Wednesday, September 10, 2008
~ Wednesday, September 10, 2008 ~
R-reefs
E-Extinctions
E-Equals
F-Fatality
The reefs in the world NEED OUR help!!
Sunday, September 7, 2008
~ Sunday, September 07, 2008 ~
Coral reefs throughout the world face an array of threats: nutrient pollution, starfish predation and deadly bleaching that follows warmer sea temperatures. Yet they provide between $10,000 and $100,000 in economic benefits to nearby communities, according to one estimate, including everything from coastal protection from storm surges to better fishing. More than 75 percent of the world's reefs lie in the Pacific Ocean, where a new analysis reveals that an average of roughly 600 square miles of the marine outcroppings disappeared annually between 1968 and 2004—since 1995 the rate of their destruction has doubled.
"Global coral loss began earlier and is far more rapid and geographically extensive than we anticipated," says marine biologist John Bruno of the University of North Carolina at Chapel Hill. Twenty years ago, many reefs boasted living coral on more than 60 percent of their surfaces, he adds, but "today very few reefs in the Indo-Pacific, only about 1 or 2 percent, have coral cover close to the historical baseline."
Bruno and U.N.C. conservation biologist Elizabeth Selig sifted through more than 6,000 surveys, ranging from detailed studies of Australia's Great Barrier Reef to simple photos of reefs taken by sport diving organizations like Reef Check, to assess the state of coral cover. "Living coral cover is a metric of reef habitat quality and quantity analogous to coverage of trees as a measure of tropical forest loss," Bruno says. "The ability to include data from other sources really helped us expand the scope of our study."
By 2003 coral cover had slid from 42 percent in the 1980s to an average of just 22 percent of each reef's surface area, the researchers report in PLoS One. The decline accelerated after 1995, with an average loss of more than 1,200 square miles, or 2 percent of the total of living reef per year—more than double the rate of rainforest loss in the 1990s. "Corals are dying worldwide for a number of reasons, particularly because of pest outbreaks (diseases and predators) but also due to climate change, nutrient pollution, destructive fishing practices and coastal development that can smother corals with sediment," Bruno says.
Reefs in other parts of the world face similar hurdles, but recent research has shown that even severely degraded corals can recover, given the opportunity. "Even on Caribbean reefs in Jamaica, which are highly degraded, we have seen reefs bounce back surprisingly quickly," Bruno notes.
But Bruno says that can only be achieved if greenhouse emissions are reduced, dynamite and arsenic fishing is eliminated and other steps are taken to halt reef killers. Given the economic—and ecological—benefits such reefs provide, that may be a small sacrifice to make.
http://www.sciam.com/article.cfm?id=coral-reefs-losing-ground-in-pacific
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Reef Restoration Technology
Low voltage electrical currents applied through seawater crystallizes dissolved minerals onto steel structures. The resultant white carbonate (aragonite) is the same mineral that makes up natural coral reefs. Corals rapidly colonize and grow at faster than normal rates onto these coated structures. The change in the environment produced by electrical currents also accelerates formation and growth of both chemical limestone rock and the skeletons of corals and other shell-bearing organisms. Within the vicinity of the anode and cathode is a high pH environment which inhibits the growth of filamentous and fleshy algae, which compete with coral for space. This, and the increased growth rates cease when the mineral accretion process stops.[39]
The effects of mineral accretion is, however, only temporary. During the process the settled corals have an increased growth rate, and size, and density, but after the process is complete the corallites are comparable to naturally growing corallites in growth rate and density, and are about the same size or slightly smaller.[40]
Source for the few previous post and this : http://en.wikipedia.org/wiki/Coral_reef
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Marine Protected Areas
One method of coastal reef management that has become increasingly prominent is the implementation of Marine Protected Areas (MPAs). MPAs have been introduced in Southeast Asia and elsewhere around the world to attempt to promote responsible fishery management and habitat protection. Much like the designation of national parks and wild life refuges, potentially damaging extraction activities are prohibited. The objectives of MPAs are both social and biological, including restoration of coral reefs, aesthetic maintenance, increased and protected biodiversity, and economic benefits. Conflicts surrounding MPAs involve lack of participation, clashing views and perceptions of effectiveness, and funding.
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Protection and restoration
Aerial photo of Ahus Island, Papua New Guinea
Aerial photo of Ahus Island, Papua New Guinea
Inhabitants of Ahus Island, Manus Province, Papua New Guinea, have followed a generations-old practice of restricting fishing in six areas of their reef lagoon. While line fishing is permitted, net and spear fishing are restricted based on cultural traditions. The result is that both the biomass and individual fish sizes are significantly larger in these areas than in places where fishing is completely unrestricted.[35][36]
It is estimated that about 60% of the world's reefs are at risk due to destructive, human-related activities. The threat to the health of reefs is particularly strong in Southeast Asia, where an enormous 80% of reefs are considered endangered.
Organisations as Coral Cay, Counterpart [37] and the Foundation of the peoples of the South Pacific are currently undertaking coral reef/atoll restoration projects. They are doing so using simple methods of plant propagation. Other organisations as Practical Action have released informational documents on how to set-up coral reef restoration to the public.[38]
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Destruction worldwide
Coral reefs and fishes in Papua New Guinea
Coral reefs and fishes in Papua New Guinea
Southeast Asian coral reefs are at risk from damaging fishing practices (such as cyanide and blast fishing), overfishing, sedimentation, pollution and bleaching. A variety of activities, including education, regulation, and the establishment of marine protected areas are under way to protect these reefs. Indonesia, for example has nearly 33,000 square miles (85,000 km2) of coral reefs. Its waters are home to a third of the world's total corals and a quarter of its fish species. Indonesia's coral reefs are located in the heart of the Coral Triangle and have been victim to destructive fishing, unregulated tourism, and bleaching due to climatic changes. Data from 414 reef monitoring stations throughout Indonesia in 2000 found that only 6% of Indonesia's coral reefs are in excellent condition, while 24% are in good condition, and approximately 70% are in poor to fair condition (2003 The Johns Hopkins University).
On September 24, 2007, Reef Check (the world's largest reef conservation organization) stated that only 5% of Philippines 27,000 square-kilometers of coral reef are in "excellent condition" : Tubbataha Reef, Marine Park in Palawan, Apo Island in Negros Oriental, Apo Reef in Puerto Galera, Mindoro, and Verde Island Passage off Batangas. Philippine coral reefs is 2nd largest in Asia.[31]
General estimates show approximately 10% of the coral reefs around the world are already dead.[32][33]Problems range from environmental effects of fishing techniques, described above, to ocean acidification.[34] Coral bleaching is another manifestation of the problem and is showing up in reefs across the planet.
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
African and Asian dust outbreaks
Dust from the Sahara moving around the southern periphery of the subtropical ridge moves into the Caribbean and Florida during the warm season as the ridge builds and moves northward through the subtropical Atlantic. Dust can also be attributed to a global transport from the Gobi and Taklamakan deserts across Korea, Japan, and the Northern Pacific to the Hawaiian Islands.[25] Since 1970, dust outbreaks have worsened due to periods of drought in Africa. There is a large variability in the dust transport to the Caribbean and Florida from year to year;[26] however, the flux of dust is greater during positive phases of the North Atlantic Oscillation.[27] Dust events have been linked to a decline in the health of coral reefs across the Caribbean and Florida, primarily since the 1970s.[28] Studies have shown that corals can incorporate dust into their skeletons as identified from dust from the 1883 eruption of Krakatoa in Indonesia in the annular bands of the reef-building coral Montastraea annularis from the Florida reef tract.[29] The relative abundance of chemical elements, particularly metals, has been used to distinguish soil derived from volcanic dust from mineral dust.[30]
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Ocean acidification
Main article: Ocean acidification
The decreasing ocean surface pH is of increasing long-term concern for coral reefs.[20] Increased atmospheric CO2 increases the amount of CO2 dissolved in the oceans.[21] Carbon dioxide gas dissolved in the ocean reacts with water to form carbonic acid, resulting in ocean acidification. Ocean surface pH is estimated to have decreased from approximately 8.25 to 8.14 since the beginning of the industrial era,[22] and it is estimated that it will drop by a further 0.3 - 0.4 units by 2100 as the ocean absorbs more anthropogenic CO2.[23] Under normal conditions, the conditions for calcium carbonate production are stable in surface waters since the carbonate ion is at supersaturating concentrations. However, as ocean pH falls, so does the concentration of this ion, and when carbonate becomes under-saturated, structures made of calcium carbonate are vulnerable to dissolution. Research has already found that corals experience reduced calcification or enhanced dissolution when exposed to elevated CO2.[24]
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Bleaching
Main article: Coral bleaching
During the 1998 and 2004 El Niño weather phenomena, in which sea surface temperatures rose well above normal, many tropical coral reefs were bleached or killed. Some recovery has been noted in more remote locations, but global warming could negate some of this recovery in the future. High seas surface temperature (SSTs) coupled with high irradiance (light intensity), triggers the loss of zooxanthellae, a symbiotic algae, and its dinoflagellate pigmentation in corals causing coral bleaching. Zooxanthellae provide 95% of the energy to the coral host.
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Dynamite fishing
Dynamite fishing is another extremely destructive method that fishermen use to harvest small fish. Sticks of dynamite, grenades, or home-made explosives are lit or activated and thrown in the water. Once the dynamite goes off the explosion brings about an underwater shockwave, causing the internal organs of fish to liquefy, killing them almost instantly. A second blast is often set off after the first to kill any larger predators that are attracted to the initial kill of the smaller fish. This method of fishing not only kills the fish within the main blast area, but also takes the lives of many reef animals that are not edible or wanted. Also, many of the fish do not float to the surface to be collected, but sink to the bottom. The blast also kills the corals in the area, eliminating the very structure of the reef, destroying the habitat for fish and other animals important for the maintenance of a healthy reef. Areas that used to be full of coral become deserts, full of coral rubble, dead fish and little else after dynamite fishing.[18][19] With dynamite fishing especially around the Maldives in the Indian Ocean, have caused a vast majority of problems. With the rising sea level already the coral reefs act as a natural defence against flooding. With the dynamite fishing, the coral reefs are destroyed making the islands more vulnerable to flooding.
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Threats
Bioerosion (coral damage) such as this may be caused by coral bleaching.
Bioerosion (coral damage) such as this may be caused by coral bleaching.[11]
Human activity may represent the greatest threat to coral reefs living in Earth's oceans. In particular, pollution and over-fishing are the most serious threats to these ecosystems. Physical destruction of reefs due to boat and shipping traffic is also a problem. The live food fish trade has been implicated as a driver of decline due to the use of cyanide and disaster for peoples living in the tropics. Hughes, et al, (2003), writes that "with increased human population and improved storage and transport systems, the scale of human impacts on reefs has grown exponentially. For example, markets for fishes and other natural resources have become global, supplying demand for reef resources far removed from their tropical sources."[12]
Currently researchers are working to determine the degree various factors impact the reef systems. The list of factors is long but includes the oceans acting as a carbon dioxide sink, changes in Earth's atmosphere, ultraviolet light, ocean acidification, biological virus, impacts of dust storms carrying agents to far flung reef systems, various pollutants, impacts of algal blooms and others. Reefs are threatened well beyond coastal areas and so the problem is broader than factors from land development and pollution though those are too causing considerable damage.
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Algae and coral reef
Researchers found evidence of algae dominance in locations of healthy coral reefs. In surveys done around largely uninhabited US Pacific islands, algae consists of a large percentage of the surveyed coral locations. [10] The algae population consists of turf algae, coralline algae, and macroalgae.
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Coral reefs support an extraordinary biodiversity; although they are located in nutrient-poor tropical waters. The process of nutrient cycling between corals, zooxanthellae, and other reef organisms provides an explanation for why coral reefs flourish in these waters: recycling ensures that fewer nutrients are needed overall to support the community.
Cyanobacteria also provide soluble nitrates for the coral reef through the process of nitrogen fixation. Corals absorb nutrients, including inorganic nitrogen and phosphorus, directly from the water, and they feed upon zooplankton that are carried past the polyps by water motion.[7] Thus, primary productivity on a coral reef is very high, which results in the highest values per square meter, at 5-10g C m-2 day-1.[8] Producers in coral reef communities include the symbiotic zooxanthellae, coralline algae, and various seaweeds, especially small types called turf algae, although scientists disagree about the importance of these particular organisms.[7]
Coral reefs are home to a variety of tropical or reef fish, such as the colorful parrotfish, angelfish, damselfish and butterflyfish. Other fish groups found on coral reefs include groupers, snappers, grunts and wrasses. Over 4,000 species of fish inhabit coral reefs.[5] It has been suggested that the high number of fish species that inhabit coral reefs are able to coexist in such high numbers because any free living space is rapidly inhabited by the first planktonic fish larvae that occupy it. These fish then inhabit the space for the rest of their life. The species that inhabit the free space is random and has therefore been termed 'a lottery for living space'.[9]
A healthy reef in East Timor on the southern edge of the Banda Sea
A healthy reef in East Timor on the southern edge of the Banda Sea
Reefs are also home to a large variety of other organisms, including sponges, Cnidarians (which includes some types of corals and jellyfish), worms, crustaceans (including shrimp, spiny lobsters and crabs), molluscs (including cephalopods), echinoderms (including starfish, sea urchins and sea cucumbers), sea squirts, sea turtles and sea snakes. Aside from humans, mammals are rare on coral reefs, with visiting cetaceans such as dolphins being the main group. A few of these varied species feed directly on corals, while others graze on algae on the reef and participate in complex food webs.[7][5]
A number of invertebrates, collectively called cryptofauna, inhabit the coral skeletal substrate itself, either boring into the skeletons (through the process of bioerosion) or living in pre-existing voids and crevices. Those animals boring into the rock include sponges, bivalve molluscs, and sipunculans. Those settling on the reef include many other species, particularly crustaceans and polychaete worms.[6]
Due to their vast biodiversity, many governments world-wide take measures to protect their coral reefs. In Australia, the Great Barrier Reef is protected by the Great Barrier Reef Marine Park Authority, and is the subject of much legislation, including a Biodiversity Action Plan.
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Coral reefs around the world are dying at an alarming rate. Lining 60,000 miles of shoreline along 109 countries, reefs and their related fisheries, marshlands and lagoons are vanishing. Home to more than a quarter of all fish species on Earth, an estimated 25% of coral reefs have already disappeared and an estimated 67% of all coral reefs are at risk today. In Southeast Asia, 88% of the reefs are at risk and an estimated more than 90% of the reefs in the Florida Keys have lost their living coral cover since 1975. In a recent study by the crew of our research vessel, Heraclitus, 100% of the corals in Kanton Island lagoon (Phoenix Islands in the remote South Pacific) were observed dead due to global warming. Threatened by pollution, disease, over-fishing, dynamite and cyanide fishing, as well as bleaching most likely caused by rising ocean temperatures, coral reefs are now endangered on a planetary scale. 1
Coral reefs are also an integral part of the earth system biogeochemical processes, including primary production, carbon and calcium storage, and geological formations that facilitate water flow and upwelling. Research has demonstrated that coral reefs respond more quickly than any other ecosystem to environmental changes - even to the slightest changes in water temperature - because of their extremely high sensitivity. For this reason, they are considered an indicator or early warning system for the world's oceans, and perhaps a 'canary in the coal mine' for all of the other ecosystems on Earth.
Despite their importance - both as an ecosystem and barometer for environmental change - relatively little is known about coral reefs today. Remarkably, there is no comprehensive global baseline map of living coral reefs. Scientists do not even know the location of many of the world's reefs, much less their present condition or which species inhabit them. For example, in the Pacific, which has the greatest concentration of coral reefs in the world, it is estimated that 90% of these reefs have never been assessed. 1 Given the paucity of data, it is impossible to measure the rate at which the reefs are disappearing with accuracy. By contrast, scientists know exactly how much rainforest is left and how much is being destroyed every day because there is a very detailed rainforest baseline provided by satellite imagery. A comparable baseline for coral reefs is urgently needed. Until this is achieved, we will not have the information we need to address the coral reef crisis on a global scale.
Source:
http://www.pcrf.org/reefsincrisis.htmla
The reefs in the world NEED OUR help!!
~ Sunday, September 07, 2008 ~
Built over millions of years, coral reefs are home to more than 25 percent of marine species, making them the most biologically diverse of marine ecosystems. Corals produce reefs in shallow tropical and sub-tropical seas and have been shown to be highly sensitive to changes in their environment.
Researchers identified the main threats to corals as climate change and localized stresses resulting from destructive fishing, declining water quality from pollution, and the degradation of coastal habitats. Climate change causes rising water temperatures and more intense solar radiation, which lead to coral bleaching and disease often resulting in mass coral mortality.
Shallow water corals have a symbiotic relationship with algae called zooxanthellae, which live in their soft tissues and provide the coral with essential nutrients and energy from photosynthesis and are the reason why corals have such beautiful colors. Coral bleaching is the result of a stress response, such as increased water temperatures, whereby the algae are expelled from the tissues, hence the term "bleaching." Corals that have been bleached are weaker and more prone to attack from disease. Scientists believe that increased coral disease also is linked to higher sea temperatures and an increase in run-off pollution and sediments from the land.
Researchers predict that ocean acidification will be another serious threat facing coral reefs. As oceans absorb increasing amounts of carbon dioxide from the atmosphere, water acidity increases and pH decreases, severely impacting corals' ability to build their skeletons that form the foundation of reefs.
The 39 scientists who co-authored this study agree that if rising sea surface temperatures continue to cause increased frequency of bleaching and disease events, many corals may not have enough time to replenish themselves and this could lead to extinctions.
"These results show that as a group, reef-building corals are more at risk of extinction than all terrestrial groups, apart from amphibians, and are the most vulnerable to the effects of climate change," said Roger McManus, CI's vice president for marine programs. "The loss of the corals will have profound implications for millions of people who depend on coral reefs for their livelihoods."
Coral reefs harbor fish and other marine resources important for coastal communities. They also help protect coastal towns and other near-shore habitats from severe erosion and flooding caused by tropical storms.
Staghorn (Acroporid) corals face the highest risk of extinction, with 52 percent of species listed in a threatened category. The Caribbean region has the highest number of highly threatened corals (Endangered and Critically Endangered), including the iconic elkhorn coral (Acropora palmata) which is listed as Critically Endangered. The high biodiversity "Coral Triangle" in the western Pacific's Indo-Malay-Philippine Archipelago has the highest proportions of Vulnerable and Near-Threatened species in the Indo-Pacific, largely resulting from the high concentration of people living in many parts of the region.
Corals from the genera Favia and Porites were found to be the least threatened due to their relatively higher resistance to bleaching and disease. In addition, 141 species lacked sufficient information to be fully assessed and were therefore listed as Data Deficient. However, researchers believe that many of these species would have been listed as threatened if more information were available.
The results emphasize the widespread plight of coral reefs and the urgent need to enact conservation measures. "We either reduce our CO2 emission now or many corals will be lost forever," says Julia Marton-Lefèvre, IUCN Director General. "Improving water quality, global education and the adequate funding of local conservation practices also are essential to protect the foundation of beautiful and valuable coral reef ecosystems."
Source:
http://www.sciencedaily.com/releases/2008/07/080710142935.htm
The reefs in the world NEED OUR help!!
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