ST. PETERSBURG, Fla.— Late-summer water temperatures near the Florida Keys were warmer by nearly 2 degrees Fahrenheit in the last several decades compared to a century earlier, according to a new study by the U.S. Geological Survey.
Researchers indicate that the warmer water temperatures are stressing corals and increasing the number of bleaching events, where corals become white resulting from a loss of their symbiotic algae. The corals can starve to death if the condition is prolonged.
“Our analysis shows that corals in the study areas are now regularly experiencing temperatures above 84 F during July, August and September; average temperatures that were seldom reached 120 years ago,” said Ilsa Kuffner, a USGS research marine biologist and the study’s lead author. “When corals are exposed to water temperatures above 84 F they grow more slowly and, during extended exposure periods, can stop growing altogether or die.”
The new analysis compares water temperatures during two time periods a century apart at two of Florida’s historic offshore lighthouses – Fowey Rocks Lighthouse, off Miami, and Carysfort Reef Lighthouse, off Key Largo, Florida. The first period included data from 1879 to 1912, while the second period spanned from 1991 to 2012. Temperatures at a third area, a reef off Islamorada, Florida, were also monitored from 1975 to 2007.
“What’s interesting is that the temperature increase observed during this recent 32-year period was as large as that measured at the lighthouses spanning 120 years,” said Kuffner. “This makes it likely the warming observed at the lighthouses has actually occurred since the 1970s.”
The study indicates that August is consistently the month when Florida’s ocean temperatures peak. In the analysis of recent decades, average temperatures for August have been at or very close to 86 F. At Fowey Lighthouse from 1879 to 1912, the average August temperature was just 84.2 F. Temperatures this August at the same location, though not included in the study, averaged 87 F.
Coral bleaching is currently underway in the Florida Keys, highlighting the real-time impact that warmer ocean temperatures are having on reefs. Corals can recover from bleaching if the waters cool down within a few weeks, but mortality usually ensues if corals remain bleached longer than a month or two.
The study, “A century of ocean warming on Florida Keys coral reefs: Historic in-situ observations,” was recently published in the journal Estuaries and Coasts and is available via open access.
Abstract
There is strong evidence that global climate change over the last several decades has caused shifts in species distributions, species extinctions, and alterations in the functioning of ecosystems. However, because of high variability on short (i.e., diurnal, seasonal, and annual) timescales as well as the recency of a comprehensive instrumental record, it is difficult to detect or provide evidence for long-term, site-specific trends in ocean temperature. Here we analyze five in situ datasets from Florida Keys coral reef habitats, including historic measurements taken by lighthouse keepers, to provide three independent lines of evidence supporting approximately 0.8 °C of warming in sea surface temperature (SST) over the last century. Results indicate that the warming observed in the records between 1878 and 2012 can be fully accounted for by the warming observed in recent decades (from 1975 to 2007), documented using in situ thermographs on a mid-shore patch reef. The magnitude of warming revealed here is similar to that found in other SST datasets from the region and to that observed in global mean surface temperature. The geologic context and significance of recent ocean warming to coral growth and population dynamics are discussed, as is the future prognosis for the Florida reef tract.
Coral reefs in most of the Caribbean, including much of Florida near the coasts, have been badly degraded by a combination of overfishing, pollution, and disease. That is the main reason Florida coral reefs are in such trouble. Nutrients cause more algae to grow. If this algae coats corals, they die. Back in the day, there were different fish which grazed on this algae, so the corals lived. When the fish were overfished, sea urchins also grazed on the algae. When the main sea urchin of the area, the black sea urchin, died off in the 1980s, there was nothing left that could keep up with grazing the algae. See:
http://www.redorbit.com/education/reference_library/animal_kingdom/echinoderms/1112834408/black-sea-urchin-diadema-antillarum/
These were the main reasons for coral die offs near mainland Florida in the 1980s and later (and in Jamaica, and elsewhere in the Caribbean, but not yet in places like Belize, as far as I know). Hopefully the corals near the Dry Tortugas are still pretty healthy.
All this is well known. It is also well known, to coral scientists, that corals recover from bleaching events “unexpectedly” well, provided that they haven’t been degraded by pollution, overfishing, etc. Some examples of “unexpected” coral regrowth from bleaching:
http://www.heraldsun.com.au/news/breaking-news/australian-reef-recovers-from-bleaching/story-e6frf7kf-1226612928361?nk=6e0539cb149220fb1775ccf74c12839e
http://www.nature.com/nclimate/journal/v2/n2/full/nclimate1330.html?WT.ec_id=NCLIMATE-201202
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0080536
http://www.sciencedaily.com/releases/2009/04/090423100817.htm
http://www.reefresilience.org/coral-reefs/stressors/bleaching/resistance-tolerance-and-recovery/
Virtually all of us want health coral reefs. This kind of alarmist article is about keeping the troops in line for the global warming battle, in my opinion. If it were about recovering coral reefs, it would be about reducing pollution and overfishing, and restoring algae grazers. We all know that higher ocean temperatures can cause coral bleaching. Most of us do now know (yet) that in the great majority of cases, healthy coral reefs — those not yet degraded — recover and regrow, even with warmer waters.
The inferences are standard CAGW, and almost certainly biologically wrong. I snorkel and dive these coral reefs from the Keys to Fort Lauderdale.
The alarmist tip off is 5 sites in the Keys, e.g. Islamorada. The problem is urbanization (development) and the subsequent sediment and detritus laden rainwater runoff into near shore waters inhabited by the reefs. Not to mention that treated sewage eddluent is also usually piped to sea since there is no where else to put it in those parts. The decomposition of the ‘pollution’ generates trace amounts of hydrogen sulfide, a classic problem in any saltwater aquarium filter.
The L50 of H2S for coral, shrimp, and crab is about 30ppb! Disrupts their oxygen metabolism, worse than cyanide. There are a number of oceanographic and marine ecosystem papers that document this as the main problem for coastal reef bleaching, in excruciating detail. BTW is also true for Australian Great Barrier reef bleaching events, which usually follow flooding and the associated sediment laden runoff into the ocean. Often, the reefs can eecover if the ‘pollution is a pulse and not continuous.
Warmer water accelerates the organic decomposition, so raises the H2S concentration. That is the temperature link.
Wrote about this in the essay shell games for the upcoming book. Details there, not here.
I wonder if the recent absence of tropical storms and hurricanes around Florida has anything to do with the reported higher SST at these particular locations. These storms transport heat from the oceans to the atmosphere and to the land. Also, I took a look at the HADCRUT temperature record for Orlando in the center of the Florida Peninsula, and it has been trending slightly cooler for the last 60 years. Just take a look at where orange trees grow and survive the winter now compared to 1950’s and 60’s.
Looks like they compared -AMO to +AMO and found it was different. Amazingly brilliant these clientologists.
“What’s interesting is that the temperature increase observed during this recent 32-year period was as large as that measured at the lighthouses spanning 120 years,” said Kuffner. “This makes it likely the warming observed at the lighthouses has actually occurred since the 1970s.”
That’s what I was thinking, too…or don’t they recogniise the AMO as a valid process?
Well after pulling their supplementary data, they are not actually measuring the coral reefs, just some lighthouses built at the outer edge of the reef and not even the same lighthouses or same locations. The only close records are all at Fowey rocks which is the extreme north edge of the keys very close to the gulf stream. Peak temps were greater in the 1878 time frame but that must have been massaged out of the data somehow, averages can be very convenient. Further the record is not continuous nor of the same points, their 32 year span is not a single span of a single point compared to another 32 year span. So I am thinking garbage in garbage out. It would be interesting to include data from the entire period 1870 to present, except of course that doesn’t exist. Bleaching of coral as a previous poster pointed out is just the corals request for a new type of algae, happens all the time. Staghorn and elkhorn coral was a big collectors item at one time as well as being very susceptible to damage from careless divers. Finally not a lot of data on the condition of the coral reef from the earlier period, as far as we know it could have been the same, worse or better. Anyhow not a very careful study.
OMG now warm water that kills coral? I always thought it was cold. If not, why aren’t there coral reefs off Long Island.?
Nice circular argument. Ocean temperatures increase because of global warming, and global warming is measured through increasing Ocean temperatures.
I downloaded the raw temperature data from the SI section of the report link. What I was looking for was the depth of the temperature sensors. I did not find it in a quick look; I’ll take a more thorough look later.
As any diver knows, there can be sharp thermoclines in the ocean. Temperatures at the surface seldom survive a descent of even 10 feet, and boy do you notice them when you pass through. I was diving in Bonaire in April; Panama City, Florida in June and Hawaii (big island) in August. I would have loved to see water temperatures at 84° (F) in any of those places. Instead at any depth I could be fully submerged where there was anything interesting to look at (including corals), water temperatures were always in the 78° – 81° range (my dive computer records water temp).
In other words, the water temps at the measured locations might not be a valid proxy for temps where the coral live.
Sometimes a picture is worth a thousand words.
http://species-identification.org/species.php?species_group=caribbean_diving_guide&id=355
Yes and, this projection of bird extinction was released by the Audubon Society and appeared on the front page of my local paper tonight.
The irony is, they’re probably right, but not because of Global Warming. Because of the hilltop cuisinarts that will be dotting every hilltop in the future.
http://news.heartland.org/sites/default/files/imagecache/heartlander-thumb-promo-large/wind_turbine_bird_1.jpg
This is too goofy to be true. I’ll have a post about it in the morning. Unbelievable.
Their buddies have just recognised that the oceans impact climate (main driver of climate) … these guys need to get with the story that the air above the oceans has bugger all impact on anything other than their funding.
They might also acquaint themselves with the fact that corals in vast areas greater than modern times existed with sea temperatures greater than modern times.
They might acquaint themselves with the Red Sea coral habitations.
Nice observation. Had not thought about the Red Sea temps. Ah, isn’t life’s biodiversity wonderful?
Except Coral Bleaching in the area has been pretty conclusively linked to dust from Africa. But the studies coming to that conclusion were done by old white males who did not have the benefit of the enlightened world view that is required to do real science. Those old studies can be safely ignored.
Or could possibly a correlation between the DEPTH of the water in which the coral grows? shallow/warmer, deeper/cooler. and could that be related to storm surges/ hurricanes and the beat goes on. One answer to one problem related to mother nature never works, and for me anyway climate always changes and have effects every where. day in day out, year in year out.
“Researchers indicate that the warmer water temperatures are stressing corals and increasing the number of bleaching events, where corals become white resulting from a loss of their symbiotic algae.”
You conveniently forget to mention that cooler water also causes coral bleaching.
“When corals are exposed to water temperatures above 84 F they grow more slowly and, during extended exposure periods, can stop growing altogether or die.”
Of course the Coral Triangle has the greatest marine biodiversity and its water temperature is 84-88 F. Perhaps you mean “start growing all together or live.”
Meanwhile China is literally bulldozing coral atolls and reefs in the South China Sea to make islands for military use.
http://www.bbc.co.uk/news/world-asia-china-29139125
Warmer than the 1930s? Certainly no warmed by the transfer of radiative co² energy into the oceans.
It’s downright ridiculous, that narrow-minded people only look at the Highs while losing sight of the Lows in times of a “Global Warming” hysteria and never vice versa.
Are they all so obtuse not to include the overall picture into their conclusions?
This behavior can never ever be science ion the least.
Sounds like they are trying to cover up for the damage done in 2010.
“Severe 2010 Cold-Water Event Caused Unprecedented Mortality to Corals of the Florida Reef Tract and Reversed Previous Survivorship Patterns ”
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0023047
Blathering Idiots, they are. Any good marine biologist knows that corals expel their symbiotic algae at various temperatures in order to take in a different one. If these idiots came back three or six months later, they would find that the corals were all colorful again. Duh!
Clearly the coral reefs are having environmental issues around the world. But this has little or nothing to do with CO2.
First of all, the reefs are ancient. The temperature rise in the past decades is hardly unprecedented over the eons of reef life. Keep in mind, from 12000 years ago to 4000 years ago, sea level rose 54 inches a century on average. That dwarfs the rates today.
Second, the reef in nearby Cuba are pristine. Why are the keys ruined but Cuba is fine? Kind of rules out “global warming”. I guess communism has at least one benefit.
I don’t know the details, but some folks say the over-fishing/loss of the Parrot Fish is the problem. The Parrot Fish chew on the reefs and clean them. Perhaps someone with more knowledge of this could comment.
If I had authored this paper I would withdraw it with an apology after reading these comments and seriously consider a career change. If I decided to stay in climatology I would completely rewrite the paper using the comments as a guide to make my paper more robust and accurate while also making sure that the paper was not biased with any preconceived outcome, agenda, or funding. But we all know none of those things will happen because this is not science, it is propaganda.
There is the “slight” change in the prorgam. It’s actually not global warming anymore, since earth is cooling down since 2005 it’s now called climate change instead. There is also the slight misshap of the temperatures rising a few years prior to the rise in the levels of CO2.I’m not going to go into details on a high school question but you might want to look into climate gate (it’s true, the mails presented by what is American party in the US was taken out of context but I’ve read the mails decided fo myself and the pro-climate change propaganda is based on B.S. and even the ones spreading it know it) and you might have a look at articles google-schollar finds.IMO: it’s a politically based nonscientific topic. A war between American republicans and democrats that spread over the rest of the world with Al Gore. The people have been frightened into believing a bunch of blury idieas that were later discovered not to be true. The evidence is there but the public belief is slow to change.BUT ! The consequence of the hole anti carbon propaganda are really good. More renewable energy is being used.