Coral reefs are home to 25% of the world’s marine species. However, they are in steep decline. Since pre-industrial times, global sea temperatures have risen an estimated 1ºC, and this rise has led to substantial coral loss from widespread bleaching. In 2020, Australia’s Great Barrier Reef suffered a third mass bleaching event in just five years. Similar events damaged two-thirds of the reef in 2016 and 2017.
However, scientists in Australia have found a way to produce coral that is more resistant to temperature-induced bleaching. The team used a bolstering technique to increase the heat tolerance of the coral’s ‘microalgal symbionts’ – tiny algae cells that live inside coral tissue. These algae cells are critical for the coral’s heat tolerance, and by manipulating them, the researchers were able to strengthen their heat tolerance. The team explained that a “direct evolution” technique was employed whereby microalgae were isolated and then gradually exposed to warmer temperatures for four years. This build up in exposure aided their adaptive abilities.
Lead researcher Dr Bueger explained: “Once the microalgae were reintroduced into coral larvae, the newly established coral-algal symbiosis was more heat-tolerant compared to the original one.”
The team found that the heat-tolerant microalgae were also better at photosynthesis and improved the heat response of the coral animal. Although this research is preliminary, it points towards innovative solutions for protecting coral from rising sea temperatures.
further reading…
Coral reefs are home to 25% of the world’s marine species. However, they are in steep decline. Since pre-industrial times, global sea temperatures have risen an estimated 1ºC, and this rise has led to substantial coral loss from widespread bleaching. In 2020, Australia’s Great Barrier Reef suffered a third mass bleaching event in just five years. Similar events damaged two-thirds of the reef in 2016 and 2017.
However, scientists in Australia have found a way to produce coral that is more resistant to temperature-induced bleaching. The team used a bolstering technique to increase the heat tolerance of the coral’s ‘microalgal symbionts’ – tiny algae cells that live inside coral tissue. These algae cells are critical for the coral’s heat tolerance, and by manipulating them, the researchers were able to strengthen their heat tolerance. The team explained that a “direct evolution” technique was employed whereby microalgae were isolated and then gradually exposed to warmer temperatures for four years. This build up in exposure aided their adaptive abilities.
Lead researcher Dr Bueger explained: “Once the microalgae were reintroduced into coral larvae, the newly established coral-algal symbiosis was more heat-tolerant compared to the original one.”
The team found that the heat-tolerant microalgae were also better at photosynthesis and improved the heat response of the coral animal. Although this research is preliminary, it points towards innovative solutions for protecting coral from rising sea temperatures.