Coral reproduction disrupted by increasing storm damage

ScienceDaily (Aug. 4, 2009) — As global warming whips up more powerful and frequent hurricanes and storms, the world’s coral reefs face increased disruption to their ability to breed and recover from damage.

That’s one of the findings from a new scientific study of the fate of corals in the wake of large climate-driven bleaching and storm events. “We have found clear evidence that coral recruitment – the regrowth of young corals – drops sharply in the wake of a major bleaching event or a hurricane,” says lead author Dr Jennie Mallela of the ARC Centre of Excellence for Coral Reef Studies and Australian National University. Using the island of Tobago in the Caribbean as their laboratory she and colleague Professor  James Crabbe of the University of Bedfordshire, UK, backtracked to 1980 to see what had happened to the corals in the wake of nine hurricanes, tropical storms and bleaching events. “In every case there was a sharp drop in coral recruitment following the event – often by as much as two thirds to three quarters. Not only were fewer new coral colonies formed, but also far fewer of the major reef building coral species recruited successfully.” … “Climate researchers are seeing increasing evidence for a direct relationship between global warming and rising hurricane intensity as well as frequency,” Jennie explains. “Global warming produces significant increases in the frequency of high sea surface temperatures (SSTs), and hurricane winds are strengthened by warm surface waters.” The high temperatures cause bleaching, while the storms inflict physical destruction on the corals as well as eroding the rocky platforms they need to grow on, or burying them in sand. “Maintaining coral reef populations in the face of large-scale degradation depends critically on recruitment – the ability of the corals to breed successfully and settle on the reef to form new colonies. Our research suggests this process is severely disrupted after one of these major events.” …

Coral Reefs Face Increasing Difficulties Recovering From Storm Damage