Better adapted corals

A team from the School of Biology has secured a €2.1 million European Research Council (ERC) Consolidator Grant to carry out a ground-breaking study into the feasibility of using selective breeding and an innovative mass repopulation method to help corals affected by bleaching.

John Bythell, Professor of Coral Reef Biology,is one of the team leading the study. He said: “During coral bleaching events, it is possible to observe healthy colonies next to bleached colonies, suggesting that some corals are better adapted to higher temperatures. This means that one possible solution could be to selectively breed corals that can withstand higher than normal temperatures and successfully pass this onto offspring.”

The five-year ‘Assisting Coral Reef Survival in the Face of Climate Change’ (CORALASSIST) project is the first long-term, large scale assessment of whether an ability to withstand higher sea temperatures can be passed onto offspring without losing other traits such as growth rate and reproductive success.

If the team are successful, they will then refine a mass transplant technique first developed by Newcastle University so that damaged reefs can be repopulated with sexually produced corals.

Professor Bythell added: “Existing conservation measures such as Marine Protected Areas are an important element in protecting reef systems from local human impacts, but even well-managed reefs can be damaged by increased sea temperatures, which are occurring on regional and global scales.

“This means innovative solutions are needed to help coral species adapt to new environmental conditions. If we can select more tolerant corals and then successfully and cost-effectively transplant them, this would make reef restoration projects much more sustainable in the longer term, pre-adapting the reefs to future climate change impacts.” 

Keystone species

Coral reefs are among the most diverse ecosystems on earth, providing an important habitat for a wide range of species and providing food and livelihoods for hundreds of millions of people in more than 100 countries.

Like trees in a forest, corals are a foundation species creating much of the complex habitat needed to support the remarkable levels of biodiversity found on reefs. But since the 1980s, many species of coral have suffered bleaching as a result of increasing ocean temperatures linked to climate change. 

Although bleaching events are becoming more frequent, ocean temperatures fluctuate between years so bleaching tends to be episodic. Current projects to assist evolution in corals aim to selectively breed corals that can survive these peak temperatures. However, the focus of the research at Newcastle University will be to ensure that greater tolerance to heat does not come at the expense of other traits. The research team hope that by taking a holistic view, they can develop coral strains whose enhanced traits can be inherited, giving stressed reefs a greater chance of survival in the long-term. 

Cost effective reef restoration

The Newcastle team will partner with SECORE International, a non-profit coral reef conservation organisation, to develop techniques for scaling up repopulation and to transfer knowledge to other reef locations. This could include new cost-effective techniques being developed by Dr James Guest, Research Fellow and co-lead on the CORALASSIST programme, to transplant large numbers of corals to degraded reef areas.

Dr Guest said: “Coral reefs face enormous challenges due to local human pressures and global climate change. Assisted evolution is a ground-breaking and novel approach to conservation in certain economically important ecosystems such as forests and coral reefs. These approaches, however, involve certain risks for recipient populations such as resource trade-offs between heat tolerance, growth and reproduction. Furthermore, we don’t know if traits such as heat tolerance are heritable, this is critical if assisted evolution is to have any long term impact on recipient population fitness.

“The potentially high cost and labour involved in management interventions such as assisted evolution, could potentially divert scarce resources away from other conservation measures. It is imperative therefore to demonstrate that these techniques are likely to be successful in sustaining biodiversity and ecosystem goods and services, before they are implemented.”

Learn more about how research led by Newcastle University has already helped to change how the world’s precious coral reefs are protected and restored.