March 03, 2010
Climate change threatens coral reefs and precipitation along coasts.
"Coral reefs produce a volatile substance called dimethylsulphide or DMS which oxidizes in the atmosphere to produce cloud condensation nuclei (CCN). These are tiny sulphur aerosol particles around which water vapor condenses to form clouds," Jones explained to mongabay.com, adding that, "water vapor cannot form clouds without these tiny aerosol particles being present."
The DMS is produced by the algae living in coral tissues, causing the corals to produce the cloud-seeding substance, DMS, on a daily basis. However, Jones has also tracked important seasonal patterns. In Australia "we have found more cloud seeding substances are produced by coral reefs in the hot summer monsoonal season from November to February," he says.
"When we put small pieces of staghorn coral (Acropora the branching coral which is the dominant coral in the Indo-Pacific region) in chambers containing seawater at Heron Island coral cay the production of atmospheric DMS shuts down when we increase seawater temperatures by only 2 degrees Celsius above the yearly mean," says Jones who has published results showing that this occurs in the field as well as the laboratory. "What this suggests is that fewer CCN (cloud condensation nuclei) are produced over coral reefs during high sea surface temperatures and so cloud cover could be expected to be lower or non-existent during high seas surface temperatures."
This pattern of less cloud cover due to warmer temperatures can already be seen during El Nino years.
"What we think happens then is that during an El Nino which can produce doldrum conditions in the Great Barrier Reef, sometimes for a couple of weeks at a time, this process shuts down," says Jones, explaining a feedback system where the warmer temperatures decrease cloud cover through shutting down the coral's production of DMS, which in turn further warms the ocean since more sunlight reaches the sea surface. Once the sea surface temperatures exceed the coral's tolerance level, the corals suffer bleaching, which leads to wide-spread coral stress and even mortality.
"Consequently," Jones says, "no clouds, no rain in the regional areas where reefs occur."
The consequences of disrupting this natural process can be huge. For one thing Jones asserts that some rainforests are fed precipitation during certain seasons by the coral reef's ability to produce clouds
Jones says that the Australian government has a number of policies in place to protect coral reefs, but "what we don't have is funding of basic reef processes such as this one, which significantly can affect regional climate in the Great Barrier Reef."
Research into how ecosystems, such as coral reefs and forests, may be involved in regional climate patterns has been gaining steam over the years. Two Russian scientists have published a number of studies on a controversial theory that forests actually 'pump' rain from the coast to continent's interiors.
If such theories withstand the test of time, and science, they could have widespread implications for the conservation of both forests and coral reefs, adding a new and vital ecosystem-service provided by these two threatened environments: the 'makers' and 'movers' of precipitation.
Jones writes: "The attached picture shows Rangiroa coral atoll in French Polynesia producing these nascent clouds on the windward side of the atoll where the wind is affecting that part of the island and turbulence is occurring over the barrier reef which circles the atoll. They are quite low lying clouds and as they travel over the ocean the hygroscopic (water loving) aerosol particles pick up moisture. If conditions are suitable rain will occur when the CCN grow to produce cloud droplets with enough mass to fall as rain." Photo by: Pacific Promotion Tahit).
Revolutionary new theory overturns modern meteorology with claim that forests move rain
(04/01/2009) Two Russian scientists, Victor Gorshkov and Anastassia Makarieva of the St. Petersburg Nuclear Physics, have published a revolutionary theory that turns modern meteorology on its head, positing that forests—and their capacity for condensation—are actually the main driver of winds rather than temperature. While this model has widespread implications for numerous sciences, none of them are larger than the importance of conserving forests, which are shown to be crucial to 'pumping' precipitation from one place to another. The theory explains, among other mysteries, why deforestation around coastal regions tends to lead to drying in the interior.
If protected coral reefs can recover from global warming damage
(01/10/2010) A study in the Caribbean has found that coral reefs can recover from global warming impacts, such as coral bleaching, if protected from fishing. Marine biologists have long been worried that coral reefs affected by climate change may be beyond recovery, however the new study published in PLoS ONE shows that alleviating another threat, overfishing, may allow coral reefs to cope with climate change.
Climate change causing irreversible acidification in world's oceans
(12/15/2009) A new study from the Secretariat of the Convention on Biological Diversity has synthesized over 300 reports on ocean acidification caused by climate change. The report finds that increasing ocean acidification in the oceans will lead to irreversible damage in the world's oceans, creating a less biodiverse marine environment. Released today the report determines that the threat to marine life by ocean acidification must be considered by policymakers at the UN Climate Change Conference in Copenhagen.
Coral reef troubles indicate broader ecological problems
(11/10/2009) Today, many of our planet's natural areas are seriously threatened by human incursion, overexploitation and global warming: Less than a fifth of the world's original forest cover remains in unfragmented tracts, while just one-third of coastal mangroves survive to protect coastlines from storms and erosion. But none of these are declining as rapidly as coral reefs. By revealing what could be in store for other natural systems, reefs resemble the proverbial canary in a coal mine.
Loss of Great Barrier Reef due to global warming would cost Australia $37.7 billion
(08/12/2009) A recent study reports that the loss of Australia’s Great Barrier Reef due to climate change poses a catastrophe not just for marine life, but would cost $37.7 billion during the next century.
Tropical storms may create seeds for reef restoration
(05/16/2009) Tropical reefs are easy to destroy and difficult to fix. It is estimated that global warming, unsustainable fishing, and pollution have already destroyed 20% of the world’s coral reefs. Recently, Virginia Garrison and Greg Ward of the United States Geological Survey (USGS) demonstrated how coral fragments that have broken loose during storms can be used to rebuild reefs. They reported their results in the October issue of Biological Conservation.
Coral reef loss in Caribbean leads to ongoing fish declines
(04/30/2009) Analyzing 48 surveys of Caribbean fish populations over fifty years, from 1955-2007, a new meta-study has found that fish populations in the famously clear waters began to drop in the mid-90s, leading to a consistent decline that hasn’t stopped. The study published in Current Biology discovered a region-wide decline of about 3-6 percent per year in three out of six trophic groups of fish, i.e. groupings of species categorized by their place on the food chain. The declines didn’t show major differences between species targeted by fishermen and those that are not, implying that overfishing isn’t the only cause of the decline in the Caribbean.
New protections for coral reefs and dwindling fish species in Belize
(04/27/2009) Coral reefs in Belize, considered to be some of the most pristine in the west, have secured additional protections. Rene Montero, the Minister of Agriculture and Fisheries, signed a set of new laws this month to protect Belize’s coral reefs and the fish that inhabit them. The additional laws protect increasingly overfished species, ban spearfishing in marine reserves, and create no-take zones, according to a press release from the Wildlife Conservation Society (WCS).
Ocean acidification is killing the Great Barrier Reef
(01/01/2009) Since 1990 the growth of coral in Australia's Great Barrier Reef has slowed its lowest rate in at least 400 years as a result of warming waters and ocean acidification, report researchers writing in Science. The finding portends a bleak near-term future for the giant reef ecosystem as well as calcifying marine organisms around the world.
Tropical ocean dead zones could increase 50 percent by 2050
(11/18/2008) If carbon dioxide levels continue to rise as expected, marine dead zones in the tropics are expected to increase by 50 percent in just over four decades, according to a new study from the Leibniz Institute of Marine Sciences in Germany. The expansion of marine dead zones in tropical seas could have devastating impacts on ocean ecosystems and fisheries.
Stopping ocean acidification would save billions of dollars in revenue
(11/12/2008) A new report from Oceana shows that action taken now to curb ocean acidification would not only preserve the world's coral reefs, but also save billions in lost revenue in the fishing and tourism industries.
'Safe' CO2 level may destroy the fishing industry, wreck reefs
(09/23/2008) An atmospheric carbon dioxide concentration of 450 parts-per-million (ppm) — a target level deemed safe by the United Nations Framework Convention on Climate Change (UNFCCC) — would be devastating to marine ecosystems warn scientists writing in the journal Geophysical Research Letters.
Saving oceans from acidification requires addressing climate policy
(08/27/2008) Ocean acidification driven by rising carbon dioxide emissions is a great threat to marine ecosystems and needs be addressed through climate policy and conservation measures, said top marine scientists meeting in Hawaii.
The long-ignored ocean emergency and what can be done to address it
(08/18/2008) This year has been full of bad news regarding marine ecosystems: one-third of coral species threatened with extinction, dead-zones spread to 415 sites, half of U.S. reefs in fair or bad condition, increase in ocean acidification, tuna and shark populations collapsing, and only four percent of ocean considered pristine. Jeremy Jackson, director of the Scripps Center for Marine Biodiversity and Conservation at the University of California, San Diego, synthesizes such reports and others into a new paper, published in the journal Proceedings of the Naional Academy of Sciences, that boldly lays out the scope of the oceanic emergency and what urgently needs to be done.
weather temperatures Coral Reefs climate change climate science precipitation Australia Coral Reefs and climate change coral bleaching coral corals jeremy hance green environment bold and dangerous ideas that may save the world conservation ecology ecological services ecosystem services environmental services forests marine conservation oceans protected areas rainforest rainforests saving rainforests strange storms threats to rainforests threats to the rainforest tropical forests
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