![]() AIMS scientists together with a team from The University of Western Australia, CSIRO and the University of San Diego have analysed coral cores from the eastern Indian Ocean to understand how the unique coral reefs of Western Australia are affected by changing ocean currents and water temperatures. The research was published today in the international journal Nature Communications. The findings give new insights into how La Niña, a climate swing in the tropical Pacific, affects the Leeuwin current and how our oceans are changing. “Due to the lack of long-term observations of marine climate we used long coral cores, with annual growth bands similar to tree rings, to provide a record of the past. We obtained records of past sea temperatures by measuring the chemical composition of the coral skeleton from year to year. This showed how changing winds and ocean currents in the eastern Indian Ocean are driven by climate variability in the western tropical Pacific Ocean,” said Dr Jens Zinke (Assistant Professor at the UWA Oceans Institute and AIMS-UWA scientist). The long coral records allowed the scientists to look at these patterns of climate variability back to 1795 AD. La Niña events in the tropical Pacific result in a strengthened Leeuwin Current and unusually warm water temperatures and higher sea levels off southwest Western Australia. “A prominent example is the 2011 heat wave along WA’s reefs which led to coral bleaching and fish kills,” said Dr Ming Feng CSIRO Principal Research Scientist. The international team found that in addition to warming sea surface temperatures, sea-level variability and Leeuwin Current strength have increased since 1980. The coral cores also reveal that the strong winds and extreme weather of 2011 off Western Australia are highly unusual in the context of the past 215 years. The authors conclude that this is clear evidence that global warming and sea-level rise is increasing the severity of these extreme events which impact the highly diverse coral reefs of Western Australia, including the Ningaloo Reef World Heritage site. “Given ongoing global climate change, It is likely that future La Niña events will result in more extreme warming and high sea-level events with potentially significant consequences for the maintenance of Western Australia's unique marine ecosystems,” said Dr Janice Lough, AIMS Senior Principal Research Scientist. The researchers used core samples of massive Porites colonies from the Houtman-Abrolhos Islands, the most southerly reefs in the Indian Ocean which are directly in the path of the Leeuwin Current. Using the chemical composition of the annual coral growth bands they were able to reconstruct sea surface temperature and Leeuwin Current for 215 years, from 1795 to 2010. Source: http://www.sciencedaily.com/releases/2014/04/140401102120.htm Reference: J. Zinke, A. Rountrey, M. Feng, S.-P. Xie, D. Dissard, K. Rankenburg, J.M. Lough, M.T. McCulloch. Corals record long-term Leeuwin current variability including Ningaloo Niño/Niña since 1795. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4607
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![]() Long-lived deep-sea corals preserve evidence of a major shift in the open Pacific Ocean ecosystem since around 1850, according to a study by researchers at the University of California, Santa Cruz. The findings, published December 15 in Nature, indicate that changes at the base of the marine food web observed in recent decades in the North Pacific Subtropical Gyre may have begun more than 150 years ago at the end of the Little Ice Age. Deep-sea corals are colonial organisms that can live for thousands of years, feeding on organic matter that rains down from the upper levels of the ocean. The corals' branching, tree-like skeletons are composed of a hard protein material that incorporates chemical signatures from their food sources. As a result, changes in the composition of the growth layers in deep-sea corals reflect changes in the organisms that lived in the surface waters at the time each layer formed. "They're like living sediment traps, recording long-term changes in the open ocean that we can't see any other way," said coauthor Matthew McCarthy, professor of ocean sciences at UC Santa Cruz. Scientists can study sediment cores taken from the ocean floor for clues to past conditions in the oceans, but that approach is not very useful for the most recent millennia. In the open ocean of the North Pacific, sediment accumulates so slowly that the entire Holocene epoch (the past 12,000 years or so) is represented by less than 10 centimeters (4 inches) of sediment that has been stirred up by organisms living on the seafloor. "Even if there were good sediment records, we would never get the level of detail we can get from the corals," McCarthy said. To analyze the coral skeletons, the UCSC researchers combined carbon dating with a novel technique for analyzing nitrogen isotopes in proteins. They were able to reconstruct records over the past 1,000 years indicating that a shift occurred around 1850 in the source of nitrogen feeding the surface waters of the open ocean. As a result of decreasing nitrogen inputs from subsurface water, the phytoplankton community at the base of the food web became increasingly dominated by nitrogen-fixing cyanobacteria, which are able to use the nitrogen gas absorbed by surface waters from the atmosphere. "In the marine environment, the two major sources of nitrogen are dissolved nitrate, which is more concentrated in the subsurface and deep water and is brought to the surface by upwelling, and nitrogen fixation by specialized microorganisms that are like the legumes of the sea," explained first author Owen Sherwood, who worked on the study as a postdoctoral researcher at UCSC and is now at the University of Colorado, Boulder. The shift revealed in the coral record--from an ecosystem supported by nitrate coming up from deeper waters to one supported more by nitrogen-fixing organisms--may be a result of the North Pacific Subtropical Gyre expanding and becoming warmer, with more stable layering of warm surface water over cooler subsurface water. This increased "stratification" limits the amount of nutrients delivered to the surface in nutrient-rich subsurface water. Scientists have observed warming and expansion of the major mid-ocean subtropical gyres in the past few decades and have attributed this trend to global warming. The new study puts these observations in the context of a longer-term trend. "It seems that the change in nitrogen sources, and therefore possibly large-scale shifts in ocean conditions, switched on at the end of the Little Ice Age and it is still continuing today," McCarthy said. A key innovation in nitrogen isotope analysis was crucial to this study. Nitrogen-15 is a minor stable isotope of nitrogen, and the ratio of nitrogen-15 to nitrogen-14 is widely used to trace different sources of nitrogen. The nitrogen fixed by cyanobacteria in surface water, for example, has a different isotope ratio from the nitrates in deep ocean water. The isotope ratio also changes as organisms eat each other and nitrogen moves through the food web, with organisms at the base of the web having lower ratios than organisms at higher "trophic levels." Thus, two independent factors--the trophic level and the original source of the nitrogen--determine the nitrogen isotope ratio in an organism. McCarthy's lab developed a technique that can separate these two factors by analyzing individual amino acids--the building blocks of proteins. It turns out that the isotope ratios of some amino acids remain unchanged as they move up the food web, while other amino acids become enriched in nitrogen-15 with each trophic transfer. "Amino acid analysis decouples the two effects so we can see their relative magnitudes," McCarthy said. "What we're seeing in the central Pacific is a major shift at the base of the food web." The extent of the change is dramatic: a 17 to 27 percent increase in nitrogen-fixation since about 1850, after almost a millennium of relatively minor fluctuations. "In comparison to other transitions in the paleoceanographic record, it's gigantic," Sherwood said. "It's comparable to the change observed at the transition between the Pleistocene and Holocene Epochs, except that it happens an order of magnitude faster." These and other recent results are changing scientists' notions about the stability of open ocean gyres such as the North Pacific Subtropical Gyre, which is the largest contiguous ecosystem on the planet. These open ocean gyres were once considered relatively static, nutrient-deprived "deserts." In the 1980s, however, scientists began regularly monitoring oceanographic conditions at deep-water station ALOHA near Hawaii, revealing a surprising amount of variability. "Instead of relatively constant ocean deserts, time-series data has shown dynamic decadal-scale changes," McCarthy said. "Our new records from deep-sea corals now show that the decadal-scale changes are really only small oscillations superimposed on a dramatic long-term shift at the base of the Pacific ecosystem. This long-term perspective may help us better predict the effects of global warming on open ocean regions." The new findings also suggest a new interpretation of data from other researchers showing changes in nitrogen isotopes in the bones of seabirds. A recent study of Hawaiian petrel bones using bulk nitrogen isotope data attributed the change to shifts in the length of open ocean food chains, possibly induced by overfishing (forcing petrels to feed lower on the food chain). In fact, the compound-specific data strongly imply that isotopic changes on all trophic levels are more likely due to the long-term shift in nitrogen sources at the base of the food web, McCarthy said. Coauthor Tom Guilderson, who is affiliated with UCSC and Lawrence Livermore National Laboratory, has been collecting deep-sea corals for more than a decade to study them for clues to past oceanographic and environmental conditions. He teamed up with McCarthy to initiate this project. In addition to McCarthy, Guilderson, and Sherwood, the coauthors of the paper include UCSC graduate students Fabian Batista and John Schiff. Coral samples were collected by the Hawaiian Undersea Research Lab's Pisces V submersible, with funding from the National Oceanic and Atmospheric Administration (NOAA) and the National Geographic Society. The bulk of this research was funded by the National Science Foundation. Source: http://www.eurekalert.org/pub_releases/2013-12/uoc--dcr121113.php ![]() Posted by Caron Lett-York on October 30, 2013 As threats to coral reefs grow, scientists are taking a nanoscale look at how they form skeletons. Coral produce limestone—calcium carbonate—skeletons that build up over time into vast reefs. The skeleton’s role is to help the living biofilm move towards light and nutrients. For a recent study, researchers looked at the smallest building blocks that can be identified—a microstructure called spherulites—by making a thin cross-section—less than 100 nanometers—of a skeleton crystal. They then used transmission electron microscopy (TEM) to analyze the crystals. Day and night The TEM micrographs revealed three distinct regions: randomly orientated granular, porous nanocrystals; partly oriented nanocrystals, which were also granular and porous; and densely packed aligned large needle-like crystals. These different regions could be directly correlated to times of the day: at sunset, granular and porous crystals are formed, but as night falls, the calcification process slows down and there is a switch to long aligned needles. “Coral plays a vital role in a variety of eco-systems and supports around 25 percent of all marine species. In addition, it protects coastlines from wave erosion and plays a key role in the fisheries and tourism industries,” says Renée van de Locht, a PhD student in the physics department at the University of York and corresponding author of the study. “However, the fundamental principles of coral’s skeleton formation are still not fully understood. “It has been suspected for some time that the contrast bands seen in crystals in optical images were daily bands. Through our research we have been able to show what the crystals actually contain and the differences between day and night crystals.” The research concentrated on three species of tropical, reef-building coral: Porites lobata, Siderastrea sidereal, and Montastrea annularis. “Although we knew there was a difference between day and night crystals, we’ve actually been able to see the evolution from granular to aligned needles and to find out much more information about the phase, orientation and size of the aragonite crystals,” says lead investigator Roland Kröger. The first phase of the research was reported in the Journal of Structural Biology earlier this year. The Engineering and Physical Sciences Research Council and an International Seedcorn award from the University of York funded the work. Source: http://www.futurity.org/night-coral-shift-grow-skeletons/ ![]() Scanning electron microscopy images of a Porites lobata coral. The top image shows the surface, from which living tissue was removed. The bottom image is an etched cross-section surface showing a spherulite; with a granular crystal center and needle-like crystal bundles radiating outwards. Spherulites form the building blocks of coral skeletons. (Credit: Renée van de Locht/Roland Kröger and Wikimedia Commons)
![]() Por Agencia EFE Sídney, Australia - Los corales producen una sustancia química fétida que los protege del aumento de la temperatura de los océanos y además juegan un papel clave en la regulación de su entorno, según un estudio divulgado ayer. Un equipo científico descubrió, por primera vez, que un organismo animal como los corales producen dimetilsulfoniopropionato (DMSP), que tiene el olor característico de los océanos, según un comunicado del Instituto Australiano de Ciencias Marinas (AIMS). "Anteriormente se pensaba que las largas concentraciones de DMSP que emanaban los arrecifes coralinos provenían de las algas simbióticas", dijo el jefe de la investigación, Jean-Baptiste Raina, del AIMS y la Universidad James Cook. Los corales aumentan la producción de esta sustancia cuando la temperatura del océano aumenta. Esta sustancia y sus derivados actúan como antioxidantes y protegen a los tejidos coralinos contra el estrés ambiental causado por la alta radiación solar. El DMSP también crea una especie de nubes o capas alrededor del coral que reflejan hacia la atmósfera los rayos solares lo que evita un mayor calentamiento de la superficie del mar. Por su lado, otra investigadora, Cherie Motti, descubrió que los corales también producían este olor al abrir un envase que contenía muestra de estos cnidarios. "Me dieron esta muestra y cuando abrí el envase sentí ese olor del océano y me impactó porque no lo esperaba", comentó la científico a la cadena local ABC. La química advirtió que si somete a los corales a una gran cantidad de situaciones estresantes, éstos no podrán producir con rapidez este compuesto de sulfuro que les protege contra el "blanqueamiento" o decoloración por el aumento de la temperatura del agua. Si las condiciones del entorno se vuelven más adversas, el coral tendrá menos posibilidades de sobrevivir. La Gran Barrera de Coral en Australia, que alberga 400 tipos de coral, 1,500 especies de peces y 4,000 variedades de moluscos, comenzó a deteriorarse en la década de 1990 por el doble impacto del calentamiento del agua del mar y el aumento de su acidez debido a una mayor presencia de dióxido de carbono en la atmósfera. Recurso: http://www.elnuevodia.com/loscoralesproducensustanciaparaprotegersedelcalor-1628480.html ![]() A new study, published in Nature Communications, has found that one of the major reasons behind the loss of coral reefs can be found on what is happening on land. After looking a deforestation rates and scenarios, the scientists were able to find a correlation between deforestation and change in coral reefs. “The findings are very relevant for Australia since intense land use and past deforestation have transformed the river catchments tremendously and are seen as a major threat to coral reefs in the Great Barrier Reef and elsewhere,” said Dr Jens Zinke, of UWA’s Oceans Institute, in a news release from the University of Western Australia. “Managing hinterland land use is the major action needed to buy time for corals growing near rivers.” The coral reefs, which habitat a quarter of marine wildlife, are severely endangered and have seen a steady decline in the past decades around the world. In Australia, for example, the Great Barrier Reef has had a 50 percent decline in the last 50 years. What’s more, scientists have estimated that all the coral reefs in Southeast Asia could disappear in this century resulting in a 80 percent decline in food availability. But now there’s some bad news for the coral reefs in the Caribbean. According to The Guardian, a new report by the International Union for Conservation of Nature (IUCN) reveals the devastating findings of the most up-to-date survey of reefs in the region: Only 8 percent of the reef have live coral. In fact, the only area in the Caribbean that is not showing such morbidity are remote areas in the Netherlands Antilles and Cayman Islands, where 30% of live coral still remains. Think this is no big deal? Consider this: It has been estimated that in the 1970s, this same Caribbean reefs had over 50 percent of live coral. The Guardian reports: Coral reefs are a particularly valuable part of the marine ecosystem because they act as nurseries for younger fish, providing food sources and protection from predators until the fish have grown large enough to fend better for themselves. They are also a source of revenue from tourism and leisure. Carl Gustaf Lundin, director of the global marine and polar programme at the International Union for Conservation of Nature (IUCN), which published the research, said: “The major causes of coral decline are well known and include overfishing, pollution, disease and bleaching caused by rising temperatures resulting from the burning of fossil fuels. Looking forward, there is an urgent need to immediately and drastically reduce all human impacts [in the area] if coral reefs and the vitally important fisheries that depend on them are to survive in the decades to come.” This news comes just month after a recently published scientific paper (published in the journal Science) which found that the rate at which the ocean is acidifying is faster now than it has ever been in the last 300 million years. Ocean acidification is a phenomenon related to rising carbon dioxide levels in the atmosphere that make it difficult for creatures to build their shells and skeletons. The study, led by Columbia University paleoceanographer Bärbel Hönisch, analyzed existing evidence from decades of research on the earth’s geologic history and has concluded that “we are entering an unknown territory of marine ecosystem change.” It does not take a huge stretch of one’s imagination to accept that the causes behind this catastrophic statistic are human activity such as pollution, overfishing, and even ocean acidification. And while there are many global efforts to preserve the coral–including those by Mexico-based artist and ‘eco-sculptor’ Jason de Caires Taylor who is creating an artificial reef by placing pH-neutral cement sculptures underwater that allows organisms (i.e., sponges, starfish and tunicates) to latch on and form coral–one has to ask: Is it enough? Source: http://www.greenerideal.com/science/0618-save-coral-underwater-by-stopping-deforestation-on-land/ ![]() The USS Guardian, a U.S. Navy minesweeper (Reuters / Handout) he Philippines government has fined the US Navy for unlawfully entering and damaging a World-Heritage listed coral reef aboard the USS Guardian, even after receiving radio warnings by park rangers to avoid the reef. Penalties of unauthorized entry to the Tubbataha Reef are severe, and include a maximum penalty of one-year imprisonment and a fine of 300,000 pesos (about $7,300). The Philippine government has decided to fine the US Navy, but will not be sending anyone to prison, according to information obtained by the Agence France-Presse. Ever since the USS Guardian damaged the protected reef on Jan. 17, Philippines have expressed growing anger over the perceived carelessness of the US. A government-led board that manages the reef took several days to assess the destruction to its reef and resources and decide on the penalty. Jose Lorenzo Tan, a member of the board, refused to discuss the amount of the fine the US Navy will be forced to pay, but confirmed that there would be no jail time. Angelique Songco, head of the Philippines government’s Protected Area Management Board, told the Huffington Post that the government typically imposes fines of about $300 per square meter of damaged coral. The World Wide Fund for Nature Philippines estimates that at least 10 meters (11 yards) of the 68-meter (74-yard) reef have been damaged. On Jan. 17, the USS Guardian, an American minesweeper, went aground the coral reef, even after receiving radio complaints from park rangers assigned to warn oncoming ships of the World Heritage-listed site’s location. After park rangers contacted the USS Guardian, the ship captain told them to direct their complaints to the US embassy instead. The US Navy then continued along their route, going aground against the Tubbataha Reef and getting stuck. The US Navy released a statement after the incident, blaming the slip-up on bad weather, wind and waves, and promising that some of its personnel will remain aboard the USS Guardian to help free the ship from the coral it was stuck on and to minimize the environmental damage. The US has long planned to increase its military presence in the Philippines in order to counter China’s growing influence in the region. Last month, the Obama administration began to significantly increase its number of troops, aircraft and ships that rotate through the island nation. The US has also provided the country with financial assistance and signed a five-year joint US-Philippine military exercise plan. The US Navy also visits the Philippine ports to refuel its ship and allow its forces to rest and relax. But while the administration has tried to keep up good relations with the Philippines and gain a strong presence in the region, its mistake on the World Heritage-listed coral reef upset many locals and may cause a setback. The USS Guardian is now grounded on the south atoll of the Tubbatha Reef. The Phillipine Coast Guard will attempt to remove the ship from its dangerously close location to the protected reef and will continue to assess the environmental damage. See Video Source: http://rt.com/usa/news/us-navy-coral-reef-523/ ![]() A high level of coral cover doesn’t always mean a high level of species diversity By: Zoe Richards The health and productivity of coral reefs is rapidly declining. Hard corals are the principal builders of coral reef ecosystems; however they are struggling to survive due to pollution, catchment clearing and climate change. The task of curtailing these declines is immense. To protect coral reef ecosystems, a portfolio of management approaches are needed. This includes Commonwealth and State leadership and community participation. Most importantly, management actions must be based upon pragmatic science. Currently the health of coral reefs is reported in terms of the level of coral cover. It is assumed that a reef with high cover is healthier than one with low cover. This information ultimately influences the selection of marine reserves. However, new research shows that reefscape metrics such as coral cover are not linearly related to richness of a coral species. This means that if a reef is designated as healthy and consequently given an elevated level of protection (for example, made a no-take zone) because it has a high level of coral cover, the biodiversity benefit of protecting this reef may not be as high as first expected. Moreover, results of this study show that the relationship between coral cover and coral diversity is far from simple. Coral biodiversity actually peaks at intermediate levels of coral cover. This finding is not unusual, considering coral communities can be dominated by a single or small number of species that can reach an incredibly high level of cover. This can occur when a community is in an early phase of recovery after a disturbance or when there have been no disturbances for a long time. Alternatively, it is quite common for coral communities to have a large number of species that occur as small, sparse colonies. Therefore even if coral cover is not high, there is a high level of diversity. If coral biodiversity is high, this benefits all of the fish, crustaceans and other associated marine life. Knowing about the lack of a positive linear relationship between coral cover and coral biodiversity is important information for coral reef managers. This is because biodiversity lies at the core of ecosystem health, productivity and functioning. Especially on disturbed reefs, a large pool of species is required to sustain ecosystem structure and function. Evidence is mounting that individual species are important to ecosystem resilience and that even small changes in diversity can have significant impacts on ecosystem function. One of the most ominous consequences of reef degradation is the loss of biodiversity. Despite this, in most reef regions there is little information about species occurrences, or about species' responses to management and environmental change. Moreover, financial and logistical constraints mean that proxy measures are not necessarily used in coral reef monitoring. The best proxies are those that are reliable, easily quantified and documented as a simple linear function. Results presented in this study indicate that while coral cover performs poorly as a measure of species richness; genus diversity performs well because it is strongly and linearly associated with species richness. This suggests that collecting data on coral genus diversity would be a valuable addition to coral reef monitoring programs. Ultimately the loss of biodiversity is irreversible and the ecosystem effects are unpredictable. The ability to detect and monitor biodiversity is vital if we are to protect it. Source: http://theconversation.edu.au/a-lot-of-coral-doesnt-always-mean-high-biodiversity-10548 ![]() Cold-water corals face an uncertain future as increasing CO2 in the atmosphere changes the chemistry of our oceans. Laura Wicks set sail on the Changing Oceans Expedition to find out how these amazing animals are likely to fare. Hidden deep in all the world's oceans are the vast mounds and reefs of cold-water corals. They grow much more slowly than their tropical counterparts but can still extend over huge areas: reefs of Lophelia pertusa off Norway cover around 2000km2 - more than tropical reefs in the Seychelles, Belize or Mozambique. The corals build their skeletons from calcium carbonate dissolved in the seawater, creating complex 3D structures that persist even after the animal itself has died. These skeletons support thousands of species, including many that we eat. But the life of these hidden corals is under threat. The amount of CO2 in the atmosphere has increased exponentially since the Industrial Revolution and much of it is dissolving into the oceans, slowly increasing the acidity of seawater. The pH of the sea is currently about 8.1, but this is predicted to drop by about 0.3 pH units by 2100. It doesn't sound like much, but this small change can have huge implications for marine organisms that rely on calcium carbonate, like corals, shell-producing animals and calcareous algae. This is because the increasing concentration of dissolved CO2 in the oceans decreases the carbonate saturation of the water, so there is less carbonate available for coral skeletons and shells. This acidification of the oceans, often referred to as 'the other CO2 problem', may be the biggest threat facing marine calcifying organisms today. In May 2012, I set sail for the North Atlantic on the RRS James Cook, part of an international team of scientists on the Changing Oceans Expedition. Our mission was to examine the potential impact of ocean acidification and warming on cold-water coral reefs and the creatures they support. In our four weeks at sea we visited a range of cold-water coral sites, from the 'shallow' reefs of Mingulay in the Outer Hebrides (around 130m deep), dominated by Lophelia pertusa, to the Logachev Mounds, west of Ireland; nearly 1000m deep and spectacular with both Lophelia pertusa and Madrepora oculata. We don't know a great deal about either species of coral, or the ecosystems they form, because they are so inaccessible - you can't just dive in and explore them like you can in the tropics. Before we could even think about collecting samples we had to find the reefs. To do this we used advanced acoustic techniques, such as multibeam and sidescan sonar, that use sound waves to create an image of the seabed from which we could pick out possible mounds of coral. The next step was to send down our robot, the Remotely Operated Vehicle (ROV) Holland I, to take a closer look. During each ROV dive the excitement in the lab was palpable. The ROV's high-definition cameras beamed up spectacular images of the reefs beneath us. Fish darted across the screen and unusual sponges and crabs came into view, causing a buzz as we tried to work out exactly what they were. But we weren't just there to watch. As part of 'Team Coral', I carried out short-term experiments to see what effect ocean warming and acidification have on the growth and overall health of the corals. Using samples carefully collected by the ROV's robotic arms, we kept Lophelia pertusa and Madrepora oculata in specially designed tanks for the duration of the cruise. We manipulated the temperature and CO2 levels in these 'mini-oceans' to mimic one possible set of future conditions, in this case a 3°C increase in temperature and a near-doubling of atmospheric CO2. We then measured the respiration and growth rates of the corals over three weeks. My team-mates looked at how other aspects of the corals' biology responded to their changing environment, including microbial communities and protein expression. All of an animal's biological processes, such as growth and respiration, are controlled by proteins, so changes in the concentration of various proteins give us a clue as to how processes like calcification may respond to increased temperature and ocean acidification in the future. Along with longer-term experiments under way at Heriot-Watt University, these will help us to work out how the corals will respond to global climate change - whether they can adapt, or whether ultimately it will be impossible for them to survive. Alongside the ROV campaign, a host of other activities took place out at sea. One was the deployment of the CTD and SAPS. CTD stands for conductivity, temperature and depth, which this particular instrument measures at the bottom of the ocean. Attached to the CTD frame we had a SAPS - Stand Alone Pumping System - which is a big pump with a filter and timer. We use the SAPS to look at the amount of particulate organic carbon (coral food) that is reaching the reefs. When it reaches the seabed the pump switches on and records how much water flows through its filters, which capture the organic carbon. Back in the lab, we analyse the amount of carbon on the filters and the water flow, to calculate how much food the corals have access to. Combined with surveys of the reef and CTD data, this information can help us understand why the corals live where they do, and how any future changes in climate and currents may affect these ecosystems. Four weeks at sea passed by in a flash, and everyone on board collected a wealth of information. Now we're all back on dry land, it's time to process samples, extract data and try to understand what the future holds for these cold-water creatures as our oceans change. Source: http://planetearth.nerc.ac.uk/features/story.aspx?id=1313&cookieConsent=A#.ULTGtpd0gLc.facebook |
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