The coral reef crisis: The critical importance of

Posted on October 3, 2009 by ovehblog

coral

Temperature-induced mass coral bleaching causing mortality on a wide geographic scale started when atmospheric CO2 levels exceeded 320 ppm. When CO2 levels reached 340 ppm, sporadic but highly destructive mass bleaching occurred in most reefs world-wide, often associated with El Niño events. Recovery was dependent on the vulnerability of individual reef areas and on the reef’s previous history and resilience. At today’s level of 387 ppm, allowing a lag-time of 10 years for sea temperatures to respond, most reefs world-wide are committed to an irreversible decline. Mass bleaching will in future become annual, departing from the 4 to 7 years return-time of El Niño events. Bleaching will be exacerbated by the effects of degraded water-quality and increased severe weather events. In addition, the progressive onset of ocean acidification will cause reduction of coral growth and retardation of the growth of high magnesium calcite-secreting coralline algae. If CO2 levels are allowed to reach 450 ppm (due to occur by 2030–2040 at the current rates), reefs will be in rapid and terminal decline world-wide from multiple synergies arising from mass bleaching, ocean acidification, and other environmental impacts. Damage to shallow reef communities will become extensive with consequent reduction of biodiversity followed by extinctions. Reefs will cease to be large-scale nursery grounds for fish and will cease to have most of their current value to humanity. There will be knock-on effects to ecosystems associated with reefs, and to other pelagic and benthic ecosystems. Should CO2 levels reach 600 ppm reefs will be eroding geological structures with populations of surviving biota restricted to refuges. Domino effects will follow, affecting many other marine ecosystems. This is likely to have been the path of great mass extinctions of the past, adding to the case that anthropogenic CO2 emissions could trigger the Earth’s sixth mass extinction.

J.E.N. Veron, O. Hoegh-Guldberg, T.M. Lenton, J.M. Lough, D.O. Obura, P. Pearce-Kelly, C.R.C. Sheppard, M. Spalding, M.G. Stafford-Smith, A.D. Rogers (2009) The coral reef crisis: The critical importance of <350 ppm CO2. Marine Pollution Bulletin 58:1428-1436

Slimed by “CO2 science”

Posted on October 1, 2009 by ovehblog

An AGW skeptic organization “The Center for the Study of Carbon Dioxide and Global Change” just posted a summary of a recent paper I was lead author on (Bruno et al. 2009 – Jez blogged about it here) on their website CO2 science: “Corals vs. Macroalgae in a CO2-Enriched and Warmer World: Which is destined to predominate?”

“Slimed” is probably an exaggeration or inaccurate description. They didn’t criticize me or the work. And they got much of the science right. But they subtly ignore a key take home message (i.e., we didn’t say there was NO problem, we said that the macroalgae problem is being exaggerated) and incorrectly imply the paper has something to do with coral-seaweed competition in the future (it doesn’t).

Background: The authors write that one of the great concerns of marine scientists is that “coral reefs are moving toward or are locked into a seaweed-dominated state,” based on observations of what occurred on several Jamaican reefs during the 1980s, which concerns are often parroted by climate alarmists such as Al Gore (An Inconvenient Truth) and Michael Mann and Lee Kump (Dire Predictions).

True. But did Al Gore and Michael Mann really address coral reef phase shifts and macroalgae in their movies about climate change? Haven’t seen them…

What was done: To assess the generality of these claims, Bruno et al. “analyzed 3,581 quantitative surveys of 1,851 reefs performed between 1996 and 2006 to determine the frequency, geographical extent, and degree of macroalgal dominance of coral reefs and of coral to macroalgal phase shifts around the world.”

True

What was learned: The five marine researchers found that “the replacement of corals by macroalgae as the dominant benthic functional group is less common and less geographically extensive than assumed,” noting that “only 4% of reefs were dominated by macroalgae (i.e., >50% cover).” In fact, across the Indo-Pacific, where regional averages of macroalgal cover were 9-12%, they found that “macroalgae only dominated 1% of the surveyed reefs.” In addition, they learned that “between 1996 and 2006, phase shift severity decreased in the Caribbean, did not change in the Florida Keys and Indo-Pacific, and increased slightly on the Great Barrier Reef.”

True

What it means: Bruno et al. state that “coral reef ecosystems appear to be more resistant to macroalgal blooms than assumed,” and that “the mismatch between descriptions of reef degradation in the literature and patterns in nature was caused by the generalization of a relatively small number of examples,” concluding that their analysis suggests that “the macroalgae problem has been exaggerated,” and that “overall,” there has been “no general recent trend (i.e., post-1995) toward macroalgal dominance.” In fact, they say that “macroalgal cover may currently be close to the historical baseline across most of the world.”

Well, we did say that, but we also said:

“Coral abundance on reefs around the world began to decline several decades ago (Gardner et al. 2003, Bruno and Selig 2007) due to a variety of factors including predator and disease outbreaks, poor land use practices, destructive fishing techniques, and ocean warming (Glynn 1993, McManus et al. 1997, Aronson and Precht 2001, Hughes et al. 2003).”

Point being, that we didn’t say reefs haven’t been degraded and I think we made it pretty clear that the point was that corals themselves, and the factors causing coral mortality, should be the target of reef conservation and management, instead of indirectly addressing what we see as the underlying problem by locally managing herbivores and seaweed.

Isn’t that pretty pretty obvious from the quote from the paper below?

“The current paradigm of reef management and ‘‘resilience’’ is based in large part on the perception that most of the world’s reefs are being overrun by seaweed (Szmant 2001, Precht and Aronson 2006, Knowlton 2008). This belief led to the argument that reef managers should focus primarily on conserving herbivores or water quality (Szmant 2002, Pandolfi et al. 2003, Bellwood et al. 2004). While these are clearly important objectives of management, our analysis suggests that the macroalgae problem has been exaggerated. Overfishing and poor land use practices may trigger widespread coral to macroalgal phase shifts in the future, but to date, the principal form of coral reef degradation has been the loss of reef-building corals, with only limited and localized increases in macroalgae. Therefore, the primary goal for reef managers and policy makers should be the conservation of coral populations, without which the entire system would collapse.”

Several colleagues and reviewers warned us about publishing a “good news” (sort of) story, arguing it would give ammo to skeptics, etc. Frankly, I don’t care. And I doubt many scientists would. If we see conditions improve, we are going to publish that fact. And I really hope we do (see things improve). I am comfortable being an environmental advocate, but I think scientific advocacy should stem from the science, not the other way around.

BTW, who are these people? The Center for the Study of Carbon Dioxide and Global Change mission statement says:

The Center for the Study of Carbon Dioxide and Global Change was created to disseminate factual reports and sound commentary on new developments in the world-wide scientific quest to determine the climatic and biological consequences of the ongoing rise in the air’s CO2 content. It meets this objective through weekly online publication of its CO2 Science magazine, which contains editorials on topics of current concern and mini-reviews of recently published peer-reviewed scientific journal articles, books, and other educational materials. In this endeavor, the Center attempts to separate reality from rhetoric in the emotionally-charged debate that swirls around the subject of carbon dioxide and global change…

Coral bleaching on the radio

Posted on September 21, 2009 by ovehblog

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Here’s an audio segment from Radio New Zealand, where Kathryn Ryan interviews Ove on a range of topics from diving under the Antarctic ice, living 20m underwater for 10 days, coral bleaching and the fate of the Great Barrier Reef:

[audio:https://climateshifts.org/ohgradionz.mp3]

Deep sea coral reefs discovered in Hawaii

Posted on September 9, 2009 by ovehblog

Off the back of the last post, here is an interesting article from the Washington Post on the discovery of deep sea reefs in Hawaii. Deep reefs (‘mesophotic’ coral reefs) exist at the edge of the photic zone (upto 150m depth) and are still dependent on light. These are fascinating ecosystems that to date have been poorly studied:

“We were seeing reefs that no human has ever laid eyes on before,” Randall Kosaki, the research mission’s lead scientist and diver, said Tuesday. “We literally have better maps of the moon than we do of coral reefs in the Hawaiian archipelago.”

Between the area where scuba divers and submersible vehicles have traveled is a “twilight zone” that has long been unexplored, he said. It includes large swaths of coral reefs that can grow up to 400 feet underwater.

“The coral reef habitat goes four times deeper than where we’ve been working prior to this,” Kosaki told reporters.

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(Read M0re)

As a footnote: one of my PhD students, Pim Bongaerts runs an online resource for deep sea coral reefs over at www.mesophotic.org which has some amazing photographs and video footage of research on deep reefs – see here for news and updates.

Screen shot 2009-09-09 at 10.37.54 PM

Belize passes a law to limit fishing of herbivores

Posted on September 4, 2009 by ovehblog

This past May, my lab surveyed 20 reefs in Belize from Bacalar Chico in the north, down to the Sapodilla Keys in the south. It was a fantastic expedition. We had great weather and very calm seas. I was amazed at how wild much of coastal Belize still is. We saw manatees in mangrove creeks and red footed boobies on offshore keys. On some islands you can’t snorkel at night due to the hungry crocs. But I have to admit, the reefs were in pretty bad shape. Mainly from Hurricane Mitch, which struck Belize in 1998, but also from coral disease, bleaching (also in 98) and possibly local stressors.

Glovers_fisher

We were also struck by the intensity of spear fishing, especially on reefs in the central Belizean Barrier Reef, even inside MPAS (but outside of the no-take zones) where fishing is allowed. One morning we surveyed a reef just of the southeastern tip of Glovers Atoll, inside a no-take zone. There was lots of macroalgae and few herbivores, despite the fully protected status. After pulling away from the site, just a few tens of meters outside the no-take zone, we encountered a young spearfisherman in a simple canoe. He was on the forereef, in the open ocean! The mother ship – an equally sketchy looking sailboat – was behind the reef crest. He was very friendly and came over to our boat to show off his catch; nearly 70 kilos of fish by 11 AM! Mostly parrotfish, triggerfish, angelfish and barracuda. The fish are filleted at sea and sold in the fish markets and to local restaurants as “fillet”, i.e., mystery meat.

Pretty depressing. The no-take zones are so small I imagine many fish wander out of them, unknowingly into the line of fire. But the Belizean government just passed a new law designed to protect parrotfish and other key grazers. From a post on the WCS website:

Belize is giving its beleaguered parrotfish, Nassau grouper, and other reef fish a chance to recover from years of overfishing. The national government and minister of agriculture and fisheries signed a sweeping set of new laws to protect the country’s extensive coral reefs…

The first of the new laws will protect parrotfish and other grazers, such as doctor and surgeonfish. These herbivores keep algae growth in check, enabling corals to flourish. In the past, fisherman did not target the grazing fish; rather, they caught mainly snappers and groupers. It was only when these species declined that they turned to the next tier of the food web, and parrotfish began to disappear.

WCS research from Glover’s Reef show that parrotfish are now the most commonly caught fish on this part of the Belize Barrier Reef Reserve System. As a consequence, coral cover has declined. Marine researchers expect that the new laws protecting parrotfish and other grazers will help the corals recover.

The second set of regulations will protect Nassau grouper, which is listed as an endangered species by IUCN’s Red List. The new rules set a minimum and maximum size limit, and require that all Nassau groupers be brought back to the dock whole. Until now, fishermen have generally brought in their catch as fillets, making it difficult to monitor catch rates. All other fish can still be brought in as fillets but must retain a patch of skin so authorities can confirm that they aren’t Nassau grouper.

The third regulation bans spearfishing within marine reserves. Spearfishing is the main method used to catch grazing fish, Nassau grouper, and other groupers and has caused severe declines of these species.

Other aspects of the new laws create “no-take” zones in protected areas. South Water Caye and Sapodilla Cayes marine reserves are now closed to fishing, and the Pelican Cayes—a hotspot for rare sponges and sea squirts—are also off-limits. Though these marine reserves were declared in 1996 and form part of the Belize Barrier Reef Reserve System World Heritage Site, prior to this law, fishing had been permitted there.

We will be tracking the 20 sites to monitor how parrotfish populations change and whether this has cascading effects on corals, algae, etc. Interestingly, the when Melanie McField, a leading coral reef scientist in Belize and the director of the Healthy Reefs for Healthy People initiative showed a video of parrotfish grazing (which you can see here) to the minister of the environment, this is what it took to convince him of the role of these grazers in reef ecosystems. All the science in the world isn’t as powerful as a good You Tube video.

[youtube=http://www.youtube.com/watch?v=4n6pJLC2c0A&w=425&h=344]

Coral reef gloom and doom in the news

Posted on September 2, 2009 by ovehblog

The GBRMPA report Ove covered yesterday and several related reports about the threats to and economic value of coral reefs made international headlines today.

from Reuters:

CANBERRA (Reuters) – Australia’s Great Barrier Reef, the world’s largest living organism, is under grave threat from climate warming and coastal development, and its prospects of survival are “poor,” a major new report found on Wednesday.

“We know that a failure to act on dangerous climate change puts at risk significant places like the Great Barrier Reef and this report confirms the scale of the challenge ahead,” Australia’s Environment Minister Peter Garrett said.

read the full story here

from the BBC:

Current climate targets are not enough to save the world’s coral reefs – and policymakers urgently need to consider the economic benefits they bring.

Those are two of the conclusions from a UN-backed project aiming to quantify the financial costs of damaging nature. Studies suggest that reefs are worth more than $100bn (£60bn) annually, but are already being damaged by rising temperatures and more acidic oceans. The study puts the cost of forest loss at $2-5 trillion annually.

Looking ahead to December’s UN climate conference in Copenhagen, study leader Pavan Sukhdev said it was vital that policymakers realised that safeguarding the natural world was a cost-effective way of protecting societies against the impacts of rising greenhouse gas levels.

There are a number of somewhat notional targets on the table in the run-up to Copenhagen. One, an EU initiative that now has much wider support, is to keep the global average temperature rise since the pre-industrial age within 2C – which according to some analyses means carbon dioxide concentrations in the atmosphere cannot rise above 450 parts per million (ppm). The current level is about 387ppm, and it is rising at about 2ppm each year, although this year’s global recession may bring a blip.

Mr Sukhdev’s team heard evidence from coral scientists that these targets would not be enough to prevent damage to coral reefs around the tropics.

read the full story here

Increasingly bleak future for the Great Barrier Reef?

Posted on September 2, 2009 by ovehblog

Screen shot 2009-09-02 at 10.12.30 PM

The Great Barrier Reef Marine Park Authority released it’s Outlook Report 2009 today (direct link to PDF’s here). The report is a independently peer reviewed assessement of the impacts of climate change, catchment runoff, fishing, coastal development and an array of other impacts on the reef. Alongside the report comes the signing of a new State and Federal Government plan to protect the GBR, tightening regulations for farmers and improving water quality in the GBR lagoon:

“This is about a renewed plan that is underpinned by new and ambitious targets,” Ms Bligh told Parliament today.

“… Through the measures identified in the renewed reef plan we aim by 2013 to halve the runoff of harmful nutrients and pesticides and ensure at least 80 per cent of agricultural enterprises and 50 per cent of grazing enterprises have adopted land management practices that will reduce runoff.”

Ms Bligh said the reef’s resilience had to be built up so it could cope with the effects of climate change, predicted to cause more frequent coral bleaching among other things.

“The poor quality of water running into the reef from catchments has been identified in report after report as a major threat,” she said.

Ms Bligh said two million people visited the coast between Bundaberg and Cairns each year, spending more than $5 million and underpinning 50,000 jobs in the tourism industry alone.

Fisheries contribute a further $290 million annually to the economy, she said.

“We must strike a delicate balance – a balance between making the most of this natural asset and affording it every protection possible,” she said. (Read More)

Signs of resilience and recovery from the coral reefs of Florida

Posted on August 31, 2009 by ovehblog

Here is some good news from the Caribbean – despite a >95% decline in staghorn coral since the 1970’s, there are some signs of resurgence:

Dropping 12 feet below the ocean’s surface less than a mile off Fort Lauderdale’s beach-front towers, a diver might wonder if he or she somehow got magically transported to a remote coral reef in the Caribbean.

Covering the sea bottom is a forest of maize-colored, healthy staghorn coral with grouper, grunts, damselfish and other assorted tropicals swimming all around. If not for the dusky, green water, bits of floating trash and gobs of algae covering some of the surrounding soft corals, the scene could be the Bahamas or Bonaire.

Why is a threatened species of coral thriving near urban Broward County? (Read More)

Copenhagen flop: skeptic arguments 101

Posted on August 31, 2009 by ovehblog

Back at the start of the decade, Coral List (a list-serv email discussion run by NOAA) had some great topics up for debate amongst the coral reef scientific community. These days Coral List continues to make for a fantastic place for information and discussion, yet the intense debate of old seems increasingly thin on the ground. Every once in a while though, there are some pretty fantastic debates, like the recent ‘Copehagen Flop’. The original post debated the relevance of an article in a Danish newspaper (“Climate summit flop feared“) citing multiple hotel reservation cancellations in Copenhagen as evidence of a poor showing for the upcoming UN climate change conference in December 2009.

After this topic was debated a while, another post came up questioning the rational of the Copenhagen as temperatures have been dropping whilst CO2 is rising, sunspots are overdue, climate change is a growth industry, and how geologists know better. Enter John Bruno, who i’m guessing is long tired of the same old ‘skeptic’ arguments. See below for the entire article in it’s entirety – it’s one of the most concise and well written critiques i’ve read in a while. Posting from Brisbane Australia, where it’s pretty freaking hot too (last week we hit an August record of 35.4°c – in the middle of our winter).

From: John Bruno <jbruno@unc.edu>
Date: 29 August 2009 9:48:16 AM
To: coral-list@coral.aoml.noaa.go
Subject: Copenhagen flop: skeptic arguments 101

Climate change skeptics have a basket of well-worn arguments for why humans are not in fact changing the earth’s climate. Gene deploys many in his wonderfully cranky and cynical post. I have found it entertaining and even useful (when arguing with skeptics) to become familiar with the most common skeptic arguments. Most skeptics use the same pool of 3-5, although the most popular change over time. The fantastic web site SketicalScience tracks, ranks, outlines and debunks the most popular:

http://www.skepticalscience.com/argument.php

Also see: http://www.grist.org/article/series/skeptics/

Currently, the most popular argument is the well-debunked “it’s the sun stupid” argument, which Gene includes in his post. Read up on this argument at these links:

http://www.grist.org/article/its-the-sun-stupid/

http://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm

http://www.realclimate.org/index.php/archives/2005/07/the-lure-of-solar-forcing/

The second most popular skeptic argument is that “climate changed before”. I am pretty sure you don’t have to have a PhD in geology to be aware of the fact that the earth’s climate fluctuates. My kids learned about ice ages and geological eras in kindergarten. And the reality of past natural climatic fluctuation in no way refutes evidence that current trends are strongly influenced by human activities. In fact quite the opposite; the relative speed of the current changes compared to the many past cycles suggest something is different about this cycle. Also see: http://www.grist.org/article/climate-is-always-changing/

Gene alludes to the third most popular, “there is no consensus” argument: http://www.skepticalscience.com/global-warming-scientific-consensus.htm

And also the very popular (currently at position #4) “the earth is actually cooling!” argument. This is of course nonsense that is is based on cherry-picking small periods in the longer-term climate record. The most popular this year is choosing 1998 (by chance? – I doubt it) as the beginning and examining how global temperature has change since then. Indeed, by some (but not all) measures there is a slight cooling since 1998. But such cherry-picking is (to anyone trained in science) a silly and disingenuous way to test for trends in the longer term climate record. We have blogged about and made fun of this skeptic argument pretty extensively at ClimateShifts:

https://climateshifts.org/?p=937

https://climateshifts.org/?p=1000

Also see:

http://www.woodfortrees.org/notes.php#trends

http://www.skepticalscience.com/global-warming-stopped-in-1998.htm

Gene also works in the “models are unreliable” argument (the 5th most popular)

http://www.skepticalscience.com/climate-models.htm

http://www.grist.org/article/climate-models-are-unproven/

and the “global warming stopped in 1998” argument (currently ranked in 8th place), which is related to the “the earth is actually cooling!” argument

http://www.skepticalscience.com/global-warming-stopped-in-1998.htm

and very frequently tied in with the “it’s freaking cold!” (15th place) argument

http://www.skepticalscience.com/global-warming-cold-weather.htm

AKA “it’s cold today in Wagga Wagga”: http://www.grist.org/article/its-cold-today-in-wagga-wagga/, where Gene, like so many skeptics, confuses local and short term weather for climate.

Additionally, as the National Climatic Data Center recently reported, ocean temperature this July has been the hottest in the last 130 years of record keeping: https://climateshifts.org/?p=2654

And as I recently blogged about, a new paper published in Geophysical Research Letters (Easterling and Wehner 2009) demonstrates that short term periods of no-trend or even cooling (nested within longer term warming) are in fact predicted by Global Climate Models; https://climateshifts.org/?p=2029

Finally, Gene takes a slightly new angle on the well-worn “climate changed before” argument. Most skeptics are not geologists; most skeptics (including about half of all adult Americans) are not scientists of any type. Moreover, most geologists are not skeptics as is evidenced by the various briefing articles and position pieces published by the American Geophysical Union, e.g., http://www.agu.org/outreach/science_policy/positions/climate_change2008.shtml

titled “Human Impacts on Climate” which begins “The Earth’s climate is now clearly out of balance and is warming. Many components of the climate system—including the temperatures of the atmosphere, land and ocean, the extent of sea ice and mountain glaciers, the sea level, the distribution of precipitation, and the length of seasons—are now changing at rates and in patterns that are not natural and are best explained by the increased atmospheric abundances of greenhouse gases and aerosols generated by human activity during the 20th century.”

Cheers from Chapel Hill, where it is freaking hot!

JB

John F. Bruno, Ph.D.
Associate Professor
Department of Marine Science
The University of North Carolina at Chapel Hill
Chapel Hill, NC 27599-330
jbruno@unc.edu
www.brunolab.net
www.climateshifts.org

Update: I thought to better put this in context, I’d add the post I was responding too. Gene Shinn is a well-known carbonate geologist. (John Bruno)

I read all the responses about the Copenhagen flop on the list
with great interest and feel they skirt the underlying issue. I serve
on a large global climate change committee and am exposed to the
research and opinions from both sides of the issue several times each
day.  Most of the skeptics are geologists that look to the geologic
record for guidance. The warmers look to mathematical models that
project far into the future. Those on the pro warming side of the
issue often work for companies, government agencies, or Universities
involved (think paychecks) in CO2 sequestration projects or involved
in the cap and trade business. The other side, mainly geologists, are
well aware of former climate changes  before humans arrived on the
scene. The public does not know who to believe.
     I suspect the real reason attendance will remain low in
Copenhagen (unless the climate starts warming again) Is they are
skeptical, or unsure, of what the climate will do in the future.
Temperature has been dropping (abundant low temperature records were
set in July) and many researchers have shown temperature has overall
been  flat since 2000.  At the same time temperatures have been
dropping (over the past two years)  CO2 has continued to rise!  It is
hard not to  notice that temperatures have fallen. Just read the news
papers. I suspect this observation  has not gone unnoticed by a
growing body of scientists,  politicians, and investors.  Investors
are no dummies.  Clearly climate change is a huge growth industry.
Does anyone not believe that many of the attendees will be there
looking for a way to make money? I doubt they will be there because
they fear the earth will burn up! Have coral-listers really looked
into the money already being made on cap and trade and the sale of
pollution credits? The next few years will be the proof of the
pudding and Sunspot cycle 24 is still overdue. Gene PS: There is a
Foundation  cranking up for the "preservation of CO2." It's all about
increasing agriculture production. They will be looking for your tax
exempt contributions.  Ain't this a great country or what!

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
Tel 727 553-1158

Coral reefs, climate change, coral bleaching – OHG on Catalyst

Posted on August 28, 2009 by ovehblog

“This is not a political debate, it’s gone way beyond simply debating the science of whether or not we should act”

Click on the link below to see Ove on the Australian television program ABC Catalyst discussing global climate change and the onset of mass coral bleaching in the late 90’s.

Climate Shifts

Life in a rapidly changing climate

Category Archives: Coral Reefs