Reefs in trouble – The real root cause

Yellow band disease

Dr. Stephen Jameson recently published a provocative essay in the Marine Pollution Bulletin that has stimulated considerable debate among reef scientists and conservationists, especially on the coral list server.  His goal was to drill down to the ultimate social/political cause of reef decline, beneath the  proximate environmental causes reef scientists study:

The real root cause of coral reef decline is not carbon dioxide emissions, rising sea surface temperatures, ocean acidification, coral disease, over fishing, destructive fishing techniques, eutrophication, sedimentation, sewage, herbicides, pesticides, African dust, increasing human populations or any of the other individual or synergistic combinations of stressors affecting coral reefs locally,regionally or globally – these are only symptoms of much bigger and more profound problem.  At its core, the real root cause of coral reef decline, when objectively looking at the evidence, seems to be attributable to innate human species behavior characteristics determined by how we are genetically hard-wired.

Dr. Jameson said, “I wrote it in response to the International Year of the Reef/Science Magazine issue “Reefs in Trouble” (14 Dec 2007) that, in my opinion, missed a golden opportunity to address the “real” root cause of “Reefs in Trouble””.  And what he is really trying to get at is whether large groups of humans are capable of cooperatively managing a complex system like a reef.  “Do we really have the capability, when operating as a very large group such as a nation or group of nations, to govern ourselves effectively and live sustainably with our environment?”  There is lots of evidence that we can do so when in small, communal groups, but why when we organize as nations do things seem to go awry?

Our every day experience in the United States (and in many other countries) informs us that the state of our governance, where wealthy business and special interests use campaign financing, lobbying, and media control to manipulate government policy and public perceptions is not a viable system for conserving coral reefs or for sustainable living because it is predicated on the fact that; ‘‘He who owns the political trump card wins”

It is a great system for creating corporate profit and socializing expense at global cost, but it does not produce clean air and water in natural environments or enhance biodiversity.

Stephen is also asking: can a social, cultural community consciousness evolve into a global consciousness? There are several layers to the answer.  As he argues, there may be genetically or socially based behavioral limitations that have and will preclude the development of a new form of global altruism.  There are also complex competing forces that have designed a governance system incompatible with the conservation of species and ecosystems half way around the world.  But I think a very deep perception gap is another key problem.  Even in wealthy nations, where we have the luxury of worrying about such matters, I am struck by how few people recognize that their actions can affect other people in far away nations.  Many people I talk to in the US are aware of climate change and the decline of coral reefs, but have a hard time comprehending that their choices and behaviors could actually be causing problems for people and corals in the south Pacific.  Making people, especially policy makers, aware of the striking effects we are having on all the world’s oceans, including ocean chemistry and temperature, will be a critical battle in the broader campaign to address the real root cause.


Jameson SC (2008) Guest editorial: Reefs in trouble ­ the real root cause. Marine Pollution Bulletin 56(9):1513-1514

Scientists urge Prime Minister Kevin Rudd to crack down on climate change issues

The Age is reporting on an open letter to the Australian Prime Minister Keven Rudd, urging the PM to make strong cuts in Australia’s greenhouse gas emissions by 2020. The letter, written by myself and 15 other Austalian scientists who contributed to the IPCC report, was released on the eve of the final report by the Garnaut review on climate change. In essence, we disagree with the recent advice by Professor Garnaut to make a slower start in cutting emissions (Targets and Trajectories – a 10% reduction by 2020), and strongly advocate the PM to reduce emissions by at least 25% bellow 1990 levels by 2020:

“As a group of Australia’s leading climate change scientists, we urge you to adopt this target as a minimum requirement for Australia’s contribution to an effective global climate agreement,” the letter states.

“Failure of the world to act now will leave Australians with a legacy of economic, environmental, social and health costs that will dwarf the scale of national investment required to address this fundamental problem”.

The scientists who signed the letter are Australia’s world-recognised experts on climate change, including Dr John Church, a leading authority on sea-level rise who recently stepped down as chairman of the joint scientific committee of the World Climate Research Program. Dr Church is also a senior CSIRO researcher, but he and other CSIRO scientists signed the letter as individuals.

Also among the signatories are Dr Roger Jones, from CSIRO, who is currently advising the federal Treasury and Professor Garnaut’s climate change review; Professors Nathan Bindoff and David Karoly, who worked on the most recent IPCC reports; Professor Tony McMichael from the Australian National University, who advised the IPCC on the human health impacts of climate change; Professor Matthew England, joint director of the Climate Change Research Centre at the University of New South Wales; and Professor Ove Hoegh-Guldberg, an expert on climate change and the Great Barrier Reef.

On the back of the report is a recent poll by the Lowy institute, which is quite an intriguing read. Whilst the overall message is a positive one in that Australians want action on climate change, the feeling is that it cannot come at a cost to jobs or at a financial cost. Out of the 1001 people, 19% surveyed said they would be willing to pay >$21 per month ontop of their electricity bill to help solve climate change, and 20% would pay between $11-20. In contrast, 32% would be willing to pay between $1-10 per month, whilst 32% of people surveyed were not prepared to pay anything at all.

Interestingly, 64% of responants believed that the Kyoto Protocol hasn’t solved the issue of climate change but was “a step in the right direction”, yet 26% believed it was “purely symbolic”. On the bright side, if this poll is a genuine reflection of Australian attitudes, 73% would prefer Barack Obama to become the next president of the United States, whilst John McCain recieved only a 16% response.

Never Mind the Mohawk, Here’s the Mary River Turtle

Sorry for the bad pun… These great images were captured by photographer Chris van Wyk in Queensland, Australia (the green ‘mohawk’ effect, remniscent of the British subculture of the early 1980’s is actually an ephiphytic turf algae growing on the shell and head of the turtle). The Mary River turtle (Elusor macrurus) is considered “endangered” under the Environment Protection and Biodiversity Conservation Act in Queensland, and is geographically limited to shallow slow moving waters in the Mary River and it’s tributaries. Not only is it one of Australia’s largest species of turtles (>50cm), it is the sole species in it’s genus, representing an incredibly old lineage of turtles that has since disappeared from Australia’s evolutionary history. As Queensland has been in one of the longest draughts in over a century, the Queensland government is intending on creating a dam in the Mary River, impacting upon the habitat of the Mary River turtle and a host of other rare and endangered native species such as the Queensland lungfish and the Murray River cod.

Global CO2 emissions exceed IPCC worst case scenario

A comprehensive report released today by the Global Carbon Project contains the grim news that global CO2 emissions are exceeding the most pessimistic IPCC emissions scenario. The annual mean growth of atmospheric CO2 increased from 2.0 ppm (parts per million) during the first half of the decade and from 1.8 ppm in 2006,  to 2.2 ppm in 2007.  This increase in the growth of emissions makes IPCC stabilization scenarios of 450 ppm – 650 ppm doubtful.

Annual mean growth rates of atmospheric CO2 concentration.

The report “Carbon budget and trends 2007” is a sobering synthetic analysis of the world’s carbon budget, including the sources and sinks of CO2 parsed by nation, continent, human activity and ecosystem.

Despite the increasing international sense of urgency, the growth rate of emissions continued to speed up, bringing the atmospheric CO2 concentration to 383 parts per million (ppm) in 2007.  Anthropogenic CO2 emissions have been growing about four times faster since 2000 than during the previous decade, despite efforts to curb emissions in a number of Kyoto Protocol signatory countries.

Dr. Pep Canadell, executive director of the Global Carbon Project said “This new update of thecarbon budget shows the acceleration of both CO2 emissions and atmospheric accumulationare unprecedented and most astonishing during a decade of intense international developments to address climate change.”

Fossil Fuel Emissions: Actual vs. IPCC Scenarios

Some of the report highlights are excerpted below:

Atmospheric CO2 growth: Annual mean growth rate of atmospheric CO2 was 2.2 ppm per year in 2007 (up from 1.8 ppm in 2006), and above the 2.0 ppm average for the period 2000-2007. The average annual mean growth rate for the previous 20 years was about 1.5 ppm per year. This increase brought the atmospheric CO2 concentration to 383 ppm in 2007, 37% above the concentration at the start of the industrial revolution (about 280 ppm in 1750).  The present concentration is the highest during the last 650,000 years and probably during the last 20 million years. [ppm =  parts per million].

Regional fossil fuel emissions
The biggest increase in emissions has taken place in developing countries, largely in China and India, while developed countries have been growing slowly. The largest regional shift was that China passed the U.S. in 2006 to become the largest CO2 emitter, and India will soon overtake Russia to become the third largest emitter. Currently, more than half of the global emissions come from less developed countries. From a historical perspective, developing countries with 80% of the world’s population still account for only 20% of the cumulative emissions since 1751; the poorest countries in the world, with 800 million people, have contributed less than 1% of these cumulative emissions.

Conclusions: Anthropogenic CO2 emissions have been growing about four times faster since 2000 than during the previous decade, and despite efforts to curb emissions in a number of countries which are signatories of the Kyoto Protocol. Emissions from the combustion of fossil fuel and land use change reached the mark of 10 billion tones of carbon in 2007. Natural CO2 sinks are growing, but more slowly than atmospheric CO2, which has been growing at 2 ppm per year since 2000. This is 33% faster than during the previous 20 years. All of these changes characterize a carbon cycle that is generating stronger climate forcing and sooner than expected.


Global Carbon Project (2008) Carbon budget and trends 2007, [, 26 September 2008]”

MPAs and climate change II: study finds no-take reserves do not increase reef resilience

PI Nick Graham surveying a high coral cover reef.

PI Nick Graham surveying a high coral cover reef.

Some coral reefs scientists have argued (and prayed) that marine reserves (no-take MPAs) could limit the impacts of climate change on populations of reef-building corals.  The idea is that by maintaining healthy food webs and herbivore populations, reef managers can prevent seaweed blooms that can kill juvenile corals.  Restricting fishing would thus increase reef resilience (which ecologists define as the return rate of an ecological system to its baseline state following a disturbance).  Unfortunately, a new study tempers such wishful thinking.

The study (Graham et al. 2008 published on August 27 in the open access journal PloS One) indicates that marine reserves have no effect on coral resilience to ocean warming.

Approximately 45% of coral cover in the Indian Ocean was lost in 1998 due to temperature-related coral bleaching.  To compare coral loss within and outside of reserves, the team resurveyed 66 reefs in the Indian Ocean that had originally been surveyed before the 1998 mass bleaching event.  The surveyed sites included reefs within nine reserves in four countries.

The results indicated that “A greater proportion of [marine reserves] (71%) than fished (42%) locations showed significant declines in coral cover over the study period. There was no evidence to suggest the percent change in coral cover differed between [marine reserves] and fished areas, and in some cases declines were significantly greater in [marine reserves]”

This is an important study in coral reef ecology.  As a believer in Macroecology and a long-time disciple of James Brown (the desert ecologist, not the King of Funk) I think such a regional-scale, carefully implemented approach could be used to answer many other key questions in reef ecology.  Having read hundreds of monitoring studies while building a database of >10,000 reef surveys, I can attest that there are few targeted macroecological reef studies of this scope.  There are some monitoring programs this large.  But few studies of this scale are designed and implemented to answer a specific question.  Although the macroecological approach is rarely employed (due to obvious financial and logistical constraints), it certainly isn’t new.  Terry Hughes (Hughes 1994 Science) applied it by resurveying nine reefs on the north coast of Jamaica after a variety of disturbances wiped out corals and enabled macroalgae to become the dominant benthic organism.  Even earlier, Endean and Stablum surveyed dozens of reefs across the GBR in the late 1960s and early 1970s to assess the impact of and recovery from a regional crown-of-thorns starfish outbreak.

I imagine critics of Graham et al. 2008 and it’s implications could argue that many or most tropical marine reserves are not well-managed and that they might increase resilience if enforced.  This would be a fair point, but given the political and socio-economic realities of the region, poaching might be difficult or impossible to eliminate.  So to paraphrase Donald Rumsfeld, we might just have to conserve reefs with the marine reserves we have, not the marine reserves we want.

Change in coral cover at sites across the western Indian Ocean

Change in coral cover at sites across the western Indian Ocean. Green and red symbols represent increases and decreases in coral cover respectively. Symbols with solid borders are sites in marine reserves. Data represent 66 sites across the region. Numbers in key (size of bubble) are percent changes between mid 1990s and 2005.

“Carr targets PM on logging”

Sydney Morning Herald, 22nd September, 2008

THE fraught political battle over logging in native forests is set to be re-ignited with the former Labor premier Bob Carr writing to the Prime Minister and senior ministers arguing that protecting the forests is “fundamental” to fighting climate change.

In a letter to Mr Rudd, his Climate Change Minister, Penny Wong, the Environment Minister, Peter Garrett, and the Forestry Minister, Tony Burke, Mr Carr has joined leading conservationists who want to transform state and federal forest policies in NSW, Victoria and Tasmania to protect older forests and previously logged forests.

Citing research from the Australian National University that says Australia’s eucalypt forests could hold about three times more carbon than previously thought, Mr Carr argues that rethinking forest policy is vital if Australia is going to cut its greenhouse gas emissions. Keeping carbon dioxide locked up, or “sequestrated”, in the forests will not only slow Australia’s rising greenhouse gas emissions but prevent the extinction of native plants and animals, the letter argues.

“Protecting our existing native forests and other vegetation is therefore fundamental to meeting any emissions reduction target. In addition, previously logged natural forests, if allowed to continue growing, will realise their carbon sequestration potential,” Mr Carr writes in a letter also signed by Peggy Figgis, the vice- chairwoman of the International Union for the Conservation of Nature, and Rick Humphries, from Greening Australia.

Continue reading

Australian coral reefs in the news: past, present, future

“Ancient reef found in outback” (Courier News, September 22nd, 2008)

AN ancient underwater reef discovered in Australia’s outback could unlock the secrets of the world’s climate change history, scientists said.

Located in South Australia’s Flinders Ranges, the 650-million-year-old reef existed during a period of tropical climate between two major ice age events, scientist Jonathan Giddings said in a media release today.

(Link to full story)

Explorers Find Hundreds Of Undescribed Corals (Science Daily, 19th September, 2008)

Hundreds of new kinds of animal species surprised international researchers systematically exploring waters off two islands on the Great Barrier Reef and a reef off northwestern Australia — waters long familiar to divers.

The expeditions, affiliated with the global Census of Marine Life, help mark the International Year of the Reef and included the first systematic scientific inventory of spectacular soft corals, named octocorals for the eight tentacles that fringe each polyp.

(Link to full story)

Distance no barrier to reef care (The Australian, September 23rd, 2008)

THE Australian Institute of Marine Science has begun using one of the world’s first reef-based internet protocol networks to monitor the impact of destructive forces on the Great Barrier Reef.

Using waterproof Next G modems, adaptive sensor equipment and solar-powered buoys to float the devices, AIMS has installed two wireless IP networks that can transmit data in real time up to 100km offshore.

“We’ve been hit by a number of coral-bleaching events over the past 10 years but until now we’ve had no way to monitor the causes unless we’ve been there in person,” Great Barrier Reef Observing System project manager Scott Bainbridge said.

(Link to full story)

Corals prove to be “nonconformist”

An article published in PLoS One  has huge implications for almost everything we do in our research on corals.  In summary, using an array of genetic markers, a highly respected group of leading scientists including Fukami, Chen, Knowlton and others have shown that whilst Scleractinia (the stony corals) have a single origin in evolution, to date we have lumped many species and genera into families incorrectly, at least partly due to the traditional system of classification .  This finding has the interesting implication that morphological features (at the heart of coral taxonomy) may have been much more plastic in time than we have appreciated.  Such findings make sense given how variable the skeletal structure of corals is in response to the environmental circumstances the coral is growing in.




Fukami et al (2008) Mitochondrial and Nuclear Genes Suggest that Stony Corals Are Monophyletic but Most Families of Stony Corals Are Not (Order Scleractinia, Class Anthozoa, Phylum Cnidaria). PLoS ONE 3(9): doi:10.1371/journal.pone.0003222

Modern hard corals (Class Hexacorallia; Order Scleractinia) are widely studied because of their fundamental role in reef building and their superb fossil record extending back to the Triassic. Nevertheless, interpretations of their evolutionary relationships have been in flux for over a decade. Recent analyses undermine the legitimacy of traditional suborders, families and genera, and suggest that a non-skeletal sister clade (Order Corallimorpharia) might be imbedded within the stony corals. However, these studies either sampled a relatively limited array of taxa or assembled trees from heterogeneous data sets. Here we provide a more comprehensive analysis of Scleractinia (127 species, 75 genera, 17 families) and various outgroups, based on two mitochondrial genes (cytochrome oxidase I, cytochrome b), with analyses of nuclear genes (ß-tubulin, ribosomal DNA) of a subset of taxa to test unexpected relationships. Eleven of 16 families were found to be polyphyletic. Strikingly, over one third of all families as conventionally defined contain representatives from the highly divergent “robust” and “complex” clades. However, the recent suggestion that corallimorpharians are true corals that have lost their skeletons was not upheld. Relationships were supported not only by mitochondrial and nuclear genes, but also often by morphological characters which had been ignored or never noted previously. The concordance of molecular characters and more carefully examined morphological characters suggests a future of greater taxonomic stability, as well as the potential to trace the evolutionary history of this ecologically important group using fossils.

Kingman Atoll, MPAs and climate change

A by Zafer Kizilkaya, B by Jennifer Smith.

Top predators and coral cover on Kingman Atoll. Photo credits: A by Zafer Kizilkaya, B by Jennifer Smith

The key drivers of anthropogenic coral mortality and loss are nearly all regional- to global-scale stressors, including ocean warming and acidification, and coral predator and disease outbreaks.  Yet some scientists hope to mitigate these threats locally through fisheries regulations, such as the implementation of Marine Protected Area (MPAs) designed to increase “reef resilience”.  By limiting or preventing fishing and other extractive activities, MPAs have been relatively successful in restoring populations of overharvested fish and invertebrates.  MPAs could also, in theory, benefit corals by restoring coral reef food webs and more directly by preventing destructive fishing practices and anchor damage.  But can MPAs mitigate the effects of climate change?

In a paper recently published in the open access journal PloS One, Sandin et al. (2008), argue that the answer is “Yes”.  Co-author Nancy Knowlton stated “These remote healthy reefs clearly show that local protection can make reefs resilient to the impacts of global change”.  And lead author Stuart Sandin said “the healthier reefs showed the capacity to recover from climate change events…when the ecosystem structure is intact, the corals appear to bounce back better from previous warm water events that have killed coral.”

The study described a multifacited survey of four reefs in the northern Line Islands.  Reefs differed considerably along a gradient of proximity to people; more remote reefs had more large predators, fewer herbivores and higher coral cover.  The positive relationship between coral cover and predator biomass (in the non-statistical sense that the reef with the most fish had the most coral) led to the conclusion that “protection from overfishing and pollution appears to increase the resilience of reef ecosystems to the effects of global warming.”

If true this would be a remarkable finding.  For a variety of other reasons we clearly need to get a handle on greenhouse emissions and climate change.  But until we do, perhaps MPAs could preserve reef ecosystems, or at least minimize reef degradation.  However, nearly all of my colleagues that I have spoken to about this study and the potential of MPAs remain skeptical, mainly because MPAs cannot directly regulate or eliminate the primary culprits of anthropogenic coral loss.

In an op-ed describing the impact of the new the Papahanaumokuakea Marine National Monument in the Northwest Hawaiian Islands, Enric Sala (the Line Islands expedition leader) argued, “A national monument can protect against the decimation of sharks, groupers and jacks by fishing, but it cannot protect against global threats to marine life such as global warming and marine debris…Increased temperatures and currents do not respect national monument boundaries.”  William Precht, a coral reef geologist and restoration specialist for the Florida Keys National Marine Sanctuary, added “Data from throughout the Caribbean and western Atlantic indicate that no form of local stewardship or management could have protected coral populations from their major sources of mortality (pandemic diseases, regional coral bleaching, and severe storms) or changed the overall trajectory of coral loss observed during the past few decades.”

The Line Islands study could have been a nice natural experiment, testing the efficacy of MPAs in mitigating climate change, had nature cooperated.  Unfortunately, it didn’t, and the temperature stress gradient and the fishing intensity gradient were positively correlated, confounding the test and any interpretation of the mechanisms underlying the observed variability in coral cover.  The reef with virtually no fishing and the most predators (Kingman) also has not experienced any significant warming or warm periods over the last decade.  Was the high coral cover caused by the lack of fishing or the lack of bleaching?  And could the high coral cover be in part responsible for the plentiful fish populations on Kingman reef?  Further study and a second expedition seem warranted.  I hereby place my name on the top of the volunteer list.

In my view, the strength and novel contribution of the study is the comprehensive assessment of a pristine marine ecosystem.  As a community ecologist who is far more interested in food webs than microbes, the thing that I found fascinating about the Sandin et al. study was the inverted trophic pyramid at Kingman Atoll; the biomass of top predators was far greater than that of their prey.  Herbivorous fish were scarce and frightened, which makes me wonder why macroalgal cover was so low.  I suspect this was due to grazing by urchins, which were most abundant at Kingman, probably because their predators were being suppressed by higher level consumers.  Despite it’s limitations, the Sandin et al. study demonstrates a powerful macroecologial approach that could be used to test a key hypothesis in coral reef ecology and conservation.

High coral cover and diversity at Magnetic Island, Great Barrier Reef


Here are some underwater photographs taken at a recent field trip at Magnetic Island, inshore Great Barrier Reef. These reefs are usually highly turbid, based 8km away from the Townsville shoreline.  I’m often suprised at the diversity and high cover of some of these inshore reefs, and the visibility at Magnetic this day finally lifted above it’s usual "pea-soup" consistency to get some good photographs.