Dr. Jeff Masters' WunderBlog

Globe's coral reefs take second worst beating on record during 2010

Posted by: Dr. Jeff Masters, 04:50 PM GMT del 07 Gennaio 2011

Record warm ocean temperatures across much of Earth's tropical oceans during the summer of 2010 created the second worst year globally for coral-killing bleaching episodes. The warm waters, fueled in part by the El Niño phenomena, caused the most coral bleaching since 1998, when 16 percent of the world's reefs were killed off. "Clearly, we are on track for this to be the second worst (bleaching) on record," NOAA coral expert Mark Eakin in an interview last month. "All we're waiting on now is the body count." The summer 2010 bleaching episodes were worst in Southeast Asia, where El Niño warming of the tropical ocean waters during the first half of the year was significant. In Indonesia's Aceh province, 80% of the bleached corals died, and Malaysia closed several popular dive sites after nearly all the coral were damaged by bleaching. However, in the Caribbean's Virgin Islands, coral bleaching was not as severe as experienced in 2005, according to National Park Service fisheries biologist Jeff Miller. I'll discuss the reasons for this in a future blog post. In other portions of the Caribbean, such as Venezuela and Panama, coral bleaching was worse than that experienced in 2005.

Figure 1. An example of coral bleaching that occurred during the record-strength 1997-1998 El Niño event. Image credit: Craig Quirolo, Reef Relief/Marine Photobank, in Climate, Carbon and Coral Reefs

What is coral bleaching?
Coral bleaching is a whitening of the corals that occurs when stresses such as high water temperatures, increased water acidity, or pollution disturbs the symbiotic relationship between the corals and the algae that live inside them. Bleaching episodes occur when ocean temperatures rise above 85 - 87°F (29.5 - 30.5°C.) Peak warming events took place in the western Indian Ocean and north-western Pacific in 1997/98, in the north of Australia and central Pacific during 2003/04, and in the Caribbean in 2005. About half of the reefs affected by bleaching in these episodes have recovered, and one recent study cautions that non-lethal bleaching episodes and subsequent recovery of corals is often under-reported.

Australia's Great Barrier Reef at risk
With summer now in full swing in the Southern Hemisphere, coral bleaching concern now shifts to Australia's Great Barrier Reef. Ocean temperatures along the reef are currently up to 1°C above average, due, in part, to the current moderate to strong La Niña event. NOAA's Coral Reef Watch has issued its highest level of coral bleaching alert for the northern 2/3 of the Great Barrier Reef, since the La Niña event is predicted to persist into at least April. Also of concern is the tremendous run-off occurring in the wake of the record flooding that has affected the neighboring Australian province of Queensland. While the floods have now peaked and the rivers of Queensland are now falling, the $5 billion disaster dumped a large amount of sediments, pollutants, fertilizers, and pesticides into the southern portion of the Great Barrier Reef, and this will act to increase the stress on the corals. However, the floods may end up indirectly benefiting some portions of the Great Barrier Reef. The cloud cover and strong winds that accompanied the flooding rain storms also acted to cool the waters along the reef. According to an analysis I did of the UK Met Office Hadley Centre global ocean temperature data, sea surface temperatures along the southern portion of the reef, between 15°S and 20°S latitude, were the warmest ever for September, 1.27°C above average. These waters cooled significantly, relative to average, during October and November, and were just 0.12°C warmer than average during November. Cooler waters will mean less potential for coral bleaching, though the pollution in the flood run-off water may end up killing some corals.

Figure 2. Forecast stress on coral due to warm ocean temperatures for Australia, Jan - Apr 2011. The northern 2/3 of the Great Barrier Reef are under the highest alert level for coral bleaching. Waters are cooler along the southern portion of the reef, due, in part, to the storms that have brought record flooding to portions of Queensland, Australia. Image credit: NOAA Coral Reef Watch.

Long term outlook for world's coral reefs: grim
The large amount of carbon dioxide humans have put into the air in recent decades has done more than just raise Earth's global temperature--it has also increased the acidity of the oceans, since carbon dioxide dissolves in sea water to form carbonic acid. Corals have trouble growing in acidic sea water, and the combined effects of increasing ocean temperatures, increasing acidity, pollution, and overfishing have reduced coral reefs globally by 19 percent since 1950. Another 35 percent could disappear in the next 40 years, even without the impact of climate change, according to a report released in October 2010 by the World Meteorological Organization and the Convention on Biological Diversity. Coral loss has been the most severe in Earth's hottest ocean, the Indian Ocean. Up to 90% of coral cover has been lost in the Maldives, Sri Lanka, Kenya and Tanzania and in the Seychelles. Global warming has heated up most of the tropical ocean surface waters by about 0.5°C (0.9°F) over the past 50 years, and the remarkable bleaching episodes of 1998 and 2010 both occurred when strong (natural) El Niño episodes heated up Pacific tropical waters to record levels. If the Earth continues to heat up this century as expected, coral bleaching episodes will grow more frequent and intense, particularly during strong El Niño episodes. The twin stresses of ocean acidification and increasing ocean temperatures will probably mean that by 2050, it will be difficult for any coral reefs to recover when subject to additional stresses posed by pollution or major storms, according to a talk presented by Stanford climate scientist Ken Caldeira at last month's American Geophysical Union (AGU) meeting.

Figure 3. Departure of sea surface temperature in the Australian region over the past one hundred years, year-by-year (red line), and decade-by-decade (grey bars.) The 2010 value is preliminary and does not include data for December 2010. If ocean temperatures and ocean acidity continue to rise in Australian waters at the same pace as has occurred over the past 100 years, the Great Barrier Reef will be in significant danger by 2050. Image credit: Australian Bureau of Meteorology.

Coral expert J.E.N. Veron, former chief scientist of the Australian Institute of Marine Science, had this to say in an excellent interview he did with Yale Environment 360 last year: "the science is clear: Unless we change the way we live, the Earth's coral reefs will be utterly destroyed within our children's lifetimes.

"You may well feel that dire predictions about anything almost always turn out to be exaggerations. You may think there may be something in it to worry about, but it won't be as bad as doomsayers like me are predicting. This view is understandable given that only a few decades ago I, myself, would have thought it ridiculous to imagine that reefs might have a limited lifespan on Earth as a consequence of human actions. It would have seemed preposterous that, for example, the Great Barrier Reef--the biggest structure ever made by life on Earth--could be mortally threatened by any present or foreseeable environmental change. Yet here I am today, humbled to have spent the most productive scientific years of my life around the rich wonders of the underwater world, and utterly convinced that they will not be there for our children's children to enjoy unless we drastically change our priorities and the way we live."

Reefs are the ocean's canaries and we must hear their call. This call is not just for themselves, for the other great ecosystems of the ocean stand behind reefs like a row of dominoes. If coral reefs fail, the rest will follow in rapid succession, and the Sixth Mass Extinction will be upon us--and will be of our making.

I might add that not only are reefs the ocean's canaries, they are incredibly valuable in their own right. According to the World Meteorological Organization, coral reefs provide economic services--jobs, food and tourism--estimated to be worth $30 billion per year. NOAA put this figure at twelve times higher, $375 billion each year. Corals cover just 0.2% of the world's oceans, but contain about 25% of all marine species.

Next post
I'll be back with a new post on Tuesday at the latest.

Check out wunderground weather historian Christopher C. Burt's post on the notable weather extremes of December 2010. It was truly an extreme month!

Jeff Masters

Coral Bleaching. (Dawnlisa)

Since the end of April the coral in the Andaman sea has started bleaching due to the increase in sea water temperature. If things don't cool down soon the coral may die. You can see the white patches in the photo that are mainly table coral and normally a dark colour.

A parrot fish at the coral reef (BoazR)

as seen from the underwater observatory

coral reef (js64)

Categories: Climate Change

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1052. WaterWitch11 07:13 AM GMT del 10 Gennaio 2011
i remember the 82 flood. absolutely brutal through so many counties. our house had 3 feet of water and 1 foot of mud, cracked the pool, destroyed everything in the house. it was right after christmas and all of our toys we had just gotten were gone. i was sad. i was twelve. so nice to be talking about weather again. Member Since: Agosto 11, 2008 Posts: 3 Comments: 1266

1053. WaterWitch11 07:17 AM GMT del 10 Gennaio 2011
levi, it sounds like your at odds with the weather pattern that has developed for the west coast. is that right? or am i misunderstanding? because i remember a bunch of people on here stating that we would have a dry winter this year. Member Since: Agosto 11, 2008 Posts: 3 Comments: 1266

1054. WaterWitch11 07:22 AM GMT del 10 Gennaio 2011
once again on too late and talking to myself. Member Since: Agosto 11, 2008 Posts: 3 Comments: 1266

1055. PensacolaDoug 07:25 AM GMT del 10 Gennaio 2011
Weird! My temps been bouncing like a ping pong ball! At 6PM it was 40 by 11:30 PM it spiked up to 51 in the last hour and a half its plummeted to 38.5 Weird dynamics with this system coming thru! Member Since: Luglio 25, 2006 Posts: 0 Comments: 4827

1056. PensacolaDoug 07:28 AM GMT del 10 Gennaio 2011
Member Since: Luglio 25, 2006 Posts: 0 Comments: 4827

1057. Levi32 07:45 AM GMT del 10 Gennaio 2011
A meteorological beauty in the making east of Vanuatu: Member Since: novembre 24, 2005 Posts: 586 Comments: 25450

1058. Levi32 07:46 AM GMT del 10 Gennaio 2011
Quoting WaterWitch11: levi, it sounds like your at odds with the weather pattern that has developed for the west coast. is that right? or am i misunderstanding? because i remember a bunch of people on here stating that we would have a dry winter this year. If "we" means the southeast U.S. then yes it was supposed to be, after December. The pattern flip is coming later than expected, but it's likely still coming. The 2-week ensembles are in better agreement on it now than they ever have been. By the end of this month things should be reversed for much of the nation from what they were in December. Member Since: novembre 24, 2005 Posts: 586 Comments: 25450

1059. Levi32 08:04 AM GMT del 10 Gennaio 2011
ASCAT: Broad low center (22 hours old image), but a pretty monsoon trough extending all the way from Fiji to northwest of Australia. Member Since: novembre 24, 2005 Posts: 586 Comments: 25450

1060. Levi32 08:10 AM GMT del 10 Gennaio 2011
This Nice loop of the system shows it is a bit sheared to the northeast, but it is slackening, and the depression is building a nice convective core. This could be something the island of New Caledonia may want to watch very closely over the next few days, as the blocking pattern in place east of Australia will mean this system will take its sweet time crawling SSW, giving it time to strengthen. Member Since: novembre 24, 2005 Posts: 586 Comments: 25450

1061. Levi32 08:14 AM GMT del 10 Gennaio 2011
The ECMWF has a hurricane-strength cyclone crossing New Caledonia in 3-4 days with a nice warm-core signature (notice the 20C isotherms at 850mb showing up at the core of the storm). Member Since: novembre 24, 2005 Posts: 586 Comments: 25450

1065. ColoradoBob1 09:12 AM GMT del 10 Gennaio 2011
Some areas of Queensland have had more than 13 inches (343 millimeters) of rain in the past 24 hours, the Bureau of Meteorology said Monday. Sri Lanka - Batticaloa district recorded the highest rainfall of 312 mm during the weekend, according to Meteorological Department. Thousands of people have been affected by flooding in Thailand’s southern provinces following six days of torrential rains, local media report. Thousands evacuated because of Malaysian floods; three dead Member Since: Agosto 13, 2010 Posts: 0 Comments: 159

1066. RTLSNK (Mod) 11:11 AM GMT del 10 Gennaio 2011
31F and sleet in Macon, Ga this morning: Member Since:* Settembre 3, 2008 Posts: 0 Comments: 15180

1067. RTLSNK (Mod) 11:53 AM GMT del 10 Gennaio 2011
I'm going back to sleep, wake me when it warms up. :) Member Since: Settembre 3, 2008 Posts: 0 Comments: 15180

1068. kellnerp 12:07 PM GMT del 10 Gennaio 2011
Closed for 3 inches? South Bend Indiana closed schools on Monday because 25 inches dropped on Saturday. When I walked to the shed snow was over my kneecaps. But a flake hasn't fallen since Saturday night, the roads were clear all Sunday, yet they still closed the schools on Monday. Go figure. The models show more to come. Another blast by the end of the week and a week later comes another. Member Since: Settembre 1, 2003 Posts: 0 Comments: 170

1069. islander101010 12:39 PM GMT del 10 Gennaio 2011
its there summer but the southern pacific has been active of recent looks like it should continue. good for surfers all over the pacific Member Since: Settembre 11, 2010 Posts: 0 Comments: 2967

1070. biff4ugo 01:53 PM GMT del 10 Gennaio 2011
Good Morning Masterians! I am puzzled by part of the blog. It talks about increased bleaching during El Nino, and I understand how a warm Pacific surface could bring warmer waters to the reefs. But he says the same for this years La Nina event. Shouldn't a cold Pacific decrease bleaching? What about sea level rise? Shouldn't sea level rise help decrease bleaching by making the reefs deeper? I know they need light and the depth is small but it should help, right? The canary analogy is good, and making a stronger canary sounds dumb but... couldn't genetics folks work on the symbiotic algae to develop a more heat tolerant strain? Introducing a tougher algae into the bleached coral could help them recover and build stress resistant reefs. Member Since: Dicembre 28, 2006 Posts: 107 Comments: 1177

1071. StormJunkie 01:57 PM GMT del 10 Gennaio 2011
Morning all Icy here in the Holy City. And that's not a weak hook echo in the upper right of the last few frames is it? Snownado? Is that even possible? There were reports of thunder snow and sleet with that cell. Member Since: Agosto 17, 2005 Posts: 26 Comments: 15218

1072. Skyepony (Mod) 02:11 PM GMT del 10 Gennaio 2011
Quoting biff4ugo: Good Morning Masterians! I am puzzled by part of the blog. It talks about increased bleaching during El Nino, and I understand how a warm Pacific surface could bring warmer waters to the reefs. But he says the same for this years La Nina event. Shouldn't a cold Pacific decrease bleaching? What about sea level rise? Shouldn't sea level rise help decrease bleaching by making the reefs deeper? I know they need light and the depth is small but it should help, right? The canary analogy is good, and making a stronger canary sounds dumb but... couldn't genetics folks work on the symbiotic algae to develop a more heat tolerant strain? Introducing a tougher algae into the bleached coral could help them recover and build stress resistant reefs. During La Nina the west edge of the Pacific tends to pool extra heat. That's why the Great Barrier Reef is currently at higher risk. That oil spill & tanker that drug across that area last year probably added stress as well. The sea level rise has been partially due to warm water expanding. So probably not much offset there. If only there was instant monetary gains to genetically modifying the coral. Like everything else to make it better isn't cost effective enough. Now if we could GM it to withstand treating it with something else they could sell & make money off like oil dispersant too we may have something. Member Since: Agosto 10, 2005 Posts: 144 Comments: 29294

1073. Neapolitan 02:31 PM GMT del 10 Gennaio 2011
Quoting Skyepony: If only there was instant monetary gains to genetically modifying the coral. Like everything else to make it better isn't cost effective enough. True. If large-scale bio-engineering of the coral reefs could be somehow monetized, you can bet corporations would find a way to do so. But I would say that instead of tinkering with the coral to make it more resistant to heat--a cure that could be worse than the disease, unintended consequences being what they are and all--sane people should instead yank the whole GW issue out of the hands of politicians and give it back to scientists who study such things, which is where it belongs. Maybe then we could start to make headway on solving the warming planet problem. That would seem to make more sense than sitting back and watching as one coal mine canary after another keels over and dies, then arguing with those who insist that the canaries aren't truly dead, and even if they are we didn't kill them, and even if we did it's no big deal. "The twin stresses of ocean acidification and increasing ocean temperatures will probably mean that by 2050, it will be difficult for any coral reefs to recover when subject to additional stresses posed by pollution or major storms, according to a talk presented by Stanford climate scientist Ken Caldeira at last month's American Geophysical Union (AGU) meeting." Some may not see this snippet of Dr. Masters' post as sad, but I do. Member Since: novembre 8, 2009 Posts: 4 Comments: 11153

1074. MissNadia 02:32 PM GMT del 10 Gennaio 2011
Good Morning, Coastal Carolina is catching it today!!! NC STATE PORTS, WILMINGTON, North Carolina (PWS) Updated: 1 min 44 sec ago 27.8 °F Heavy Snow Freezing Fog Windchill: 19 °F Humidity: 100% Dew Point: 28 °F Wind: 8.6 mph from the NNE Wind Gust: 9.6 mph Pressure: 30.39 in (Steady) Visibility: 0.2 miles Pollen: .40 o Member Since: Luglio 27, 2008 Posts: 0 Comments: 2674

1075. presslord 02:36 PM GMT del 10 Gennaio 2011
Quoting MissNadia: Good Morning, Coastal Carolina is catching it today!!! NC STATE PORTS, WILMINGTON, North Carolina (PWS) Updated: 1 min 44 sec ago 27.8 °F Heavy Snow Freezing Fog Windchill: 19 °F Humidity: 100% Dew Point: 28 °F Wind: 8.6 mph from the NNE Wind Gust: 9.6 mph Pressure: 30.39 in (Steady) Visibility: 0.2 miles Pollen: .40 o You're gonna catch it if you don't stop!!!!!!!!!!!!!! Member Since: Agosto 13, 2007 Posts: 0 Comments: 10377

1076. largeeyes 03:05 PM GMT del 10 Gennaio 2011
Snowin like crazy on my drive in, get here, almost nothing has fallen. Crazy stuff for 15 miles. Member Since: Agosto 22, 2006 Posts: 0 Comments: 1381

1077. Walshy 03:05 PM GMT del 10 Gennaio 2011
Quoting presslord: You're gonna catch it if you don't stop!!!!!!!!!!!!!! I wonder how bad CHARLESTON, SC is going to get it! Member Since: Maggio 17, 2009 Posts: 2 Comments: 618

1078. caneswatch 03:05 PM GMT del 10 Gennaio 2011
Quoting presslord: You're gonna catch it if you don't stop!!!!!!!!!!!!!! Coastal Carolinas? lol Member Since: Ottobre 8, 2008 Posts: 14 Comments: 4473

1079. ChillinInTheKeys 03:35 PM GMT del 10 Gennaio 2011
NEW BLOG!!! Member Since: Agosto 18, 2008 Posts: 0 Comments: 448

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