Study: First Ever Evidence Of Natural Disease Resistance In Tropical Corals

Underwatertimes.com News ServiceNovember 21, 2008 18:33 EST Boston, Massachusetts -- In recent years, tropical coral reefs have become drastically altered by disease epidemics. In a new study published by PLoS ONE, lead author Steven V. Vollmer, assistant professor of biology at the Marine Science Center at Northeastern University, finds that acroporid corals listed on the US Endangered Species List due to epidemics of White Band Disease can recover because up to six percent of the remaining corals are naturally resistant to the disease. This is the first evidence of natural disease resistance in tropical reef corals.
The Carribean-wide mass die-offs of acroporid corals and urchins have been major contributors to the rapid decline of coral reefs. Reef-building corals have generally been susceptible to the global rise in marine diseases. As foundation species on tropical reefs, the impacts of White Band Disease (WBD) and other coral diseases have rippled throughout the ecosystem. Recuperation of these formerly dominant corals has been slow.Despite its extreme impacts, much about the causes and ecology of WBD remains poorly understood.
“Understanding disease resistance in these corals is a critical link to restoring populations of these once prevailing corals throughout their habitat,” said Vollmer. “Our study has shown that there are disease resistant corals, which means that these corals and thus the shallow water reefs of the Caribbean can be recovered.”
The study, titled “Natural Disease Resistance in Threatened Staghorn Corals” examines the potential for natural resistance to WBD in the staghorn coral. Using genotype information and field monitoring of WBD, the study found that six percent of staghorn coral genotypes are naturally resistant to WBD.
These resistant staghorn coral strains might explain why pockets of coral have been able to survive the WBD epidemic. Identifying, protecting and farming these disease resistant corals provides a clear avenue to recover these corals.

http://www.underwatertimes.com/news.php?article_id=62017531098

52 whales die in mass stranding in Australia: report

Fifty-two pilot whales have died after a mass stranding on Tasmania's northwest coast, the Australian Broadcasting Corporation reported Saturday.
Thirteen whales were still alive on Anthony's Beach at Stanley on the island south of the Australian mainland, and wildlife rangers and volunteers were trying to stabilise them, the broadcaster said.
"People are moving water around them, people are stopping them from drying and stopping them from getting sunburnt because their biggest problem is they get overheated," said Parks and Wildlife official Chris Arthur.
"Then we're going to try and move some if we can on to trailers so we can move them in to deeper water."
Pilot whales are members of the dolphin family but are considered by experts to behave more like whales.
A number of theories have been put forward as to why whales strand themselves, but the phenomenon remains a subject of scientific debate.

http://www.france24.com/en/20081122-52-whales-die-mass-stranding-australia-report

Study: Ocean Growing More Acidic; '10 Time Faster' Than Models Predicted

Underwatertimes.com News ServiChicago, Illinois -- University of Chicago scientists have documented that the ocean is growing more acidic faster than previously thought. In addition, they have found that the increasing acidity correlates with increasing levels of atmospheric carbon dioxide, according to a paper published online by the Proceedings of the National Academy of Sciences on Nov. 24.
"Of the variables the study examined that are linked to changes in ocean acidity, only atmospheric carbon dioxide exhibited a corresponding steady change," said J. Timothy Wootton, the lead author of the study and Professor of Ecology and Evolution at the University of Chicago.ceNovember 24, 2008 17:55 EST The increasingly acidic water harms certain sea animals and could reduce the ocean's ability to absorb carbon dioxide, the authors said. Scientists have long predicted that higher levels of atmospheric carbon dioxide would make the ocean more acidic. Nevertheless, empirical evidence of growing acidity has been limited.
The new study is based on 24,519 measurements of ocean pH spanning eight years, which represents the first detailed dataset on variations of coastal pH at a temperate latitude—where the world's most productive fisheries live.
"The acidity increased more than 10 times faster than had been predicted by climate change models and other studies," Wootton said. "This increase will have a severe impact on marine food webs and suggests that ocean acidification may be a more urgent issue than previously thought, at least in some areas of the ocean."
The ocean plays a significant role in global carbon cycles. When atmospheric carbon dioxide dissolves in water it forms carbonic acid, increasing the acidity of the ocean. During the day, carbon dioxide levels in the ocean fall because photosynthesis takes it out of the water, but at night, levels increase again. The study documented this daily pattern, as well as a steady increase in acidity over time.
"Many sea creatures have shells or skeletons made of calcium carbonate, which the acid can dissolve," said Catherine Pfister, Associate Professor of Ecology and Evolution at the University of Chicago and a co-author of the study. "Therefore, the increased acidity of the ocean could interfere with many critical ocean processes such as coral reef building or shellfish harvesting."
Conducted at Tatoosh Island in the Pacific Ocean off the coast of Washington, the study documented that the number of mussels and stalked barnacles fell as acidity increased. At the same time, populations of smaller, shelled species and noncalcareous algae increased.
"Models revealed strong links between the dynamics of species living on the shore and variation in ocean pH," Wootton said. "The models project substantial shifts in the species dominating the habitat as a consequence of both the direct effects of reduced calcification and indirect effects arising from the web of species interactions."
The study, "Dynamical Patterns and Ecological Impacts of Declining Ocean pH in a High-Resolution Multi-Year Dataset," will be published in the Dec. 2 issue of PNAS. The third co-author, James Forester, was at the University of Chicago's Department of Ecology and Evolution but is currently at Harvard University.
"To date there is a lack of information about how the ocean carbon cycle has changed in recent years," Pfister said. "Atmospheric carbon dioxide concentrations will continue to increase, and our work points to the urgent need to better understand the ocean pH changes that this is likely to drive as well as how these changes will affect marine life."

http://www.underwatertimes.com/news.php?article_id=11072490385

Alien-like Squid Filmed at Ultra-Deep Oil-Drilling Site

Kelly Hearnfor National Geographic News
November 24, 2008A mile and a half (two and a half kilometers) underwater, a remote control submersible's camera has captured an eerie surprise: an alien-like, long-armed, and—strangest of all—"elbowed" Magnapinna squid.

Video is at the link below

http://news.nationalgeographic.com/news/2008/11/081124-giant-squid-magnapinna.html

200 whales trapped in Canada's Arctic 'must be killed'

From correspondents in Ottawa
November 22, 2008 07:42amAT least 200 narwhal whales in Canada's Arctic, trapped by winter ice and facing starvation or suffocation, must be culled, officials say.
Hunters from the village of Pond Inlet on Baffin Island discovered the animals trapped near Bylot Island, about 17 kilometres from Pond Inlet, on November 15.
The local hunters are allowed to harvest only 130 whales each year for food, according to standards set by the federal department of Fisheries and Oceans.
But department spokesman Keith Pelley said: "It's unlikely the animals are going to survive the winter, so the hunters have been given authorisation to cull them."
The hunters have been on the ice slaughtering the whales since Thursday and are likely to accomplish their task over the coming days, he said.
Narwhal are found mostly in the Arctic circle, and are renowned for their extraordinarily long tusk, which is actually a twisted incisor tooth that projects from the left side of its upper jaw and can be up to three metres long.
"A couple of weeks ago, when the ice was still moving, there were quite a few narwhal seen out there in the open water," Jayko Allooloo, chairman of the Pond Inlet hunters and trappers organisation, told public broadcaster CBC.
"About a week later, they're stuck."
Community elders and officials feared the whales would die from a lack of oxygen as the ice grew thicker around them, Keith Pelley explained. There are about a dozen areas of open waters where they could come up for air, but it is a tight squeeze for them.

http://www.news.com.au/adelaidenow/story/0,22606,24688959-5005962,00.html

Climate Change Seeps Into The Sea As The Good News Has Turned Out To Be Bad

Underwatertimes.com News ServiceOctober 24, 2008 17:53 EST Washington, D.C. -- The ocean has helped slow global warming by absorbing much of the excess heat and heat-trapping carbon dioxide that has been going into the atmosphere since the start of the Industrial Revolution.
All that extra carbon dioxide, however, has been a bitter pill for the ocean to swallow. It's changing the chemistry of seawater, making it more acidic and otherwise inhospitable, threatening many important marine organisms. Scientists call ocean acidification "the other carbon dioxide problem." They warn that because it causes such fundamental changes in the ocean, it could impact millions of people who depend on the ocean for food and resources. "The growing amount of carbon dioxide in the ocean could have a bigger effect on life on Earth than carbon dioxide in the atmosphere," says JPL's Charles Miller, deputy principal investigator for NASA's new Orbiting Carbon Observatory, scheduled to launch next January.
The ocean takes in and stores most of the heat from the sun that is deposited at Earth's surface -- heat that would otherwise be melting land ice and warming the atmosphere. The ocean also absorbs about one third of the carbon dioxide that humans now put into the air. The rest is taken up by terrestrial vegetation and soils or remains in the atmosphere, increasing the greenhouse effect.
"The ocean surface acts like a sponge to soak up excess carbon dioxide from the atmosphere," says Scott Doney, a senior scientist in marine chemistry at the Woods Hole Oceanographic Institution in Woods Hole, Mass. Much of the extra dissolved carbon is in the ocean’s upper few thousand feet. However, at high latitudes, surface water quickly cools, becomes saltier and denser and sinks, carrying the dissolved carbon to some of the deepest parts of the ocean.
Mix carbon dioxide with water and the result is carbonic acid. After that first simple chemical reaction comes a slightly more complicated series of changes in seawater chemistry. The final outcome is a lowering of the ocean's pH -- meaning the ocean is more acidic, and, ironically, a reduction in a particular form of carbon -- carbonate ion -- that many marine organisms need to make shells and skeletal material. The lower pH and lack of carbonate ion have serious consequences for life in the ocean.
Carbon, Carbon Everywhere, but Not the Right Kind to Use
Closest to the atmospheric source of excess carbon dioxide, the ocean’s surface waters are the first to show the effects of acidification. Since the beginning of the industrial era, the pH of surface waters has decreased slightly but significantly from 8.2 to 8.1, and it continues to decrease. Scientists project the pH of surface water will decrease by the year 2100 to a level not seen on Earth over the past 20 million years, if not longer.
Likely casualties of ocean acidification are the marine plants and animals that use carbonate to form hard shells or other structures. These include mollusks like clams and oysters, and reef-building corals. Not only does ocean acidification limit their access to the carbonate they need for building material, it could become severe enough to dissolve existing coral structures and the shells of living organisms.
Since most corals live in shallow waters, coral reefs, some of the most biologically diverse places on Earth, are particularly vulnerable. “They are already under assault from warming water, over-fishing and habitat degradation,” says Doney. “Environmental stress is leading to more incidents of ‘coral bleaching,’ which occurs when the symbiotic algae that lives inside the coral leaves or dies, and from which reefs often do not recover. Ocean acidification may push corals over the edge.”
Other sensitive areas are the Southern Ocean and the subpolar North Pacific, where acidification threatens to unravel important food chains by making life difficult for a small marine snail called a pteropod. It’s a favorite food of small fishes, which, in turn, support larger fishes, penguins, whales and seabirds. Ocean acidification strips seawater of the carbonate ion that pteropods need to build new shells, and it also damages their existing ones.
There will be some winners and losers, says Doney, as the effects of growing ocean acidification are felt. “Although we don’t know exactly how many species depend on pteropods, clams, oysters, mussels or other shelled organisms for food, or on coral reefs for critical habitat, it’s clear that ocean acidification will cause a wholesale alteration of some marine ecosystems in ways we can’t predict,” he explains.
History isn’t much of a guide. While there have been times in Earth’s past when the ocean was more acidic than now, most environmental changes occurred at a considerably slower pace than today. “At the rates of climate change and ocean acidification we’re seeing now, many organisms may be not able to keep up,” Doney says.
That Sinking Feeling
Much of the carbon now in the air will find its way into the ocean with predictable results. "Even if we stopped adding carbon dioxide to the atmosphere today, ocean acidification will continue to increase,” says Doney. “What marine fisheries and coral reefs will look like 100 years from now is a big question. We need to know how much carbon dioxide is being taken up, more about the gas exchange between the ocean and the atmosphere, and how this mechanism is affected by climate change.”
NASA’s new Orbiting Carbon Observatory will help provide some of the answers after it is launched in January 2009. A NASA Earth System Science Pathfinder mission, it will make precise measurements of atmospheric carbon dioxide on a global scale.
The Orbiting Carbon Observatory will help identify carbon dioxide sources and sinks -- things that absorb and store carbon -- on land and in the ocean and show how they vary over time. Researchers will be able to combine mission data with numerical models to estimate global patterns of the exchange of carbon dioxide from the ocean and atmosphere.
“We’ll have a much better idea about what’s going on over the ocean where measurements have been sparse,” explains Miller. “This is especially true in the Southern Ocean, which we believe is a big sink for carbon dioxide based on existing models.”
While the Orbiting Carbon Observatory may be the newest NASA mission to help address the issue of ocean acidification, NASA has many other projects and missions that provide important information about ocean biology and chemistry that relates directly to this problem. These include NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS), flying on the Terra and Aqua satellites, and the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS). These instruments collect data on ocean color -- a key component of many studies of ocean ecology, plankton and coral reefs. Another example is the recent National Oceanic and Atmospheric Administration and NASA-sponsored Southern Gas Exchange Experiment. During this six-week research cruise, scientists investigated how gases, including carbon dioxide, move between the ocean and the atmosphere in high winds and rough seas.
The really big question is how much longer the ocean can continue to be a sink for atmospheric carbon dioxide before becoming saturated -- a process that may already be under way. The implications for our future climate -- and the ocean -- are immense.

http://www.underwatertimes.com/news.php?article_id=10850324796

Researcher: Coral Reefs Found Growing In The Ice-cold, Ink-black Depths Of The Atlantic

Underwatertimes.com News ServiceNovember 4, 2008 19:08 EST Den Haag, The Netherlands -- Imagine descending in a submarine to the ice-cold, ink-black depths of the ocean, 800 metres under the surface of the Atlantic. Here the tops of the hills are covered in large coral reefs. NIOZ-researcher Furu Mienis studied the formation of these unknown cold-water relatives of the better-known tropical corals.
Furu Mienis studied the development of carbonate mounds dominated by cold-water corals in the Atlantic Ocean at depths of six hundred to a thousand metres. These reefs can be found along the eastern continental slope from Morocco to Norway, on the Mid-Atlantic Ridge and on the western continental slope along the east coast of Canada and the United States. Mienis studied the area to the west of Ireland along the edges of the Rockall Trough. In her research Mienis analysed environmental factors like temperature, current speed and flow direction of seawater as these determine the growth of cold-water corals and the carbonate mounds. The measurements were made using bottom landers, observatories placed on the seabed from the NIOZ oceanographic research vessel ‘Pelagia’ and brought back to the surface a year later.
Cold-water corals are mainly found on the tops of carbonate mounds in areas where the current is high due to strong internal waves. These waves are caused by tidal currents and lead to an increase in local turbulence that results in the seawater being strongly mixed in a vertical direction. The outcome is the creation of a kind of highway between the nutrient-rich, sunlit zone at the sea surface and the deep, dark strata where the 380 metre-high tops of the mounds are found. This allows the cold-water corals to feed on algae and zooplankton that live in the upper layers of the sea. Lophelia pertusa and Madrepora oculata are the most important coral species found on the European continental slopes.
How the carbonate mounds were formed was investigated by using a piston core from the research vessel to take samples of up 4.5 metres of sediment. These cores were then cut into thin slices that were analysed separately; the deeper the layer, the older the sediment. The samples studied were aged up to 200,000 years old. Large hiatuses found in the core were possibly caused by major changes in tidal currents. The groups of carbonate mounds develop in the direction of the strongest current and their tops are of equal height. The mounds were found to be built up from carbonate debris and sediment particles caught in between coral branches. These cold-water coral reefs have, therefore, not developed as a result of leakage of natural gas from the sea bed. However, that may well be the case in the Gulf of Mexico. This area is currently being studied from the American research vessel ‘Nancy Foster’ by Furu Mienis, her supervisor Tjeerd van Weering and NIOZ associate researcher Gerard Duineveld.
Climate change has exerted a considerable influence on the growth of corals and the development of carbonate mounds. For example, corals stopped growing during ice ages. Present-day global warming and the resulting acidification of the oceans also pose a threat: organisms are less effective at taking up carbonate from seawater that is too acidic. This is true not only for corals but also for some species of algae that are a source of food for the corals. Other activities on the seabed that can cause damage to the coral reefs are offshore industries and bottom trawlers. A number of European areas containing cold-water coral reefs have thankfully already obtained protected status.
This research was funded by the Netherlands Organisation for Scientific Research (NWO) and the European Science Foundation (ESF).

http://www.underwatertimes.com/news.php?article_id=89106275310