Category Archives: climate change

climate change, coral, coral disease

Annual Reviews.org: Climate change influences on marine infectious disease: implications for management and society by Burge, Eakin, Friedman, Froelich, Hershberger, Hoffman, Petes, Preager, Weil, Willis, Ford and Harvell.

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2014. *Annual Reviews in Marine Science*. 6: 249-277

Available online:
http://www.annualreviews.org/doi/abs/10.1146/annurev-marine-010213-135029

Climate Change Influences on Marine Infectious Diseases: Implications for Management and Society
Annual Review of Marine Science
Vol. 6: 249-277 (Volume publication date January 2014)
First published online as a Review in Advance on June 27, 2013
DOI: 10.1146/annurev-marine-010213-135029

Colleen A. Burge,1 C. Mark Eakin, Carolyn S. Friedman, Brett Froelich, Paul K. Hershberger, Eileen E. Hofmann, Laura E. Petes, Katherine C. Prager, Ernesto Weil, Bette L. Willis, Susan E. Ford, and C. Drew Harvell1
1Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853; email: cab433@cornell.edu, cdh5@cornell.edu*

ABSTRACT

Infectious diseases are common in marine environments, but the effects of a changing climate on marine pathogens are not well understood. Here we review current knowledge about how the climate drives host-pathogen interactions and infectious disease outbreaks. Climate-related impacts on marine diseases are being documented in corals, shellfish, finfish, and humans; these impacts are less clearly linked for other organisms. Oceans and people are inextricably linked, and marine diseases can both directly and indirectly affect human health, livelihoods, and well-being. We recommend an adaptive management approach to better increase the resilience of ocean systems vulnerable to marine diseases in a changing climate. Land-based management methods of quarantining, culling, and vaccinating are not successful in the ocean; therefore, forecasting conditions that lead to outbreaks and designing tools/approaches to influence these conditions may be the best way to manage marine disease.

Special thanks to Coral-list post by Colleen Burge

climate change

Common Dreams: Human Assault Pushes Ocean to Limit Unseen in 300 Million Years

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http://www.commondreams.org/headline/2013/10/03

Published on Thursday, October 3, 2013 by Common Dreams

‘We are entering an unknown territory of marine ecosystem change,’ warns report. ‘The next mass extinction may have already begun.’
– Jon Queally, staff writer

The news, the evidence that supports it, and the warning that accompanies it could hardly be more dire.

The latest audit by an international team of marine scientists at the International Programme on the State of the Ocean (IPSO) found that the world’s oceans and marine life are facing an unprecedented threat by combination of industrial pollution, human-driven global warming and climate change, and continued and rampant overfishing.

According to the report, The State of the Ocean 2013: Perils, Prognoses and Proposals, the degradation of the ocean ecosystem means that its role as Earth’s ‘buffer’ is being seriously compromised. As a result, the authors of the report call for “urgent remedies” because the “rate, speed, and impacts of change in the global ocean are greater, faster, and more imminent than previously thought.”

“[Last week’s] UN climate report confirmed that the ocean is bearing the brunt of human-induced changes to our planet. These findings give us more cause for alarm – but also a roadmap for action. We must use it.” -Prof. Dan Laffoley, IUCN

Driven by accumulations of carbon, the scientists found, the rate of acidification in the oceans is the highest its been in over 300 million years. Additionally, de-oxygenation–caused by both warming and industrial runoff–is stripping the ocean of its ability to support the plants and animals that live in it.

The combined stressors, according to the report, are “unprecedented in the Earth’s known history. We are entering an unknown territory of marine ecosystem change, and exposing organisms to intolerable evolutionary pressure. The next mass extinction may have already begun.”

Professor Alex Rogers of Somerville College, Oxford, and Scientific Director of IPSO said: “The health of the ocean is spiraling downwards far more rapidly than we had thought. We are seeing greater change, happening faster, and the effects are more imminent than previously anticipated. The situation should be of the gravest concern to everyone since everyone will be affected by changes in the ability of the ocean to support life on Earth.”

Among the report’s comprehensive findings, the panel identified the following areas as of greatest cause for concern:

• De-oxygenation: the evidence is accumulating that the oxygen inventory of the ocean is progressively declining. Predictions for ocean oxygen content suggest a decline of between 1% and 7% by 2100. This is occurring in two ways: the broad trend of decreasing oxygen levels in tropical oceans and areas of the North Pacific over the last 50 years; and the dramatic increase in coastal hypoxia (low oxygen) associated with eutrophication. The former is caused by global warming, the second by increased nutrient runoff from agriculture and sewage.

• Acidification: If current levels of CO2 release continue we can expect extremely serious consequences for ocean life, and in turn food and coastal protection; at CO2 concentrations of 450-500 ppm (projected in 2030-2050) erosion will exceed calcification in the coral reef building process, resulting in the extinction of some species and decline in biodiversity overall.

• Warming: As made clear by the IPCC, the ocean is taking the brunt of warming in the climate system, with direct and well-documented physical and biogeochemical consequences. The impacts which continued warming is projected to have in the decades to 2050 include: reduced seasonal ice zones, including the disappearance of Arctic summer sea ice by ca. 2037; increasing stratification of ocean layers, leading to oxygen depletion; increased venting of the GHG methane from the Arctic seabed (a factor not considered by the IPCC); and increased incidence of anoxic and hypoxic (low oxygen) events.

• The ‘deadly trio’ of the above three stressors – acidification, warming and deoxygenation – is seriously effecting how productive and efficient the ocean is, as temperatures, chemistry, surface stratification, nutrient and oxygen supply are all implicated, meaning that many organisms will find themselves in unsuitable environments. These impacts will have cascading consequences for marine biology, including altered food web dynamics and the expansion of pathogens.

• Continued overfishing is serving to further undermine the resilience of ocean systems, and contrary to some claims, despite some improvements largely in developed regions, fisheries management is still failing to halt the decline of key species and damage to the ecosystems on which marine life depends. In 2012 the UN FAO determined that 70% of world fish populations are unsustainably exploited, of which 30% have biomass collapsed to less than 10% of unfished levels. A recent global assessment of compliance with Article 7 (fishery management) of the 1995 FAO Code of Conduct for Responsible Fisheries, awarded 60% of countries a “fail” grade, and saw no country identified as being overall “good”.

Regarding the urgency of the crisis, the marine scientists issued a stark warning to world governments, called on leaders to take immediate action, and offered the following steps they said “must” be taken:

• Reduce global C02 emissions to limit temperature rise to less than 2oC, or below 450 CO2e. Current targets for carbon emission reductions are insufficient in terms of ensuring coral reef survival and other biological effects of acidification, especially as there is a time lag of several decades between atmospheric CO2 and CO2 dissolved in the ocean. Potential knock-on effects of climate change in the ocean, such as methane release from melting permafrost, and coral dieback, mean the consequences for human and ocean life could be even worse than presently calculated.

• Ensure effective implementation of community- and ecosystem-based management, favouring small-scale fisheries. Examples of broad-scale measures include introducing true co-management with resource adjacent communities, eliminating harmful subsidies that drive overcapacity, protection of vulnerable marine ecosystems, banning the most destructive fishing gear, and combating IUU fishing.

• Build a global infrastructure for high seas governance that is fit-for-purpose. Most importantly, secure a new implementing agreement for the conservation and sustainable use of biodiversity in areas beyond national jurisdiction under the auspices of UNCLOS.

In response to the IPSO study that arrived just one week after the IPCC report on climate change which also highlighted the threat of global warming to the oceans, Professor Dan Laffoley, of the International Union for Conservation of Nature, said: “What these latest reports make absolutely clear is that deferring action will increase costs in the future and lead to even greater, perhaps irreversible, losses. The UN climate report confirmed that the ocean is bearing the brunt of human-induced changes to our planet. These findings give us more cause for alarm – but also a roadmap for action. We must use it.”

climate change, coral reefs, reef health

Common Dreams: ‘Inhospitable Oceans’ Acidifying at Rate Unseen in 250 Million Years (or Ever)

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http://www.commondreams.org/headline/2013/08/26-0

Published on Monday, August 26, 2013
New study shows oceans in peril as acidification is happening at rate perhaps never seen in planet’s history
– Jon Queally, staff writer

ocean
(Photo: ‘Rough Ocean’/Flickr/Jacqueline Fasser)In both a new study published Monday and in a newspaper interview over the weekend, German marine biologist Hans Poertner warns the world that the crisis of ocean acidification—an intricately woven aspect of global warming and climate change—is now happening at a rate unparalleled in the life of the oceans for at least 250 million years and perhaps the fastest rate ever in the planet’s entire existence.

“The current rate of change is likely to be more than 10 times faster than it has been in any of the evolutionary crises in the earth’s history,” said Poertner in an interview with environmental journalist Fiona Harvey.

Ocean acidification—often called climate change’s “evil twin” by scientists and experts—happens as the pH level of seawater dwindles as it absorbs increasing amount of carbon dioxide (CO2) and though such fluctuations are a normally occurring phenomenon, when the balance tips too far, the acidification can imperil numerous types of marine life and is especially threatening to coral, shell fish, and other essential members of the ocean’s ecosystems.

Poertner—whose study, Inhospitable Oceans, was published Monday in the journal Nature Climate Change—says that if humanity’s industrial carbon emissions continue with a “business as usual” attitude, the problem of the oceans will be catastrophic.

To make comparisons, the study looked back at the ancient fossil record of the ocean to learn about what we can expect if the process continues unchecked. “The [effects observed] among invertebrates resembles those seen during the Permian Triassic extinctions 250m years ago, when carbon dioxide was also involved,” Poertner said. “The carbon dioxide range at which we see this sensitivity [to acidification] kicking in are the ones expected for the later part of this century and beyond.”

As Harvey explains:

Oceans are one of the biggest areas of focus for current climate change research. The gradual warming of the deep oceans, as warmer water from the surface circulates gradually to lower depths, is thought to be a significant factor in the earth’s climate. New science suggests that the absorption of heat by the oceans is probably one of the reasons that the observed warming in the last 15 years has been at a slightly slower pace than previously, and this is likely to form an important part of next month’s Intergovernmental Panel on Climate Change (IPCC) report.

The IPCC report, the first since 2007, will provide a comprehensive picture of our knowledge of climate change. It is expected to show that scientists are at least 95% certain that global warming is happening and caused by human activity, but that some uncertainties remain over the exact degree of the planet’s sensitivity to greenhouse gas increases.

And as Time points out in its review of the study:

Corals are likely to have the toughest time. The invertebrate species secretes calcium carbonate to make the rocky coastal reefs that form the basis of the most productive—and beautiful—ecosystems in the oceans. More acidic oceans will interfere with the ability of corals to form those reefs. Some coral have already shown the ability to adapt to lower pH levels, but combined with direct ocean warming—which can lead to coral bleaching, killing off whole reefs—many scientists believe that corals could become virtually extinct by the end of the century if we don’t reduce carbon emissions.

The Nature Climate Change study found that mollusks like oysters and squids will also struggle to adapt to acidification, though crustaceans like lobsters and crabs—which build lighter exoskeletons—seem likely to fare better. With fish it’s harder to know, though those species that live among coral reefs could be in trouble should the coral disappear. But ultimately, as the authors point out, “all considered groups are impacted negatively, albeit differently, even by moderate ocean acidification.” No one gets out untouched.

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