Never mind predictions of catastrophic bleaching from global warming, cold is the culprit of this story. With ocean heat content now shown to be dropping slightly since 2005, there is even greater concern.
Excerpts from Physorg.com: Coral in Florida Keys suffers lethal hit from cold
January 30, 2010 By Curtis Morgan
Bitter cold this month may have wiped out many of the shallow water corals in the Keys.
Scientists have only begun assessments, with dive teams looking for “bleaching” that is a telltale indicator of temperature stress in sensitive corals, but initial reports are bleak. The impact could extend from Key Largo through the Dry Tortugas west of Key West, a vast expanse that covers some of the prettiest and healthiest reefs in North America.
Given the depth and duration of frigid weather, Meaghan Johnson, marine science coordinator for The Nature Conservancy, expected to see losses. But she was stunned by what she saw when diving a patch reef 2.5 miles off Harry Harris Park in Key Largo.
Star and brain corals, large species that can take hundreds of years to grow, were as white and lifeless as bones, frozen to death. There were also dead sea turtles, eels and parrotfish littering the bottom.
“Corals didn’t even have a chance to bleach. They just went straight to dead,” said Johnson, who joined teams of divers last week surveying reefs in the Florida Keys National Marine Sanctuary. “It’s really ecosystem-wide mortality.”
The record chill that gripped South Florida for two weeks has taken a heavy toll on wildlife — particularly marine life.
Many of the Florida Keys’ signature diving destinations such as Carysfort, Molasses and Sombrero reefs _ as well as deeper reefs off Miami-Dade and Broward — are believed to have escaped heavy losses, thanks to warming effects of the Gulf Stream. But shallower reefs took a serious, perhaps unprecedented hit, said Billy Causey, Southeast regional director of national marine sanctuaries for the National Oceanic and Atmospheric Administration.
Cold-water bleaching is unusual, last occurring in 1977, the year it snowed in Miami. It killed hundreds of acres of staghorn and elkhorn corals across the Keys. Neither species has recovered, both becoming the first corals to be federally listed as threatened in 2006.
This big chill, said Causey, shapes up worse.
“They were exposed to temperatures much colder, that went on longer, than what they were exposed to three decades ago,” he said.
Typical winter lows in-shore hover in the mid- to high-60s in the Keys.
At its coldest more than a week ago, a Key Largo reef monitor recorded 52. At Munson Reef, just about a half-mile off the Newfound Harbor Keys near Big Pine Key, it hit 56.
At Munson Reef, said Cory Walter, a biologist for Mote Marine Laboratory in Summerland Key, scientists saw losses similar to what was reported off Key Largo. Dead eels, dead hogfish, dead coral — including big coral head 5- to 6-feet wide, bleached white with only fringes of decaying tissue.
“They were as big, as tall, as me. They were pretty much dead,” said Walter, who coordinates Mote’s BleachWatch program, which monitors reefs.
Read the entire story at physorg.com
h/t to Leif Svalgaard