Coral Polyps

“Good coral parenting” for reef recovery found, according to reports in ScienceDaily 16 September 2019 and Scientific Reports 16 September 2019, doi: 10.1038/s41598-019-50045-y.

Corals live in a symbiotic relationship with algae – single celled plants that provide the coral with a lot of nutrients, as well as giving the corals their colour. When the corals are stressed by a change in the conditions, the algae may leave the coral leaving it uncoloured or ‘bleached’.

It has been discovered that the coral does not die straight away, as algae that are more suited to the new conditions can move in and re-establish a symbiotic relationship. This process is known as coral shuffling and enables coral reefs to adapt to changing conditions and recover after natural disasters. Scientists studying corals on the Great Barrier Reef in Australia have found that corals can also pass on symbiotic algae to their offspring.

Scientists from University of Southern California, James Cook University, Australian and the Australian Institute of Marine Sciences studied a common type of the coral on the reef named Montipora digitate, over two spawning seasons, 2015 and 2016. In 2016 there was a major bleaching event. They found the number and type of symbiotic algae were different from one year to the next, which is consistent with previous studies of algal shuffling.

They also found the shuffled algae in the egg cells released by the coral in the second spawning. The researchers wrote: “to our knowledge, this is the first evidence that shuffled Symbiodiniaceae communities (at both the inter- and intra- genera level) can be inherited by offspring and supports the hypothesis that shuffling in microbial communities may serve as a mechanism of rapid coral acclimation to changing environmental conditions.” (Symbiodiniaceae are the symbiotic algae)


Editorial Comment: This study confirms what people who live and work on the reef have known for a long time – coral bleaching does not always end in the death of corals, and reefs can survive and recover from both short term-term and long-term changes in conditions. The shuffling of algae is an example of true adaptation, i.e. the built-in ability to cope with changed environmental conditions. This new study of intergenerational passing on of symbiotic algae confirms that coral reefs are resilient living communities. Coral bleaching is a natural phenomenon that occurs after natural events such as cyclones, storm surges and changes in warm and cold ocean currents, as well as from man-made damage and pollution. While there is no excuse for deliberately damaging and polluting the reef, there is also no reason to use changes in coral reefs to intimidate people about climate change.

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Evidence News vol. 19, No. 15
25 September 2019
Creation Research Australia