What’s killing corals?
What’s killing corals?
Daily grind shapes coral death
Following decades of study in which scientists tended to focus on extreme and rare causes of coral death, a new study instead looked at the effects of everyday currents, waves and wind. The findings suggest that these subtle and predictable reef processes dwarfs mortality caused by more dramatic events.
The research is part of an ongoing collaborative project at Lizard Island between Josh Madin , Andrew Baird, Sean Connolly and Maria Dornelas, and involved painstakingly tracking hundreds of individual coral colonies every year since 2008.
Josh Madin (who lead this paper) explains
“We found that a coral’s physical strength is really important for surviving the rigours of living on shallow-water reefs. Strong currents and large waves occur quite frequently on the reef, not just during cyclones, and if you think about the enormous area of reef out there, death caused by water motion during the typical summer storms or other periods of strong winds and high waves, which occur on a regular basis, far outweighs death caused by very rare extreme events, like cyclones.”
The study’s key finding is that corals with similar shapes tend to have similar chances of dying as they grow larger. These results greatly simplify ecological models because we can make predictions based on a few simple and easily measured features of corals rather than have to get to know each species intimately.
Sean Connolly adds “Targeted studies that track changes in the vital rates – birth, growth, and mortality – in corals are vitally important for anticipating how they will respond in the future to threats like local-scale pollution and large-scale climate change.”