'Twilight Zone' could help preserve shallow water reefs

February 6, 2019, University of Queensland
Credit: University of Queensland

Corals lurking in deeper, darker waters could one day help to replenish shallow water reefs under threat from ocean warming and bleaching events, according to researchers.

The University of Queensland and the ARC Centre of Excellence for Coral Reef Studies examined corals from the ocean's 'twilight zone' at depths below 30 metres.

Dr. Gal Eyal, the Marie Skłodowska-Curie fellow at UQ's Marine Palaeoecology Lab, said the mesophotic zone was deeper than recreational SCUBA diving limitations.

"Corals in this zone are often overlooked or ignored but occupy at least 50 per cent of unique coral habitats," Dr. Eyal said.

"Light is limited when descending to these depths, so it's a major factor in the livelihood of the ecosystems there.

"We showed that strictly mesophotic coral can grow much faster when it is transplanted to a shallow light environment.

"In the corals experience light limitations, so they allocate their energy accordingly."

Dr. Eyal said the improved performance of the corals collected from 40 to 50m depth and placed in shallow water conditions was promising, but more research was needed to better understand the physiological processes controlling the phenomena.

"This study shows that while there are restrictions in nature currently preventing the persistence of these corals in shallow reefs, the potential is there."

"The 'twilight-zone' needs to be considered an important zone of , instead of the marginal environment it is often viewed as today."

Dr. Eyal said the deep could reveal many more secrets that could help researchers understand coral reefs.

"Coral reefs are diminishing worldwide due to , so we strongly advocate for the protection and conservation of these deeper and unique environments in order to secure a future for reefs."

The research is published in Royal Society Open Science.

Explore further: New research on deep reefs finds 195 species of coral

More information: Gal Eyal et al. Photoacclimation and induction of light-enhanced calcification in the mesophotic coral Euphyllia paradivisa, Royal Society Open Science (2019). DOI: 10.1098/rsos.180527

Related Stories

Scientists find corals in deeper waters under stress too

August 27, 2018

Coral reefs around the world are threatened by warming ocean temperatures, a major driver of coral bleaching. Scientists routinely use sea-surface temperature data collected by satellites to predict the temperature-driven ...

Deep reefs unlikely to save shallow coral reefs

February 15, 2017

Dr Pim Bongaerts, a Research Fellow at The University of Queensland's Global Change Institute (GCI) and ARC Centre of Excellence for Coral Reef Studies, and lead author of the study, said deep reefs share coral species with ...

Recommended for you

Where is the universe hiding its missing mass?

February 15, 2019

Astronomers have spent decades looking for something that sounds like it would be hard to miss: about a third of the "normal" matter in the Universe. New results from NASA's Chandra X-ray Observatory may have helped them ...

What rising seas mean for local economies

February 15, 2019

Impacts from climate change are not always easy to see. But for many local businesses in coastal communities across the United States, the evidence is right outside their doors—or in their parking lots.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.