I know a lot about the selective breeding of purebred cats! I never thought that I would read about the selective breeding of coal reefs but it’s become necessary as a stopgap measure to try and allow coral reefs to survive the rising temperatures in the oceans due to global warming for a wile. And during this stopgap measure it is hoped that the world at large will do all they can to curb global warming, which, at this point in time, does not look that hopeful.
The scientists took a small piece of 150 wild colonies of coral specifically the Acropora digiifera species, a common reef-building coral found in shallow waters across the Indo Pacific. These small pieces of the colonies were transplanted to a tank where the researchers identified those that appeared to be best adapted to deal with warmer conditions.
These selected pieces of coral were then transferred to an aquarium just before they were set to breed to ensure that they interbred.
This involves a vast number of polyps synchronising activity to release eggs and sperm at night a few nights after a full moon in March or April. It takes the offspring 3 to 4 years to reach sexual maturity.
The research was carried out in the Palau Archipelago in the western Pacific Ocean. It is the first to show that coral can be selectively bred and the first to show that they can be selectively bred to specifically withstand warmer temperatures without bleaching.
You may have read about bleached corals. This happens when, due to rising temperatures and worsening water quality, the creatures that make up a single coral (polyps) expel the colourful algae that live in their tissues and which provides them with food. Without colour the coral reef becomes bleached white.
The researchers stress that the selective breeding of corals to withstand high temperatures must be considered to be a stopgap measure to give time to deal with global warming properly.
But the research suggests that it is possible to improve tolerance to short intense heat exposure during which temperatures might spike by 3.5°C for 10 days. Or they can tolerate an increase in temperature of 2.5°C for a month.
The selective breeding does not result in the coral becoming resistant to long heat exposure.
Dr. Adriana Humanes of Newcastle University said: “Considerable work remains before selective breeding can be successfully implemented. A deeper understanding is needed to determine which traits to prioritise.”
The Times newspaper tells me that more than 50% of the world’s coal reef areas have experienced levels of heat stress in the year to April 2024 which would cause bleaching. This information comes from the US National Oceanic and Atmospheric Administration.
This area of bleached coral reef is growing rapidly by around 1% per week. Corals can survive bleaching if it’s not too severe or too prolonged. But if they survive they grow more slowly for several years and they have weaker reproduction.
My thanks to The Times newspaper for this report.
Comment: there is one further comment I’d like to make for what it’s worth. It is all very well to try and create creatures which can deal with global warming but this method of proceeding can demotivate the world’s leaders to do something really tangible and concrete to curb climate change. There would already appear to be a lack of commitment to curbing it. Research which improves tolerance of global warming can, as mentioned, further demotivate.
More: Most sharks living on coral reefs are facing extinction
