Dr. Jeff Masters' WunderBlog

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

Posted by: Dr. Jeff Masters, 16:50 GMT le 07 janvier 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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901. Grothar 22:59 GMT le 09 janvier 2011
Member Since: 17 juillet 2009 Posts: 56 Comments: 19488

902. atmoaggie 23:01 GMT le 09 janvier 2011
Quoting LoveStormsatNight: This one, atmoaggie. Oh, I was hoping you found one, or they started an ob site at Manchac. Would be a great place for one...and would read higher for all of our east wind events that any of those on the southshore. (And people live there, too...just not very many.) Member Since: 16 août 2007 Posts: 6 Comments: 12461

903. atmoaggie 23:02 GMT le 09 janvier 2011
Quoting JFLORIDA: The city of New Orleans has a system of levees too. Its interesting reading atmo. You do know what I do, right? Not that I couldn't still learn a thing or 2 about hydrology... Member Since: 16 août 2007 Posts: 6 Comments: 12461

905. Grothar 23:05 GMT le 09 janvier 2011
Quoting atmoaggie: You do know what I do, right? Not that I couldn't still learn a thing or 2 about hydrology... I do, that is why I never argue with you. How you doing atmo? Member Since: 17 juillet 2009 Posts: 56 Comments: 19488

906. TampaFLUSA 23:07 GMT le 09 janvier 2011
Quoting JFLORIDA: Station BURL1 - Southwest Pass, LA These surface winds keep increasing. I think they are past impressive. Over 50 mph ....I wonder if a slight surge will affect the NW coast of Florida and the big bend area which is prone to flooding. Member Since: 21 juin 2007 Posts: 10 Comments: 1656

907. atmoaggie 23:08 GMT le 09 janvier 2011
Quoting Grothar: I do, that is why I never argue with you. How you doing atmo? That's just one subject, Gro...I can admit when I don't know WTH I am talking about, too. Member Since: 16 août 2007 Posts: 6 Comments: 12461

908. Grothar 23:11 GMT le 09 janvier 2011
Quoting atmoaggie: That's just one subject, Gro...I can admit when I don't know WTH I am talking about, too. Not me. Never! I never apologize!! I'm sorry, but it's just the way I am. (In an out watching the game... another close one) Member Since: 17 juillet 2009 Posts: 56 Comments: 19488

909. KEEPEROFTHEGATE (Mod) 23:14 GMT le 09 janvier 2011
i have made some changes in the model run area its all self updating now check it out Link Member Since: 15 juillet 2006 Posts: 143 Comments: 40375

911. KoritheMan 23:16 GMT le 09 janvier 2011
Very dry air noted from 950 to 700 mb on the New Orleans NAM sounding (GFS shows it too): Could explain the lack of appreciable winter precipitation in the area, since areas farther west and north of this sounding are more than cold enough at the surface to support frozen precipitation. Member Since: 7 Mars 2007 Posts: 408 Comments: 15418

912. Patrap 23:17 GMT le 09 janvier 2011
Member Since: 3 juillet 2005 Posts: 370 Comments: 111244

913. KoritheMan 23:17 GMT le 09 janvier 2011
Quoting KEEPEROFTHEGATE: i have made some changes in the model run area its all self updating now check it out Link I bookmarked a few of those. Thanks. Member Since: 7 Mars 2007 Posts: 408 Comments: 15418

914. IKE 23:31 GMT le 09 janvier 2011
Sleeting outside my window right now and 41.9 degrees. Member Since: 9 juin 2005 Posts: 23 Comments: 37044

915. Grecojdw 23:31 GMT le 09 janvier 2011
Hey you guys in FWB/Niceville, FL. Look at the Accuweather current conditions for hour area when you type in the 32548 Zip code. It says current conditions in Fort Walton Beach, Fl Rain/Snow at 43F. We are already below are forecast low so I want to know what is going on? Member Since: 6 janvier 2010 Posts: 0 Comments: 339

916. flsky 23:32 GMT le 09 janvier 2011
Quoting LoveStormsatNight: On the east side of Lake Pontchartrain, the water level was below normal and suddenly leaped up, as if there were a seiche. Very odd. Have you found any explanation for this? Member Since: 24 octobre 2006 Posts: 0 Comments: 1265

917. Grecojdw 23:32 GMT le 09 janvier 2011
Quoting IKE: Sleeting outside my window right now and 41.9 degrees. What is going on....my thermometer just drop to 41F and it is reporting rain/snow in my area??? Member Since: 6 janvier 2010 Posts: 0 Comments: 339

918. IKE 23:37 GMT le 09 janvier 2011
All I see is rain at FWB,FL. locations. Member Since: 9 juin 2005 Posts: 23 Comments: 37044

919. KoritheMan 23:39 GMT le 09 janvier 2011
Quoting Grecojdw: Hey you guys in FWB/Niceville, FL. Look at the Accuweather current conditions for hour area when you type in the 32548 Zip code. It says current conditions in Fort Walton Beach, Fl Rain/Snow at 43F. We are already below are forecast low so I want to know what is going on? I suspected earlier after reviewing doppler radar data that the surface low moving across the Gulf of Mexico is moving at a faster clip than what was initially thought. Hence, the precipitation shield arrived faster. My hunch might not be correct of course, but that's my two cents. Like IKE though, I don't see any snow observations in the area, either. Member Since: 7 Mars 2007 Posts: 408 Comments: 15418

920. HurrMichaelOrl 23:41 GMT le 09 janvier 2011
As of 4:56 pm central time, Milton, FL was reporting "Small Hail/Snow Pellets Rain" at 43 F. Interesting! Member Since: 13 juillet 2007 Posts: 0 Comments: 587

922. atmoaggie 23:42 GMT le 09 janvier 2011
Quoting LoveStormsatNight: This was the link for the smaller surge I talked about on the west side of Lake Ponchartrain, atmoaggie. And this was the link further east, with the seiche (?) I know now which ones you were looking at. Use the tidesandcurrents site all the time... ;-) The New Canal water level obs are interesting. Not sure what would cause that...it doesn't appear to be winds. The sudden drop in water levels at the same time as a drop in air pressure (that's backwards) and a drop in air temperature (irrelevant). shrug I dunno. Seems like there should have been seismic activity to cause that, if it's real. That's a very quick 1 foot drop and rise in water levels. Member Since: 16 août 2007 Posts: 6 Comments: 12461

924. Grecojdw 23:45 GMT le 09 janvier 2011
Quoting IKE: All I see is rain at FWB,FL. locations. I'm just noting the current conditions on the Accuweather when you type the zip for my region...and look...it just changed over to just rain on Accuweather:o...I guess it was a typo or a glitch in their system. But it is still to note that we are below our forecast low for this area currently. Member Since: 6 janvier 2010 Posts: 0 Comments: 339

925. atmoaggie 23:46 GMT le 09 janvier 2011
Quoting LoveStormsatNight: Can't be sure why. There've been strong east winds all day that piled up water about a foot to a foot and a half above expected levels on the west side of the lake. If the wind suddenly let up for a time, the water can rock back quite suddenly, like water rocking in a bathtub. When a lake rocks, it is called a seiche. It can be triggered by strong winds or sudden pressure changed on one side of a lake, or a strong wind across an entire lake relaxing or changing direction. On Saturday, June 26, 1954 at 9:30 am a seiche hit the Chicago waterfront triggered by a squall line that had affected Lake Michigan a few hours earlier. The water rose 2-4 feet in the lake, but it funneled to 10 feet high as it struck the North Avenue Pier (groin). It was crowded with fisherman enjoying a sunny Saturday morning. All the fisherman were swept off the groin, and 8 of them were drowned. Winds at 30 mph for a while, then to 20 mph cannot explain that water level drop and rise. And the difference in winds from one part of the lake to another for this low pressure should not be significant. Member Since: 16 août 2007 Posts: 6 Comments: 12461

926. HurrMichaelOrl 23:47 GMT le 09 janvier 2011
Look on nws.noaa.gov, and search Milton, FL. Member Since: 13 juillet 2007 Posts: 0 Comments: 587

932. TampaFLUSA 00:00 GMT le 10 janvier 2011
Quoting LoveStormsatNight: What actually happened in Chicago is that the squall line traveled across Lake Michigan in the predawn hours, and triggered a surge that reached 5.5 to 6 feet at Michigan City. Lake Michigan then rocked back towards Chicago and caused the fatalities there. A true seiche can keep a lake rocking back and forth for several oscillations. Here is the report on the 1954 seiche disaster in Chicago. They can happen on lakes in areas where earthquakes occur. Member Since: 21 juin 2007 Posts: 10 Comments: 1656

934. atmoaggie 00:03 GMT le 10 janvier 2011
Quoting LoveStormsatNight: I didn't say it was a seiche, atmoaggie. I said it sorta looked like one. The seiche in Lake P from the Chile earthquake last February looked like this: I would expect any others to have the same unsettled-for-a-time effect, too. Though the steady east winds would dampen that some. Member Since: 16 août 2007 Posts: 6 Comments: 12461

936. atmoaggie 00:03 GMT le 10 janvier 2011
Quoting LoveStormsatNight: Anyway I'm not sure the Lake Pontchartrain causeway allows water to flow through quickly enough to let a seiche through. I've never seen the causeway. Does, would, did. Member Since: 16 août 2007 Posts: 6 Comments: 12461

937. Skyepony (Mod) 00:05 GMT le 10 janvier 2011
There was a seiche in Lake Pontchartrain early last year from an earthquake in Chile. Masters had a blog on it. Member Since: 10 août 2005 Posts: 144 Comments: 29240

938. atmoaggie 00:05 GMT le 10 janvier 2011
Quoting LoveStormsatNight: Anyway I'm not sure the Lake Pontchartrain causeway allows water to flow through quickly enough to let a seiche through. I've never seen the causeway. BTW: that's the causeway in my avatar. Sunset from, well, Sunset Point in Mandeville. Member Since: 16 août 2007 Posts: 6 Comments: 12461

939. Ossqss 00:06 GMT le 10 janvier 2011
Anyone remember the events last year in Lake Pontchartrain ? http://en.wikipedia.org/wiki/Seiche "The February 27, 2010 Chile earthquake produced a seiche on Lake Pontchartrain, Louisiana with a height of around 0.5 feet." http://neic.usgs.gov/neis/eq_depot/2010/eq_100227_tfan/neic_tfan_t.html Member Since: 12 juin 2005 Posts: 6 Comments: 8154

940. nash28 00:06 GMT le 10 janvier 2011
Temp dropping like a stone here in Summerville, SC. Definitely will be cold enough to support the ice predictions we have. Now we're just waiting for the lower troposphere to moisten up so these dewpoints rise. Anticipate waking up to a mess in the morning. Member Since: 11 juillet 2005 Posts: 190 Comments: 16972

943. nash28 00:12 GMT le 10 janvier 2011
Quoting LoveStormsatNight: If this observation is representative for you, you'll have a lot of evaporational cooling tonight. With no sun to work against it. It appears that way. Member Since: 11 juillet 2005 Posts: 190 Comments: 16972

944. Patrap 00:12 GMT le 10 janvier 2011
NEXRAD Radar New Orleans, Base Reflectivity 0.50 Degree Elevation Range 124 NMI Member Since: 3 juillet 2005 Posts: 370 Comments: 111244

945. PcolaDan 00:13 GMT le 10 janvier 2011
Quoting HurrMichaelOrl: As of 4:56 pm central time, Milton, FL was reporting "Small Hail/Snow Pellets Rain" at 43 F. Interesting! Was having connection problems. I was out grilling about 4 pm and had a good sleet shower came through. End up with some on the plate with my ribs. :) Member Since: 22 août 2008 Posts: 12 Comments: 6008

946. Grecojdw 00:14 GMT le 10 janvier 2011
Quoting nash28: Temp dropping like a stone here in Summerville, SC. Definitely will be cold enough to support the ice predictions we have. Now we're just waiting for the lower troposphere to moisten up so these dewpoints rise. Anticipate waking up to a mess in the morning. My sister lives in Ladson just right outside of Summerville. She got some snow during the last major event. They were at the flea market there when it started to snow right after Christmas. My Floridian parents were not use to that and had to delay their travel back into town by a day:) Member Since: 6 janvier 2010 Posts: 0 Comments: 339

947. Patrap 00:15 GMT le 10 janvier 2011
Rainbow WV Member Since: 3 juillet 2005 Posts: 370 Comments: 111244

950. Patrap 00:18 GMT le 10 janvier 2011
Member Since: 3 juillet 2005 Posts: 370 Comments: 111244

951. TampaFLUSA 00:18 GMT le 10 janvier 2011
The 2006 Gulf of Mexico earthquake was a 5.8 magnitude[1] earthquake that hit the Gulf of Mexico on September 10, 2006, about 250 miles west-southwest of Anna Maria, Florida around 10:56 AM EDT. The quake was reportedly felt from Louisiana to Florida. There were no reports of major damages or casualties[2]. Items were knocked from shelves and seiches were observed in swimming pools in parts of Florida [1]. The earthquake was described by the USGS as a midplate earthquake, the largest and most widely felt recorded in the past three decades in the region[1]. Member Since: 21 juin 2007 Posts: 10 Comments: 1656

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