News Article | February 19, 2017
The embattled Great Barrier Reef could face yet more severe coral bleaching in the coming month, with areas badly hit by last year’s event at risk of death. Images taken by local divers last week and shared exclusively with the Guardian by the Australian Marine Conservation Society show newly bleached corals discovered near Palm Island. Most of the Great Barrier Reef has been placed on red alert for coral bleaching for the coming month by the US National Oceanic and Atmospheric Administration (NOAA). Its satellite thermal maps have projected unusually warm waters off eastern Australia after an extreme heatwave just over a week ago saw land temperatures reach above 47C in parts of the country. According to the Great Barrier Reef Marine Park Authority, sea surface temperatures from Cape Tribulation to Townsville have been up to 2C higher than normal for the time of year for more than a month. The NOAA Coral Reef Watch’s forecast for the next four weeks has placed an even higher level alert on parts of the far northern, northern and central reef, indicating mortality is likely. Corals south of Cairns, in the Whitsundays and parts of the far northern reef that were badly hit by last year’s mass bleaching event are at fatal risk. Imogen Zethoven, the Great Barrier Reef’s campaign director for the AMCS, said the projections for the next four weeks, plus evidence of new coral bleaching, were “extremely concerning”. The bleaching that occurred over eight to nine months of last year was the worst-ever on record for the Great Barrier Reef, with as much as 85% of coral between Cape York and Lizard Island dying. Twenty-two per cent of corals over the entire reef are dead. Zethoven pointed to projections by NOAA that severe bleaching of the Great Barrier Reef would occur annually by 2043 if nothing was done to reduce emissions. “The reef will be gone before annual severe bleaching,” she said. “It won’t survive even biennial bleaching.” The $1bn reef fund announced by the prime minister, Malcolm Turnbull, in June last year was a “cynical rebadging exercise” undercut by its support for fossil fuel initiatives such as Adani’s Carmicheal coalmine “that will spell catastrophe for the reef”, Zethoven said. “There’s no doubt about that anymore,” she said. “They know what they are doing and they should come clean with the Australian public that they have no interest in the long-term survival of the Great Barrier Reef. “To the average person on the street, that’s what it looks like. And if the government thinks that’s not the case, they’re out of touch.” In December last year the government’s Northern Australia Infrastructure Fund granted Adani “conditional approval” to $1bn loan for its Carmicheal coalmine and rail project in central Queensland, which could produce 60m tons of coal annually for 60 years. Warmer ocean temperatures brought about by climate change is a key factor in coral bleaching. Polling suggests that more than two-thirds of Australians believe the reef’s condition should be declared a national emergency. Zethoven said the government had made “a very deliberate decision to go down the coal road”, despite it jeopardising the reef’s future prospects as well as the 70,000 jobs in regional Queensland that depend on it. John Rumney, a diving operator based in Port Douglas, said the “commercial advantage” to saving the reef went beyond jobs. Much of coastal Queensland was “majorly invested” in reef tourism, he said. The federal government’s measures to save the reef were hypocrisy and lip service, he said, when it was simultaneously “actively supporting the cause of the cancer – the worst cause”. “It’s immoral that those of us who are making our living from a healthy environment are paying taxes to subsidise infrastructure that’s going to cause climate change in a major way for the next 50 years,” he said. “If this all goes ahead, we’re basically dooming our tourism industry.” Rumney said he had seen new and extensive bleaching of corals from Cairns to Townsville. “There are definite large areas of mortality. It’s just the next depressing moment. Before, the reef has bleached and recovered but now we’re talking about how often is it bleaching and what percentage is left.” Areas that suffered in last year’s event were now less resilient and there seemed to be less coral strong enough to spawn. Climate change-induced mass bleaching increasingly resembled a catastrophe the reef would be unable to recover from, he said. “It’s weaker, just like humans,” Rumney said. “If you’re already down and out with a cold or cancer, you’re less resilient – the next thing that comes along is going to knock you back more. “It’s the continual onslaught that will eventually kill the reef.”
News Article | April 4, 2016
An aerial view of a section of the Great Barrier Reef, with bleached corals visible in the water. More The northern part of the world's largest coral reef ecosystem is experiencing "the worst mass bleaching event in its history," according to a statement released Tuesday (March 29) by the Australian Research Council. Documented by the National Coral Bleaching Taskforce (NCBT) in aerial surveys, observations of more than 500 coral reefs spanning 2,485 miles (4,000 kilometers) showed that the majority of reefs were undergoing extensive and severe bleaching. "Almost without exception, every reef we flew across showed consistently high levels of bleaching, from the reef slope right up onto the top of the reef," said Terry Hughes of the NCBT, calling the surveys "the saddest research trip of my life." [Worst Coral Reef Bleaching on Record for the Great Barrier Reef | Aerial Video] Bleaching happens when corals are exposed to stresses such as warmer-than-average waters for prolonged periods of time. The corals respond to the stress by expelling the algae that provide them with their color, which makes the corals look like they've been bleached white. Bleaching can be fatal for corals if the stress is too intense, or if it continues for too long and the algae are unable to recolonize them. Australia's Great Barrier Reef (GBR) covers 134,364 square miles (348,000 square kilometers), making it larger than the U.K., Switzerland and the Netherlands combined, according to the Great Barrier Reef Marine Park Authority. Recognized as a World Heritage Area in 1981, the reef contains 400 types of coral and hosts 1,500 types of fish and 4,000 mollusk species, as well as other marine life such as large green turtles and dugongs ("sea cows"). The GBR experienced bleaching events in 1998 and in 2002, but the current mass bleaching is much more severe, experts are saying. Rebecca Albright, a marine biologist with the Carnegie Institution for Science in Washington, D.C., has studied the GBR since 2011. Albright told Live Science that 95 percent of the GBR's northern reefs are currently showing signs of extreme bleaching, compared with 18 percent that experienced bleaching in 2002. Even the more robust corals are affected, Albright said, another sign that this event is particularly serious. She cautioned that it's still too early to assess the long-term impacts of bleaching on the corals, though estimates of coral mortality anticipate losses of about 50 percent. Two factors are responsible for stressing the corals, Albright said: climate change, which is driving ocean temperatures upward, and a strong El Niño — a cyclical climate event associated with warmer-than-average sea surface temperatures in the tropical Pacific. And with El Niño conditions expected to extend through 2016, that doesn't bode well for the corals' recovery. "Corals are sensitive to not only the anomaly in temperature — how high it goes — but also the duration of that exposure," Albright told Live Science. "This kind of perfect storm of all these factors coming together makes this a catastrophic scenario right now." [Images: Colorful Corals of the Deep Barrier Reef] But what's happening to the GBR is only part of the picture. A global bleaching event prolonged by El Niño is currently underway — "the longest coral die-off on record," according to a statement released by the National Oceanic and Atmospheric Administration (NOAA) on Feb. 23. Mark Eakin, coordinator of the NOAA Coral Reef Watch program, told Live Science that the event, which began in 2014 in the Pacific, could linger through 2017. "We consider it a global bleaching event if it's widespread in all three of the major ocean basins — Indian, Atlantic and Pacific," he said. Eakin described current reports of bleaching that extend over half of the Southern Hemisphere, with severe bleaching in New Caledonia, Fiji and southern Indonesia, as well as in the GBR. Even fast-growing corals take decades to develop, so damaged reefs will need time before they're restored to their former level of health, Eakin said. And recovery time may be in short supply. Global bleaching events have been expanding their reach and increasing in severity since the first event was documented in 1998, Eakin told Live Science.
Maynard J.A.,University of Melbourne |
Anthony K.R.N.,James Cook University |
Anthony K.R.N.,University of Queensland |
Harvell C.D.,Cornell University |
And 7 more authors.
Coral Reefs | Year: 2011
Links between anomalously high sea temperatures and outbreaks of coral diseases known as White Syndromes (WS) represent a threat to Indo-Pacific reefs that is expected to escalate in a changing climate. Further advances in understanding disease aetiologies, determining the relative importance of potential risk factors for outbreaks and in trialing management actions are hampered by not knowing where or when outbreaks will occur. Here, we develop a tool to target research and monitoring of WS outbreaks in the Great Barrier Reef (GBR). The tool is based on an empirical regression model and takes the form of user-friendly interactive ~1. 5-km resolution maps. The maps denote locations where long-term monitoring suggests that coral cover exceeds 26% and summer temperature stress (measured by a temperature metric termed the mean positive summer anomaly) is equal to or exceeds that experienced at sites in 2002 where the only severe WS outbreaks documented on the GBR to date were observed. No WS outbreaks were subsequently documented at 45 routinely surveyed sites from 2003 to 2008, and model hindcasts for this period indicate that outbreak likelihood was never high. In 2009, the model indicated that outbreak likelihood was high at north-central GBR sites. The results of the regression model and targeted surveys in 2009 revealed that the threshold host density for an outbreak decreases as thermal stress increases, suggesting that bleaching could be a more important precursor to WS outbreaks than previously anticipated, given that bleaching was severe at outbreak sites in 2002 but not at any of the surveyed sites in 2009. The iterative approach used here has led to an improved understanding of disease causation, will facilitate management responses and can be applied to other coral diseases and/or other regions. © 2010 Springer-Verlag.
Bauman A.G.,James Cook University |
Feary D.A.,University of Technology, Sydney |
Heron S.F.,NOAA Coral Reef Watch |
Heron S.F.,James Cook University |
And 2 more authors.
Marine Pollution Bulletin | Year: 2013
Multivariate analysis revealed distinct sub-regional coral communities among the southern Persian Gulf, Strait of Hormuz, and Gulf of Oman. Differences in community structure among locations were associated with considerable spatial heterogeneity in oceanic conditions, and strong directional environmental gradients. Despite clear community differences, considerable changes to coral community structure have occurred throughout the northeastern Arabian Peninsula as compared with previous studies. The most dramatic of these are the apparent changes from Acropora dominated to poritid and faviid dominated communities, particularly in the southern Persian Gulf and Strait of Hormuz. Although temperature and salinity have previously been cited as the major environmental factors structuring coral communities around the region, additional environmental parameters, including chlorophyll- a, surface currents and winds are shown to be important in structuring reef communities throughout the northeastern Arabian Peninsula. © 2012 Elsevier Ltd.
Welch H.,James Cook University |
Pressey R.L.,James Cook University |
Heron S.F.,NOAA Coral Reef Watch |
Heron S.F.,James Cook University |
And 2 more authors.
Ecography | Year: 2016
Spatial management of the highly dynamic pelagic realm, and the highly mobile species it supports, requires dynamic processes to be incorporated into reserve design. To achieve this, planners need information on how these processes vary across space and time, and how this variation relates to species of conservation interest. This study presents a new method of quantifying variability that captures both between- and within-year changes in variables of interest. We applied this method to remotely-sensed chlorophyll-a in the Coral Sea to find five distinct regimes of variation that serve as surrogates for assemblages of species of conservation interest. We performed a gap analysis to determine protection of the regimes both internationally and nationally within Australia's network of marine reserves in the Coral Sea. We also identified key areas for protection within each regime, in terms of chlorophyll-a variability and species associations, and examined their protection status. Depending on conservation objectives, reserve systems that span multiple national jurisdictions and a rezoning of Australian national waters might be necessary to meet protection requirements for the regimes and for key areas within them. The current suspension and review of the Coral Sea Commonwealth Marine Reserve management plans and the recent proclamation of New Caledonia's as yet unzoned Coral Sea Nature Park offer planners an opportunity to incorporate dynamic processes into conservation planning for the Coral Sea. The method we present can be applied at other locations for time-series of any variable/s of interest, aiding the spatial management of dynamic features in both marine and terrestrial contexts. Ecography © 2016 Nordic Society Oikos
Pollock F.J.,James Cook University |
Pollock F.J.,Australian Institute of Marine Science |
Lamb J.B.,James Cook University |
Lamb J.B.,Australian Institute of Marine Science |
And 9 more authors.
PLoS ONE | Year: 2014
In recent decades, coral reef ecosystems have declined to the extent that reefs are now threatened globally. While many water quality parameters have been proposed to contribute to reef declines, little evidence exists conclusively linking specific water quality parameters with increased disease prevalence in situ. Here we report evidence from in situ coral health surveys confirming that chronic exposure to dredging-associated sediment plumes significantly increase the prevalence of white syndromes, a devastating group of globally important coral diseases. Coral health surveys were conducted along a dredging-associated sediment plume gradient to assess the relationship between sedimentation, turbidity and coral health. Reefs exposed to the highest number of days under the sediment plume (296 to 347 days) had two-fold higher levels of disease, largely driven by a 2.5-fold increase in white syndromes, and a six-fold increase in other signs of compromised coral health relative to reefs with little or no plume exposure (0 to 9 days). Multivariate modeling and ordination incorporating sediment exposure level, coral community composition and cover, predation and multiple thermal stress indices provided further confirmation that sediment plume exposure level was the main driver of elevated disease and other compromised coral health indicators. This study provides the first evidence linking dredging-associated sedimentation and turbidity with elevated coral disease prevalence in situ. Our results may help to explain observed increases in global coral disease prevalence in recent decades and suggest that minimizing sedimentation and turbidity associated with coastal development will provide an important management tool for controlling coral disease epizootics.
Beeden R.,Climate Change Group |
Beeden R.,James Cook University |
Maynard J.A.,CNRS Insular Research Center and Environment Observatory |
Marshall P.A.,Climate Change Group |
And 3 more authors.
Environmental Management | Year: 2012
Predicted increases in coral disease outbreaks associated with climate change have implications for coral reef ecosystems and the people and industries that depend on them. It is critical that coral reef managers understand these implications and have the ability to assess and reduce risk, detect and contain outbreaks, and monitor and minimise impacts. Here, we present a coral disease response framework that has four core components: (1) an early warning system, (2) a tiered impact assessment program, (3) scaled management actions and (4) a communication plan. The early warning system combines predictive tools that monitor the risk of outbreaks of temperature-dependent coral diseases with in situ observations provided by a network of observers who regularly report on coral health and reef state. Verified reports of an increase in disease prevalence trigger a tiered response of more detailed impact assessment, targeted research and/or management actions. The response is scaled to the risk posed by the outbreak, which is a function of the severity and spatial extent of the impacts. We review potential management actions to mitigate coral disease impacts and facilitate recovery, considering emerging strategies unique to coral disease and more established strategies to support reef resilience. We also describe approaches to communicating about coral disease outbreaks that will address common misperceptions and raise awareness of the coral disease threat. By adopting this framework, managers and researchers can establish a community of practice and can develop response plans for the management of coral disease outbreaks based on local needs. The collaborations between managers and researchers we suggest will enable adaptive management of disease impacts following evaluating the cost-effectiveness of emerging response actions and incrementally improving our understanding of outbreak causation. © 2011 Her Majesty the Queen in Rights of Australia.
Anderson K.D.,James Cook University |
Heron S.F.,NOAA Coral Reef Watch |
Heron S.F.,James Cook University |
Pratchett M.S.,James Cook University
Coral Reefs | Year: 2015
Reef-building corals are extremely sensitive to changing temperature regimes, such that sustained increases in ocean temperatures are generally expected to have negative effects on coral growth and survivorship. At high-latitude reefs, however, projected increases in ocean temperature may actually increase coral growth (relaxing constraints imposed by cool winter temperatures), though this will depend upon on the rate and extent of declines in aragonite saturation, which is already much lower at high latitudes. This study quantified linear extension rates of six scleractinian corals, Acropora yongei, Isopora cuneata, Pocillopora damicornis, Porites heronensis, Seriatoporahystrix, and Stylophora pistillata, at Lord Howe Island in 2010/11. Contemporary growth rates were compared to equivalent data collected in 1994/95. There was marked interspecific variation in growth rates, with A. yongei growing almost twice the rate of all other species. Temporal changes in annual growth also varied among species. Growth rates of both A. yongei and Pocillopora damicornis were 30 % of that recorded in 1994/95. However, growth rates of Porites heronensis had not changed. Declines in the growth rates of these branching species may be attributable to declines in aragonite saturation or increases in summertime temperatures above limits for optimal growth, but either way it appears that climate change is having negative effects on corals, even at subtropical locations. © 2014, Springer-Verlag Berlin Heidelberg.
Chollett I.,University of Exeter |
Chollett I.,University of Queensland |
Muller-Karger F.E.,University of South Florida |
Heron S.F.,NOAA Coral Reef Watch |
And 4 more authors.
Marine Pollution Bulletin | Year: 2012
Recent changes in ocean temperature have impacted marine ecosystem function globally. Nevertheless, the responses have depended upon the rate of change of temperature and the season when the changes occur, which are spatially variable. A rigorous statistical analysis of sea surface temperature observations over 25. years was used to examine spatial variability in overall and seasonal temperature trends within the wider Caribbean. The basin has experienced high spatial variability in rates of change of temperature. Most of the warming has been due to increases in summer rather than winter temperatures. However, warming was faster in winter in the Loop Current area and the south-eastern Caribbean, where the annual temperature ranges have contracted. Waters off Florida, Cuba and the Bahamas had a tendency towards cooling in winter, increasing the amplitude of annual temperature ranges. These detailed patterns can be used to elucidate ecological responses to climatic change in the region. © 2012 Elsevier Ltd.
News Article | July 7, 2015
Warming temperatures are threatening coral reefs in the northern hemisphere, including many in U.S. waters, scientists are warning. Unusually warm ocean temperatures are putting coral at risk across the equatorial and north Pacific and western Atlantic oceans, the National Oceanic and Atmospheric Administration says. The rise in temperatures can lead to coral bleaching, a phenomenon that sees coral release the symbiotic algae that lives within it, turning the coral pale or white. That eliminates a major source of food and leaves the coral more vulnerable to disease, NOAA scientists say, and in extreme cases can cause entire sections of reefs to die, destroying a habitat important to fish and shellfish. "The bleaching that started in June 2014 has been really bad for corals in the western Pacific," says Mark Eakin, coordinator of the NOAA Coral Reef Watch. "We are worried that bleaching will spread to the western Atlantic and again into Hawaii." If bleaching occurs again this year, it would mark the first time it has occurred in consecutive years in the Hawaiian archipelago. Reef loss from coral bleaching has a long-term affect, as reefs normally take decades to recover, scientists point out. Dead reefs degrade as erosion destroys the structures the corals have painstakingly built up. The result is less protection for shorelines and fewer habitats for marine life, they say. In addition to Hawaii, Florida also experienced warmer temperatures, which hit coral nurseries in the Florida Keys in which researchers have attempted to grow threatened species of coral for harvesting and transplanting onto local reef systems. More bleaching this year could be disastrous for corals still attempting to recover from last year's warming stress, Eakin says. "Many healthy, resilient coral reefs can withstand bleaching as long as they have time to recover," Eakin says. "However, when you have repeated bleaching on a reef within a short period of time, it's very hard for the corals to recover and survive." The problem is compounded by other stresses, including overfishing and pollution, he adds. The warmer oceans in the Northern Hemisphere are being caused by both El Niño weather patterns and ongoing climate change, Eakin says. Although bleaching can be the result of light and nutrient levels as well as ocean temperatures, only very warm temperatures can cause the widespread bleaching scientists have detected beginning in 2014. Coral reefs play a critical role in marine ecosystems; although they are found on just 10 percent of the world's ocean floor, they provide homes and habitats for 25 percent of the globe's known marine species.