Breeding Climate-Proof CoralsReading time: 2 minutes
Researchers at the Australian Institute of Marine Sciences (AIMS) and Hawaii Institute for Marine Biology have begun a five-year project which aims to expose corals to predicted future climate conditions to test whether they have the ability to transfer inheritance of more tolerant traits to their offspring.
The work is taking place at Australia’s National Sea Simulator, a world-class marine research aquarium facility for tropical marine organisms. The facility includes huge tanks with a capacity of 5,000 litres and precise controls on variables such as light, temperature, acidity, salinity, sedimentation and containments, all of which are essential for multi-generational studies on corals. Researchers have already begun the process of growing corals for three generations in tanks with the predicted pH and temperature conditions for 2050 and 2100. The researchers hope to streamline the process of generational adaptation transfer by artificially selecting corals that have been most successful in the new conditions and breed them together to create new hybrids. The benefit of hybrid corals for coping with environmental stressors has been seen previously in the wild; some years ago in the Caribbean staghorn coral fused with elkhorn coral to produce a new species called Acropora prolifera. This hybrid species has been found to be more heat-tolerant and surge-resistant than its predecessors.
The Australian Institute of Marine Science National Sea Simulator (Image credit: AIMS)
The research falls under the field of study known as coral epigenetics which is in it’s infancy compared to other strands of epigenetics. Many organisms employ a non-genetic mechanism of adaptation which allows them to swiftly adapt to environmental changes by, instead of changing the actual genetic code, modifying the context of their genomes and altering when, and to what degree, a gene will be expressed thus improving their physiological capacity to cope with new long-term stresses. The advantageous responses (termed epigenetic mechanisms) are imprinted onto the genome using “molecular tags”, such as DNA methylation and histone modification. This allows the organism to recall these responses if similar conditions reoccur in the future. Previous research on organisms such as mice and plants has shown that these modifications can be passed on to the next generation to provide a “head start” for their offspring. This project hopes to discover whether this extraordinary process can also occur in corals.
Diagram illustrating a simplistic view of DNA methylation (Image credit: Chronic Illness Blog)
The ultimate aim of the project is to create super-resilient corals which could be transplanted onto damaged reefs to restore and maintain natural ecosystem functioning in the face of climate change. However, there are some major concerns for the project with researchers uncertain whether any of the corals could adapt to two degrees of warming. Additionally, the process of coral transplantation comes with the risk of introducing foreign microbial pathogens to the natural ecosystem.
Featured image credit: Meinhardt