[Coral-List] cold water coral kill
wnuckols at erols.com
Thu Jan 28 18:51:25 EST 2010
Anyone associating the cold with increased climate variability as a part of
climate change, or are people just calling this a weather (as opposed to
From: coral-list-bounces at coral.aoml.noaa.gov
[mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Eugene Shinn
Sent: Wednesday, January 27, 2010 3:56 PM
To: coral-list at coral.aoml.noaa.gov
Subject: [Coral-List] cold water coral kill
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
BY CURTIS MORGAN
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 1Ž2 miles off Harry Harris Park in
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
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
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
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
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
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,
``We're going to know so much more about this
event than any other event in history,'' he said.
C 2010 Miami Herald Media Company. All Rights Reserved.
No Rocks, No Water, No Ecosystem (EAS)
E. A. Shinn, Courtesy Professor
University of South Florida
Marine Science Center (room 204)
140 Seventh Avenue South
St. Petersburg, FL 33701
<eshinn at marine.usf.edu>
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