[Coral-List] cold water coral kill

Alan Strong Alan.E.Strong at noaa.gov
Thu Jan 28 15:06:40 EST 2010

I can only wonder how much the corals of the entire region might 
ultimately show an increased tolerance to bleaching & especially disease 
in the coming years because of these colder temperatures.  We know 
extremely cold temperatures in the GBR back in 2004 [Heron Island] saw a 
rapid bounce back following the low SSTs....what about recovery in the 
Gulf of California from cold water bleaching a couple years ago???


Hoegh-Guldburg, O., M. Fine, W. Skirving, R. Johnstone, S. Dove and A.. 
Strong (2005). Coral bleaching following wintry weather. Limnology and 
Oceanography 50(1): 265-271.

On 1/27/2010 3:55 PM, Eugene Shinn wrote:
> Coral listers, Here is the article from todays
> Miami Herald concerning the recent cold water
> episode. Reminds me of the 1969/70 winter chill
> that killed about 80 percent of the Montastrea at
> Hens and Chicken reef and the 1977 (snow in
> Miami) cold water event that killed Acropora at
> Dry Tortugas. It demonstrates why Acropora never
> proliferated in some of the Acropora "critical
> habitat" areas. Gene
> Coral in Florida Keys suffers lethal hit from cold
> Miami Herald, Posted on Wed, Jan. 27, 2010
> 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 1Z(2 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.
> On Tuesday, the Florida Fish and Wildlife
> Conservation Commission reported that record
> numbers of endangered manatees had already
> succumbed to the cold this year -- 77, according
> to a preliminary review. The previous record, 56,
> was set last year. Massive fish kills also have
> been reported across the state. Carcasses of
> snook and tarpon are still floating up from a
> large fish kill across Florida Bay and the
> shallow waters of Everglades National Park.
> 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.
> Coral-bleaching has struck the Keys in the past,
> most recently twice in the 1990s, preceding a
> die-off that claimed 30 percent of the reef
> tract. But those events, along with others that
> have hit reefs around the world, have usually
> been triggered by water hotter than what corals
> typically tolerate.
> Healthy corals depend on a symbiotic relationship
> between polyps, the living tissues that slowly
> build the hard outer skeletons that give species
> distinctive shapes, and algae called
> zooxanthellae that give them their vibrant
> colors. But when ocean temperatures veer from
> their comfort zone too much or too long, the
> coral begin to shed that algae, turning dull or a
> bleached bone-white.
> The effect usually doesn't immediately kill coral
> but can weaken it, slowing growth and leaving
> fragile reefs -- home to millions of fish, crabs
> and other animals -- more vulnerable to diseases,
> pollution and damage from boaters and divers.
> 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 five- to
> six-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 Bleach Watch program, which monitors reefs.
> The dividing line for damage seems to be Hawk
> Channel, which parallels the Keys on the Atlantic
> Ocean side.
> East of the channel, at reefs such as Looe Key,
> one of the top tourist sites, there was only
> light paling on some coral, she said. In Hawk
> Channel itself, there were dead sponges and
> stressed corals but not many outright dead ones.
> West of the channel toward shore, damage was more
> serious. Walter estimated 75 percent coral loss
> at one patch reef, though with poor visibility,
> it was a limited survey. Some nurseries growing
> small staghorn and elkhorn corals for restoration
> programs also may have been hard hit.
> Over the next few weeks, scientists and divers
> from the Florida Keys National Marine Sanctuary,
> National Park Service, Florida Fish&  Wildlife
> Conservation Commission, Mote Marine Laboratory,
> the University of Miami, Nova Southeastern
> University and other organizations will try to
> get a more complete picture of damage with reef
> surveys as far north as Martin County and as far
> south as the Dry Tortugas.
> While they may not be able to save cold-damaged
> corals, Causey said, chronicling what dies and,
> more important
> ``We're going to know so much more about this
> event than any other event in history,'' he said.
> © 2010 Miami Herald Media Company. All Rights Reserved.

****<><  *******<><  *******<><  *******<><  *******
Alan E. Strong, Ph.D.
NOAA Coral Reef Watch, Senior Consultant
...with AJH Environmental Services...
National Oceanic and Atmospheric Administration
NOAA Coral Reef Watch Program
   e-mail: Alan.E.Strong at noaa.gov
URL: coralreefwatch.noaa.gov

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