone and implement its ‘Reef 2050 Sustainability Plan’ will include climate scientists as part of the advice process designed to “ensure the government is using its resources to the best possible effect”.

Increasingly, the government’s resources will need to expand into tackling questions of how to protect the reef in a climate-changed world, and research like this study will prove crucial.

The government will have to justify its conservation efforts to the United Nations World Heritage Committee again in June next year.

Launched in 2004, New Matilda is one of Australia's oldest online independent publications. It's focus is on investigative journalism and analysis, with occasional smart arsery thrown in for reasons of sanity. New Matilda is owned and edited by Walkley Award and Human Rights Award winning journalist Chris Graham.