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Kingman Atoll, MPAs and climate change

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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

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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.

 

A changing climate of opinion? The Economist reports on geoscale engineering to avert dangerous climate change

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The Economist, September 4th 2008

Some scientists think climate change needs a more radical approach. As well as trying to curb greenhouse-gas emissions, they have plans to re-engineer the Earth. There is a branch of science fiction that looks at the Earth’s neighbours, Mars and Venus, and asks how they might be made habitable. The answer is planetary engineering. The Venusian atmosphere is too thick. It creates a large greenhouse effect and cooks a planet that is, in any case, closer to the sun than the Earth is to even higher temperatures than it would otherwise experience. Mars suffers from the opposite fault. A planet more distant from the sun than Earth is also has an atmosphere too thin to trap what little of the sun’s heat is available. So, fiddle with the atmospheres of these neighbours and you open new frontiers for human settlement and far-fetched story lines.

It is an intriguing idea. It may even come to pass, though probably not in the lifetime of anyone now reading such stories. But what is more worrying—and more real—is the idea that such planetary engineering may be needed to make the Earth itself habitable by humanity, and that it may be needed in the near future. Reality has a way of trumping art, and human-induced climate change is very real indeed. So real that some people are asking whether science fiction should now be converted into science fact.

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Melting Artic ice acts as a CO2 sink, whilst Antarctic wintertime ice is on the increase

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"Antarctic sea ice increases despite warming" (New Scientist, 12 September 2008)

The amount of sea ice around Antarctica has grown in recent Septembers in what could be an unusual side-effect of global warming, experts say.

In the southern hemisphere winter, when emperor penguins huddle together against the biting cold, ice on the sea around Antarctica has been increasing since the late 1970s, perhaps because climate change means shifts in winds, sea currents or snowfall.

At the other end of the planet, Arctic sea ice is now close to matching a September 2007 record low at the tail end of the northern summer, in a threat to the hunting lifestyles of indigenous peoples and creatures such as polar bears.

"The Antarctic wintertime ice extent increased…at a rate of 0.6% per decade" from 1979 to 2006, says Donald Cavalieri, a senior research scientist at the NASA Goddard Space Flight Center in Maryland.

At 19 million square kilometres, it is still slightly below records from the early 1970s of 20 million, he says. Since 1979 however, the average year-round ice extent has risen too.

(link to full article)

 

"Melting ice caps could suck carbon from atmosphere" (New Scientist, 10 September 2008)

It’s not often that disappearing Arctic ice is presented as good news for the planet. Yet new research suggests that as the northern polar cap melts, it could lift the lid off a new carbon sink capable of soaking up carbon dioxide.

The findings, from two separate research groups, raise the possibility – albeit a remote one – of weakening the greenhouse effect. The researchers say the process of carbon sequestration is already underway. Even so, the new carbon sink is unlikely to make a significant dent in the huge amounts of CO2 pumped into the atmosphere by industrial activities.

Kevin Arrigo and colleagues at Stanford University studied satellite data collected between 1998 and 2007 to see how sea surface temperatures and the quantities of sea ice and phytoplankton had changed during that time.

Phytoplankton produce chlorophyll to obtain energy from the sun and assimilate CO2, and so increased phytoplankton productivity would remove more carbon from the atmosphere.

"We found that as sea ice diminishes, annual productivity goes up," says Arrigo. Satellite remote sensing measures the amount of chlorophyll in surface waters, and so provides an estimate of ocean productivity.

(Link to full article)

” Climate change isn’t something to be believed or disbelieved”

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The Guardian, September 4th 2008 (by Martin Parry, lead author of the 2007 assessment of impacts and adaptation by the IPCC)

"The media love a good argument, and what better than to pitch polemicists against each other from opposite ends of the spectrum? Thus we are given Björn Lomborg v Oliver Tickell in a so-called "climate debate" (Tickell’s apocalyptic view obscures the solutions; Lomborg’s stats won’t mean much underwater, August 21). Regrettably, we learned from this only that sensible solutions are unlikely to flow from entrenched and extreme positions. Most scientists are amazed and alarmed that the issue of climate change should be treated as an article of faith – something either to be believed or disbelieved – rather than a problem surrounded by a lot of uncertainty. What we got from these two was very misleading.

Lomborg claimed: "A lead economist of the IPCC [Intergovernmental Panel on Climate Change] did a survey of all the problems and all the benefits accruing from a temperature rise over this century of about approximately 4C. The bottom line is that benefits right now outweigh the costs." There have been a few studies of the current effects of climate change (for example, on ice shelf and glacier retreat, and on plants and animals) and the IPCC has concluded these are happening faster than had been expected. But despite what Lomborg says there has been no useful assessment of whether these are beneficial or not, because aggregation of effects involves meaningless trade-offs such as comparing the destruction of Inuit communities with the benefits of ice-freed shipping lanes.

Lomborg believes that 4C of global warming "will not be a challenge to our civilisation" and derides Tickell, whom he quotes as stating that warming of this amount would bring "the beginning of the extinction of the human race". Both of these are heroic conclusions, since there has been no study of the limits to our adaptive capacity. The climate change issue has never been about whether we can survive or not, but keeping damages and costs to a tolerable level. The IPCC concluded in 2007 that we risk billions more people being short of water due to climate change, and hundreds of millions at risk of flooding and hunger. That is a lot of suffering, but not the end of civilisation.

There is a strong emerging view, proposed by the IPCC in its latest assessment in 2007, that a careful mixture of mitigation (reducing emissions) and adaptation will be necessary to meet the challenge of climate change. And this is broadly accepted by governments now striving for agreement by the end of next year. The polarised views of both Tickell and Lomborg miss this completely. We know we cannot avoid some serious climate change (our vacillation over the past 10 years has put paid to that), but we can avoid the worst of it. At a minimum we will have to adapt to about 2C of warming. The choice still available to us is whether we should try to avoid more than this amount of warming. Common sense suggests we should, since we do not really know what impacts the future holds, and we risk repeating the mistake of the movie producer Lew Grade who, looking back on the mounting losses of his film Raise the Titanic, concluded: "It would have been cheaper to lower the Atlantic."

“Cut greenhouse gases to save coral reefs: scientists”

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Reuters, 27th August 2008

To keep coral reefs from being eaten away by increasingly acidic oceans, humans need to limit the amount of climate-warming greenhouse gases in the atmosphere, a panel of marine scientists said on Wednesday.

"The most logical and critical action to address the impacts of ocean acidification on coral reefs is to stabilize atmospheric carbon dioxide concentration," the scientists said in a document called the Honolulu Declaration, for release at a U.S. conference on coral reefs in Hawaii.

Ocean acidification is another threat to corals caused by global warming, along with rising sea levels, higher sea surface temperatures and coral bleaching, the scientists said.

Coral reefs are a "sentinel ecosystem," a sign that the environment is changing, said one of the experts, Billy Causey of the U.S. National Marine Sanctuary Program.

"Although ocean acidification is affecting the health of our oceans, the same thing — increased carbon dioxide in the atmosphere — is going to in fact be affecting terrestrial environments also," Causey said by telephone from Hawaii.

Coral reefs offer economic and environmental benefits to millions of people, including coastal protection from waves and storms and as sources of food, pharmaceuticals, jobs and revenue, the declaration said.

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“Shipwrecks Wreak Havoc on Coral Reefs”

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ScienceNow News, 21st August

Warming seas and ocean acidification aren’t the only hazards facing the world’s coral reefs. A new study suggests that the communities can be thrown quickly and seriously out of balance by the iron from sunken ships. Scientists hope the findings will encourage the prompt removal of derelicts before they can damage the fragile ecosystems.

The problem with shipwrecks appears to be a particularly aggressive reef-dwelling creature called Rhodactis howesii, a type of sea anemone. When nutrients are abundant and there are no predators, R. howesii thrives. Unfortunately, it also eats coral, threatening the foundation of the ecosystem.

Several previous studies have linked shipwrecks and reef degradation, but researchers in Hawaii decided to measure the effect in detail. They surveyed a coral reef off Palmyra, an isolated atoll in the middle of the Pacific Ocean. There they found high densities of R. howesii near a longline fishing boat that sank in 1991. Those densities steadily declined with distance from the wreck; and within about 100 meters, they dropped to zero–with a few exceptions. The exceptions, the team reports today in PLoS ONE, involve navigation buoys installed on the atoll in 2001.

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Researchers find large patch of algal reefs

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Taiwan Journal, 22nd August 2008

Researchers from Academia Sinicia have uncovered the largest algal reef in eastern Taiwan along the coast of Shanyuan Bay in Taitung County.

"It’s quite surprising to discover such a large patch of algal reefs that are relatively undisturbed by human activities," said Allen Chao-lun Chen, an associate researcher at Academia Sinica’s Research Center for Biodiversity Aug. 14.

According to Chen, algal reefs, formed by crystalline calcium carbonates left by dead calcareous algae, usually grow at the extremely slow rate of 0.1 centimeters to 0.2 centimeters in thickness per year. Coral communities can be found in waters 1 kilometer off the coastline at a depth of 8 meters to 10 meters.

In addition to the newly-discovered algal reef, Shanyuan Bay also boasts a dense and diverse cornularia coral community in which a wealth of fish, shrimp and shell species live–a phenomenon not seen in other areas in Taiwan, Chen noted.

The largest algal reef in Taiwan was located off Taoyuan County in northwestern Taiwan, which is 4 kilometers long and 500 meters wide. Most of Taiwan’s coral reefs are found off the island’s southern coastlines, as well as its outlying islands.

The discovery coincides with a U.N. global coral reefs survey and the International Year of the Reef. Chen’s decade-long study to conduct a survey of the marine ecology in Shanyuan Bay, Green Island, and the Penghu Islands was commissioned by the ROC government this year.

According to the researcher, the most encouraging part of his find was that a stem of Oulophyllia bennettae coral was seen in the bay. Chen explained this was the first time the coral strain, which is normally seen in the Indian Ocean, had been recorded in Taiwanese waters.

But Chen expressed concern that unchecked tourism development could harm coral reefs in the region. "Since some areas of the algae reefs have already been damaged, the government should take immediate steps to better manage and protect Shanyuan Bay."

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Drilling for Oil Way, Way Offshore

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Time Magazine, 18th August

Anyone who ever doubted the centrality of oil and natural gas to the global economy should have been convinced by the political events of the past few months. As petroleum prices have risen to record levels, the spiraling price of gasoline has become issue number one in the American Presidential election. That’s prompted Republican candidate John McCain to make expanded offshore oil drilling a focus of his campaign. For years, offshore drilling has been illegal outside parts of the Gulf of Mexico due to environmental concerns, with public support. But that has reversed in recent months, with even green Californians moving in favor of drilling. Barring a sudden national move to adopt alternative fuels, we can expect that reversal to continue — as oil prices rise, so will pressure to "drill here and drill now," as McCain has put it.

Whatever that means for offshore drilling in the U.S., the real victims of the global thirst for petroleum will be overseas — areas that, until the recent price rise, were too remote and forbidding to be worth drilling. Case in point: the vast, impenetrable western reaches of the Amazon. Touching parts of Bolivia, Peru, Ecuador, Columbia and Brazil, the western Amazon has remained relatively unscathed compared to the eastern stretches of the rainforest, which have been ravaged by logging. With few roads, the western Amazon has remained so undisturbed that there are still new indigenous tribes living somewhere inside the jungle who have never encountered the outside world.

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Blog wars – Marohasy and Rush Limbaugh to the rescue

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August 09, 2008

HAS global warming stopped? The question alone is enough to provoke scorn from the mainstream scientific community and from the Government, which says the earth has never been hotter. But tell that to a new army of sceptics who have mushroomed on internet blog sites and elsewhere in recent months to challenge some of the most basic assumptions and claims of climate change science.

Their claims are provocative and contentious but they are also attracting attention, so much sothat mainstream scientists are being forced to respond.

The bloggers and others make several key claims. They say the way of measuring the world’s temperature is frighteningly imprecise and open to manipulation. They argue that far from becoming hotter, the world’s temperatures have cooled in the past decade, contrary to the overwhelming impression conveyed by scientists and politicians.

As such, they say there should be far greater scepticism towards the apocalyptic predictions about climate change. Even widely accepted claims, such as that made by Climate Change Minister Penny Wong that “the 12 hottest years in history have all been in the last 13 years”, are being openly challenged.

“She is just plain wrong,” says Jennifer Marohasy, a biologist and senior fellow of the Institute of Public Affairs. “It’s not a question of debate. What about the medieval warming period? The historical record shows they were growing wine in England, for goodness sake; come on. It is not disputed by anyone that the Vikings arrived in Greenland in AD900 and it was warmer than Greenland is now. What Penny Wong is doing is being selective and saying that is a long time ago.”

But selective use of facts and data is fast becoming an art form on both sides of the climate change debate now that real money is at stake as the West ponders concrete schemes to reduce carbon emissions. So what is the validity of some of the key claims being made by these new blogger sceptics?

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