New findings from the Museum of Tropical Queensland have found that corals found in deeper waters could help resurrect our dying, shallow reef.
The recent bleaching events across the Great Barrier Reef caused by unusually high water temperatures is the greatest threat to shallow corals. Dr Paul Muir, MTQ’s Coral Collection Manager explains:
“When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white,” Dr Muir said.
“To date, limited understanding of the effects of coral bleaching in deeper waters and within individual coral species has impeded global management of its devastating impacts.”
Following the extreme bleaching in the Maldives last year, Dr Muir, together with a team from Australia, New Zealand and the Maldives analysed 192 different coral species living in depths of three to 30 metres. They examined each coral individually and how it was affected by the bleaching events.
“We found great variation in the effects of bleaching between species, and overwhelming evidence that coral bleaching reduces as water depth increases,” Dr Muir said.
Dr Muir believes that deep corals hold the key to “minimising species extinctions” as they are less susceptible to bleaching. He explains that the deep-sea corals could provide coral larvae to assist in the reseeding of bleached shallow sea coral.
“In the Maldives we calculated the risk of extinction from bleaching for each of the coral species, finding several at high risk and three that already appear to be extinct in the area.”
Dr Muir was pleased to find that some species of coral appeared to have adapted to the increase of water temperature.
“We discovered some highly resistant corals within three species normally considered very vulnerable to bleaching which suggests a small number of species may be able to adapt to rising sea temperatures.”
The researchers wish to do similar research at the Great Barrier Reef to see whether reseeding damaged coral with deep-sea reef larvae would help struggling, bleached shallow reef adapt to rising sea temperature.
Lead Image: This panoramic image reveals coral bleaching at Lizard Island on the Great Barrier Reef in March 2016. PHOTOGRAPH BY XL CATLIN SEAVIEW SURVEY