Rising sea levels may help select coral reefs

PERTH, Australia, Aug. 19 (UPI) -- Though the factors triggering rising seas may be harming the planet's marine species, more ocean water isn't necessarily a bad thing. New research suggests for some coral reef systems it may be beneficial.

For coral, large temperature swings are to be avoided. That's getting harder in a warming world, especially for coral subject to dramatic tidal systems.

As scientists at the University of Western Australia argue in a new paper, published this week in the journal Science Advances, high sea levels may insulate vulnerable corals against tide-triggered temperature spikes.

"Temperature is widely recognized as a key environmental driver of reefs and temperature extremes are known to be one of the key stressors to coral reef communities around the world," Ryan Lowe, a researcher with UWA's Oceans Institute and School of Earth and Environment, said in a news release.

Data detailing how tides influence temperature is limited, but Lowe and his colleagues designed a model to analyze the effects of tides and global temperatures on water temperature. The simulation can predict how tides influence the temperatures in shallow reef systems, and how these systems might be affected by global warming.

The model identified several shallow reef systems subject to tidal temperature swings as large as 50 degrees Fahrenheit. Simulations showed shallow reef systems reach maximum temperatures when low tides align with the midday sun.

"These temperatures are particularly extreme in regions when the tidal range is large when compared to the water depth over a reef, which can cause shallow water to 'pond' within reefs for extended periods of time each day," Lowe explained. "So even a modest rise in sea level could help lower the water temperature of the reef and may also partially reduce reef heat extremes in the world's warming oceans."