Understanding how deep-sea floor rocks and sediments interact with surrounding fluids and gasses is difficult to access. But a device created by two University of Illinois at Chicago geoscientists will duplicate extreme sea floor conditions inside a small chamber and examine samples inside the chamber by X-rays under these harsh conditions.

"Instead of going down to the abyssal plain of the ocean floor, we're bringing it to the lab," said Stephen Guggenheim, professor of earth and environmental sciences at UIC.

Guggenheim and emeritus professor Gus Koster van Groos say their high-pressure environmental chamber can simulate deep-sea pressure to 1,000 atmospheres -- comparable to deeper parts of the ocean -- and at temperatures from zero to 200 degrees Celsius.

The two began earlier prototypes of their device about a decade ago, improving it by trying different technologies and using more durable metals for the pressure vessel. X-ray diffraction is used to determine the composition of the materials reacting in the chamber and to study the effect of the sea floor environment. An inline mixing pump keeps suspensions mixed and in equilibrium.

Guggenheim said it is the first device to successfully obtain X-ray data under such severe conditions.

A new National Science Foundation grant will let the UIC scientists modify and improve their device, adding injection and extraction valves to facilitate sample manipulation.

"We'll be able to duplicate very precisely what happens on the ocean floor," said Koster van Groos. "We'll see minerals interaction with sea water and with gasses we can add, such as carbon dioxide or methane. And we can run experiments over longer terms, even for several months, to see what happens."

Guggenheim and Koster van Groos said their device may be used to study whether long-term, deep underground sequestering of excess carbon dioxide can be done safely. Carbon sequestration is under consideration as a way to combat global warming.

Guggenheim said engineers he's talked with say the device may be used for a variety of applications, such as examining the interaction between various materials and caustic acids.

"What's both unique and interesting is that you can look at the reaction while it's going on, without stopping or opening the containment vessel," he said.

Guggenheim and Koster van Groos hope their device will help scientists better understand such things as deep-sea mineral formation, clay mineralogy, mineral-brine interactions and what is going on in hydrothermal systems called black- and white-smokers.

The UIC scientists are also considering the study of organic material such as bacteria that can be introduced into their device after the injection valves are designed.

"We'd like to see how it changes the speed of reactions," said Guggenheim. "But ultimately, adding molecules from which organisms can develop might help us better understand how life evolved on the early earth."

Text by The University of Illinois Photo by NOAA

A study of animals visible to the naked eye and living in and on the seabed -- the 'macrobenthos' -- of the Straits of Magellan and Drake Passage will help scientists understand the biodiversity, biogeography and ecology of the Magellanic region.

"The biodiversity data are from my very first oceanographic cruise with the Chilean Navy in the Magellanic region in 1997, as an early undergraduate," said Dr Sven Thatje of the University of Southampton's School of Ocean and Earth Science at the National Oceanography Centre, Southampton: "The beauty of this dataset is the comprehensive diversity analysis with probably more than 10 per cent of species new to science." The cruise was part of the Chilean 'Cimar Fiordo III' expedition.

The soft sediments at the seafloor were sampled at depths ranging between 35 and 571 metres using a 'box corer' lowered from the Chilean navy vessel RV Vidal Gormaz. Samples were taken within the Straits of Magellan, the seaway separating mainland South America and the islands of the Tierra Del Fuego archipelago, and the eastern part of the Beagle Channel which separates South America from Antarctica. Samples were also taken from adjacent channels and fjords, some of which had been visited for the first time ever during the cruise.

A total of 173 species or morphological variants of species were identified, including crustaceans, molluscs and echinoderms. But polychaete worms, the group that includes ragworms dug by anglers for bait on sandy beeches at low tide, dominated both in terms of abundance and biomass.

At some locations the abundance of invertebrates peaked at more than 10,000 individuals per square metre, even without counting rare species that were missed or fast moving species that eluded capture. However, abundance, biomass and species richness all decreased with depth, consistent with reports from other regions such as the high Antarctic Weddell and Lazarev Seas.

The animals living at the seafloor depend for food on organic matter that rains down from the overlying ocean. "Variation in this flux of organic matter from the pelagic to the benthic is probably the major factor structuring these communities," said Dr Thatje.

It has been argued for the polychaetes of the Pacific coast of South America that shallow areas act as sources of colonisation, helping to maintain species diversity in deeper regions in the face of local extinction. "Such colonisation-extinction dynamics may also explain the patterns of diversity that we see in the Magellanic region," said Dr Thatje.

The Magellanic region was covered by ice 21,000 years ago, and the sea level was much lower than it is today. The Straits of Magellan probably did not fully open until approximately 7,000 years ago, after the ice had receded. The species now present in Magellanic waters must therefore have recolonised the region from adjacent Atlantic and Pacific areas, and indeed some of the polychaetes found in the Magellanic region are known from the Antarctic shelf.

The larvae of polychaetes can live as plankton for many months before resettling and developing into adults. "The dispersal of Antarctic species through larval transport in easterly circumpolar currents may explain their occurrence in the Magellanic region," said Dr Thatje.

Text and Photo by National Oceanography Centre, Southampton (UK)

Internationally coordinated research and field-testing on 'geoengineering' the planet's atmosphere to limit risk of climate change should begin soon along with building international governance of the technology, say scientists from the University of Calgary and the United States.

Collaborative and government-supported studies on solar-radiation management, a form of geo-engineering, would reduce the risk of nations' unilateral experiments and help identify technologies with the least risk, says U of C scientist David Keith, in an article published in the Jan. 27 online edition of Nature. Co-authors of the opinion piece are Edward Parson at the University of Michigan and Granger Morgan at Carnegie Mellon University.

"Solar-radiation management may be the only human response that can fend off rapid and high-consequence climate change impacts. The risks of not doing research outweigh the risks of doing it," says Keith, director of the Institute for Sustainable Energy, Environment and Economy's energy and environmental systems group and a professor in the Schulich School of Engineering.

Solar-radiation management (SRM) would involve releasing megatonnes of light-scattering aerosol particles in the upper atmosphere to reduce Earth's absorption of solar energy, thereby cooling the planet. Another technique would be to release particles of sea salt to make low-altitude clouds reflect more solar energy back into space.

SRM should not take the place of making deep cuts in industrial greenhouse gas emissions and taking action to adapt to climate change, Keith and his American colleagues stress. However, they say: "We must develop the capability to do SRM in a manner that complements such cuts, while managing the associated environmental and political risks."

The scientists propose that governments establish an international research budget for SRM that grows from about $10 million to $1 billion a year between now and the end of 2020. They urge that research results be available to all and risk assessments be as transparent and international as possible to build sound norms of governance for SRM.

Long-established estimates show that SRM could offset this century's predicted global average temperature rise more than 100 times more cheaply than achieving the same cooling by cutting emissions, Keith notes. "But this low price tag raises the risks of single groups acting alone, and of facile cheerleading that promotes exclusive reliance on SRM."

SRM would also cool the planet quickly, whereas even a massive program of carbon dioxide emission cuts will take many decades to slow global warming because the CO2 already accumulated in the atmosphere will take many years to naturally break down. The 1991 eruption of Mount Pinatubo, for example, cooled the planet by about 0.5 degrees Celsius in less than a year by injecting sulphur into the stratosphere.

But a world cooled by managing sunlight will present risks, the scientists note. The planet would have less precipitation and less evaporation, and monsoon rains and winds might be weakened. Some areas would be more protected from temperature changes than others, creating local 'winners' and losers.'

"If the world relies solely on SRM to limit (global) warming, these problems will eventually pose risks as large as those from uncontrolled emissions," they warn.

Field tests of SRM are the only way to identify the best technologies and potential risks, Keith says. He and the American scientists propose carefully controlled testing that would involve releasing tonnes -- not megatonnes -- of aerosols in the stratosphere and low-altitude clouds.

"If SRM proves to be unworkable or poses unacceptable risks, the sooner we know the less moral hazard it poses; if it is effective, we gain a useful additional tool to limit climate damages.."

Responsible management of climate risks requires deep emission cuts and research and assessment of SRM technologies, the scientists say. "The two are not in opposition. We are currently doing neither; action is urgently needed on both."

Text by The University of Calgary Photo by USGS

Tsunamis send electric signals through the ocean that appear to be sensed by the vast network of communication cables on the seabed, according to a new study led by Manoj Nair of the University of Colorado and NOAA.

Nair and his colleagues used computer models to estimate the size of an electric field created by the force of the 2004 Indian Ocean tsunami as it traveled over major submarine cables. Salty seawater, a good conductor of electricity, generates an electric field as it moves through Earth’s geomagnetic field.

“We estimate that the 2004 tsunami induced voltages of about 500 millivolts (mV) in the cables. This is very small compared to a 9-volt battery, but still large enough to be distinguished from background noise on a magnetically quiet day,” Nair said.

“By monitoring voltages across this network of ocean cables, we may be able to enhance the current tsunami warning system.”

But Nair cautioned that much research is still needed to effectively isolate the tsunami signals from other sources, such as Earth’s upper atmosphere, or ionosphere, whose signals can reach 100 mV. One millivolt is equivalent to one-thousandth of a volt.

Tsunamis are created by a large displacement of water resulting from earthquakes, landslides, volcanic eruptions, and even meteors hitting the ocean. Vessels far out at sea may not notice the waves passing underneath at the speed of a jetliner, because the wave heights are very small in the deep ocean. This makes their detection and monitoring a challenge.

The current tsunami warning system relies on a global seismometer network to detect earthquakes that may indicate that a tsunami has formed. Deep-ocean pressure sensors and coastal tide gauges are the only tools available to detect and measure an actual tsunami. The electric current induced in submarine cables may provide an additional way to confirm and track a tsunami.

Since the 2004 tsunami, the international warning system has expanded to include 47 deep-ocean pressure sensors, most of them in the Pacific area. After an investment of more than $100 million and strong support of Congress, NOAA has made tsunami warnings and education a priority. Within the United States, real-time data from these deep ocean sensors are used to forecast the impact of the tsunami on U.S. shorelines.

Co-authors are Alexei Kuvshinov of the Swiss Federal Institute of Technology, Zürich, S. Neetu of the National Institute of Oceanography, India and T. Harinarayana of the National Geophysical Research Institute, Hyderabad, India. Nair is also associated with NOAA’s Cooperative Institute for Research in Environmental Science at the University of Colorado.

Text and Photo by NOAA

For 80 years it has been accepted that early life began in a 'primordial soup' of organic molecules before evolving out of the oceans millions of years later. Today the 'soup' theory has been over turned in a pioneering paper in BioEssays which claims it was the Earth's chemical energy, from hydrothermal vents on the ocean floor, which kick-started early life.

"Textbooks have it that life arose from organic soup and that the first cells grew by fermenting these organics to generate energy in the form of ATP. We provide a new perspective on why that old and familiar view won't work at all," said team leader Dr Nick lane from University College London. "We present the alternative that life arose from gases (H2, CO2, N2, and H2S) and that the energy for first life came from harnessing geochemical gradients created by mother Earth at a special kind of deep-sea hydrothermal vent -- one that is riddled with tiny interconnected compartments or pores."

The soup theory was proposed in 1929 when J.B.S Haldane published his influential essay on the origin of life in which he argued that UV radiation provided the energy to convert methane, ammonia and water into the first organic compounds in the oceans of the early earth. However critics of the soup theory point out that there is no sustained driving force to make anything react; and without an energy source, life as we know it can't exist.

"Despite bioenergetic and thermodynamic failings the 80-year-old concept of primordial soup remains central to mainstream thinking on the origin of life," said senior author, William Martin, an evolutionary biologist from the Insitute of Botany III in Düsseldorf. "But soup has no capacity for producing the energy vital for life."

In rejecting the soup theory the team turned to the Earth's chemistry to identify the energy source which could power the first primitive predecessors of living organisms: geochemical gradients across a honeycomb of microscopic natural caverns at hydrothermal vents. These catalytic cells generated lipids, proteins and nucleotides which may have given rise to the first true cells.

The team focused on ideas pioneered by geochemist Michael J. Russell, on alkaline deep sea vents, which produce chemical gradients very similar to those used by almost all living organisms today -- a gradient of protons over a membrane. Early organisms likely exploited these gradients through a process called chemiosmosis, in which the proton gradient is used to drive synthesis of the universal energy currency, ATP, or simpler equivalents. Later on cells evolved to generate their own proton gradient by way of electron transfer from a donor to an acceptor. The team argue that the first donor was hydrogen and the first acceptor was CO2.

"Modern living cells have inherited the same size of proton gradient, and, crucially, the same orientation -- positive outside and negative inside -- as the inorganic vesicles from which they arose" said co-author John Allen, a biochemist at Queen Mary, University of London.

"Thermodynamic constraints mean that chemiosmosis is strictly necessary for carbon and energy metabolism in all organisms that grow from simple chemical ingredients [autotrophy] today, and presumably the first free-living cells," said Lane. "Here we consider how the earliest cells might have harnessed a geochemically created force and then learned to make their own."

This was a vital transition, as chemiosmosis is the only mechanism by which organisms could escape from the vents. "The reason that all organisms are chemiosmotic today is simply that they inherited it from the very time and place that the first cells evolved -- and they could not have evolved without it," said Martin.

"Far from being too complex to have powered early life, it is nearly impossible to see how life could have begun without chemiosmosis," concluded Lane. "It is time to cast off the shackles of fermentation in some primordial soup as 'life without oxygen' -- an idea that dates back to a time before anybody in biology had any understanding of how ATP is made."

Text by University College London Photo by NOAA

Most humans are blissfully unaware that we owe our healthful existence to trillions of microbes that make their home in the nooks and crannies of the human body, primarily the gut.

During evolutionary history, humans and bacteria have forged a mutually beneficial coexistence that provides the microbes' room and board in exchange for an array of biochemical services that help support everything from the digestion of food to a robust immune system.

But the intimate details of the relationship -- how the cells of the host and the cells of the bacteria coexist and interact -- are murky. Now, however, with the help of a diminutive Pacific Ocean squid and the bioluminescent bacteria that colonize its light-emitting, predator-fooling organ, scientists may have found a key to how animal hosts and their microbial symbionts maintain a healthy, rhythmic coexistence.

In a study published the week of Jan. 18 in the Proceedings of the National Academy of Sciences, researchers led by Margaret McFall-Ngai and Edward Ruby, professors of medical microbiology and immunology at the University of Wisconsin-Madison, chart the genetic interplay of symbiosis, revealing a daily molecular choreography that may well be characteristic of higher animals, including humans. If true, the insight would have important practical implications for human and animal health, as similar events occur when our tissues are colonized by the germs that make us sick.

"Nobody has a good handle on how the balance between host and symbiont is achieved," notes McFall-Ngai.

The Wisconsin researchers have studied the symbiotic interplay between the tiny Hawaiian bobtail squid, a two-inch creature common to the warm waters of the Pacific, and a glowing bacterium, Vibrio fischeri, for more than 20 years. The microbe colonizes and powers the animal's light organ, which serves to confuse squid predators lurking in the ocean depths at night when the squid is most active.

The idea behind the new study, explains McFall-Ngai, was to document the daily genetic dialogue between the bacterial symbionts and host-squid cells. Using microarrays that reveal which genes of the partners in an interaction are turned on or off, the group led by McFall-Ngai and Ruby found a daily pattern of activity that seems to show how host and bacterium maintain a healthy and balanced relationship.

"We found it is an extremely dynamic interaction, a profound daily rhythm on the part of both partners," says McFall-Ngai.

Several years ago, the Wisconsin researchers discovered that each day at dawn the bobtail squid expels about 90 percent of the bacteria that colonize its light organ. It had also been noted that the intensity of the bacterium's bioluminescence waxed and waned, with the most light produced at night when the squid is most active and most vulnerable to predators.

The new PNAS study assessed at different times of day the genetic activity of the squid host cells that support the bacterial symbionts as well as the bacteria themselves.

"Just before dawn, the animal turns on the majority of the genes associated with the cytoskeleton," the internal scaffolding of cells, according to McFall-Ngai. A close look at the tissues using electron microscopy revealed that the structure of the tissue colonized by Vibrio fischeri was dramatically disrupted at that time, with portions of the host-squid membranes shed into the spaces that the bacteria colonize.

Similar cytoskeletal changes have previously been observed in human pathogenesis, for example, in the destruction of intestinal tissues by E. coli 0157, which occurs in contaminated hamburger.

In the case of the squid, just after dawn and following the daily expulsion of the symbionts, the animal shuts down the genes of the cytoskeleton. As the residual symbionts begin to repopulate the tissues, the squid's cells regain their highly organized daytime condition. In response to the released host membranes, the bacteria turn on all the genes and pathways associated with using those membranes as food. Once that nutrient supply is exhausted, the squid then provide the symbionts with complex sugars for sustenance.

The bacteria, says McFall-Ngai, seem to be cycling through different metabolic states in response to different food sources provided by the host. The details teased out of the squid and its bioluminescent bacterium, says McFall-Ngai, may be more generally applicable to animal-microbial associations: "It is quite likely that such daily rhythms on the maintenance of animal-bacterial symbioses are more universal than in just this little squid."

Text and Photo by University of Wisconsin-Madison

How did the lemurs, flying foxes and narrow-striped mongooses get to the large, isolated island of Madagascar sometime after 65 million years ago?

A pair of scientists say their research confirms the longstanding idea that the animals hitched rides on natural rafts blown out to sea.

Professors Matthew Huber of Purdue and Jason Ali of the University Hong Kong say that the prevailing flow of ocean currents between Africa and Madagascar millions of years ago would have made such a trip not only possible, but fast, too. The findings, based on a three-year computer simulation of ancient ocean currents, will be published in the journal Nature and were posted on Nature's website on Jan. 20.

The idea that animals rafted to the island is not new. Since at least 1915, scientists have used it as an alternative theory to the notion that the animals arrived on Madagascar via a land bridge that was later obliterated by shifting continents. Rafting would have involved animals being washed out to sea during storms, either on trees or large vegetation mats, and floating to the mini-continent, perhaps while in a state of seasonal torpor or hibernation.

Huber and Ali's work supports a 1940 paper by George Gaylord Simpson, one of the most influential paleontologists and evolution theorists of the 20th century. Simpson introduced the concept of a "sweepstakes" process to explain the chance of raft colonization events taking place through vast stretches of geological time. Once the migrants arrived on the world's fourth largest island, their descendants evolved into the distinctive, and sometimes bizarre forms seen today.

"What we've really done is prove the physical plausibility of Simpson's argument," Huber said.

Anthropologists and paleontologists have good reason to be interested in Madagascar's animals. The island is located in the Indian Ocean roughly 300 miles east of Africa over the Mozambique Channel and is otherwise isolated from significant land masses. Its isolation and varied terrain make it a living laboratory for scientists studying evolution and the impact of geography on the evolutionary process.

Madagascar has more unique species of animals than any location except Australia, which is 13 times larger. The island's population includes 70 kinds of lemurs found nowhere else and about 90 percent of the other mammals, amphibians and reptiles are unique to its 226,656 square miles.

The question has always been how the animals arrived there in the first place. Madagascar appears to have been an island for at least 120 million years, and its animal population began arriving much later, sometime after 65 million years ago.

The raft hypothesis, which scientists refer to as "dispersal," has always presented one big problem, however. Currents and prevailing winds between Madagascar and Africa flow south and southwest, away from, not toward, the island.

Yet, the land bridge hypothesis also is problematic in that there is no geologic evidence that such a bridge existed during the time in question. Also, there are no large mammals such as apes, giraffes, lions or elephants, indigenous to Madagascar. Only small species such as lemurs, the island's signature species; hedgehog-like tenrecs; rodents; mongoose-like carnivores; and similar animals populate the island.

The animals of Madagascar also appear to have arrived in occasional bursts of immigration by species rather than in a continuous, mixed migration. They likewise appear to have evolved from single ancestors, and their closest relatives are in Africa, scientists say. All of which suggests Simpson's theory was correct.

Ali, who has a research focus in plate tectonics -- the large-scale motions of the Earth's outer shell -- kept running across the land bridge hypothesis in the course of his work. The question intrigued him because the notion of a bridge between Madagascar and Africa appeared to break rules of plate tectonic theory. A background in oceanography also made him think ocean currents between Africa and Madagascar might have changed over time.

"Critically, Madagascar and Africa have together drifted more than 1,600 kilometers northwards and could thus have disrupted a major surface water current running across the tropical Indian Ocean, and hence modified flow around eastern Africa and Madagascar," says Ali, an earth sciences professor.

That led Ali to contact Huber, a paleoclimatologist who reconstructs and models the climate millions of years in the past. Huber, a Purdue earth and atmospheric sciences professor, has a particular interest and expertise in ocean currents, which have a significant impact on climate.

Huber models ancient conditions at a time when the planet was much warmer than it is today, and he specializes in lengthy, highly detailed simulations. He uses the modeling of a warmer Earth in the past -- warm enough for crocodiles to live in an ice-free Arctic -- to help understand conditions generated by today's global warming and to project what the warming trend may hold for the future.

When Ali contacted him about the Madagascar question, Huber had just finished running a three-year simulation on a supercomputer operated by Information Technology at Purdue (ITaP), Purdue's central information technology organization. The modeling produced 100 terabytes of output -- data with potential uses for a variety of purposes, including a study of ancient ocean currents around Madagascar.

The Purdue professor was able to show that 20 million to 60 million years ago, when scientists have determined ancestors of present-day animals likely arrived on Madagascar, currents flowed east, toward the island. Climate modeling showed that currents were strong enough -- like a liquid jet stream in peak periods -- to get the animals to the island without dying of thirst. The trip appears to have been well within the realm of possibility for small animals whose naturally low metabolic rates may have been even lower if they were in torpor or hibernating.

Huber's computer modeling also indicates that the area was a hotspot at the time, just as it is today, for powerful tropical cyclones capable of regularly washing trees and tree islands into the ocean.

"It seems likely that rafting was a distinct possibility," the study concludes. "All signs point to the Simpson sweepstakes model as being correct: Ocean currents could have transported rafts of animals to Madagascar from Africa during the Eocene."

The raft hypothesis has always been the most plausible, says Anne Yoder, director of the Duke University Lemur Center. She specializes in using molecular biogenetic techniques and geospatial analysis to examine the evolutionary history of Madagascar. But Ali and Huber's study now puts hard data behind it, says the Duke professor of biology, biological anthropology and anatomy.

"I was very excited to see this paper," says Yoder, whom Nature asked to review the study prior to publication. "Dispersal has been a hypothesis about a mechanism without any actual data. This takes it out of the realm of storytelling and makes it science."

Ali says the study also is relevant to the movement of animal species elsewhere on the planet, lending support for dispersal over a competing idea that animals arrived at their positions on the drifting land masses of the continents as the Earth took its current form.

Moreover, the Madagascar study provided a test case confirming scientists' ability to model ocean and atmosphere interactions in a past greenhouse climate, Huber said. The National Science Foundation recently funded Huber to further simulate ocean currents in the Eocene epoch, roughly 39 million to 56 million years ago, using the methodology he applied to Madagascar.

Text and Photo by Purdue University

To the casual observer in the Gulf of Mexico, the seemingly sluggish red grouper is more of a couch potato than a busy beaver. But a new study led by researchers at The Florida State University reveals the fish to be both architect and ecosystem engineer.

Most abundant along Florida's west coast but also found on watery ledges and in crevices and caverns from North Carolina to Brazil, the red grouper excavates and maintains complex, three-dimensional structures that provide critical habitats for the spiny lobster and many other commercially important species in the Gulf of Mexico. The researchers watched it work hard to remove sand from the sea floor, exposing hard rocks crucial to corals and sponges and the animals they shelter.

In fact, the red grouper's sandy architecture is a monument to the interconnectedness of species and the vital role such connections play in the structural and functional diversity of the ocean, suggests Felicia C. Coleman, director of Florida State University's Coastal and Marine Laboratory.

"Watching these fish dig holes was amazing enough," Coleman said, "but then we realized that the sites they created served to attract mates, beneficial species such as cleaner shrimp that pick parasites and food scraps off the resident fish, and a variety of prey species for the red grouper. So it is no surprise that the fish are remarkably sedentary. Why move if you are clever enough to make everything you need come to you?"

Coleman and Christopher C. Koenig -- her spouse and fellow faculty member in the Department of Biological Science -- describe their study in a paper ("Benthic Habitat Modification through Excavation by Red Grouper, Epinephelus morio, in the Northeastern Gulf of Mexico") published online Jan. 9 in The Open Fish Science Journal. Their co-authors are Kathryn M. Scanlon, of the U.S. Geological Survey, Woods Hole, Mass.; Scott Heppell and Selena Heppell, Department of Fisheries and Wildlife, Oregon State University; and Margaret W. Miller, of the National Marine Fisheries Service, Southeast Fisheries Science Center, Miami, Fla.

"Red grouper are the 'Frank Lloyd Wrights' of the sea floor," said University of California-Davis Professor Susan Williams, who collaborated with Coleman on an earlier, related study. "Its sea-floor associates include commercially valuable species such as vermilion snapper, black grouper and spiny lobsters. If the groupers are overfished, the suite of species that depends on them is likely to suffer."

Working along the West Florida Shelf, Coleman and colleagues observed the red grouper's excavating activities during both its juvenile stage in inshore waters and its adult stage at depths of 300 feet.

"We suspected that the groupers created the habitat," Coleman said. "We found through a series of experiments that they not only dug the holes but also maintained them by carrying mouthfuls of sediment from the center of the pit to the periphery and expelling them through their gills and mouths, then brushing off the rocks with their tail fins."

As juveniles, red grouper excavate the limestone bottom of Florida Bay and elsewhere, exposing "solution holes" formed thousands of years ago when sea level was lower and freshwater dissolved holes in the rock surface. When sea level rose to its present state, the solution holes filled with sediment. By removing the sediment from them, the fish restructure the flat bottom into a three- dimensional matrix, which is enhanced by the settlement and growth of corals and sponges. Spiny lobsters are among the many species that occupy those excavations, especially during the day when seeking refuge from roving predators.

Loss of this habitat -- through the loss of red grouper due to intensive fishing -- has obvious consequences to the lobster fishery of South Florida, Coleman said. She warns that habitat engineers, like foundation species, must be maintained in a healthy state, or the consequences to fishery production could be severe.

"You can't remove an animal that can dig a hole five meters across and several meters deep to reveal the rocky substrate and expect there to be no effect on reef communities," Koenig said. "The juveniles of a species closely associated with these pits, vermilion snapper, are extremely abundant around the offshore excavations. It is possible that the engineered habitat is significant as a nursery for this species, which other big fish rely on as food. One could anticipate a domino effect in lost diversity resulting from the loss of red grouper-engineered habitat."

Suggested changes in fisheries management intended to reduce bycatch of sea turtles in the long-line fishery by pushing the fleet further offshore would increase the fishing pressure on red grouper and other ecosystem engineers, such as tilefish, found at greater depths, contends Coleman.

"Imagine the impact not only on red grouper and tilefish but also on a suite of deep-water grouper for which we have very little information, other than the fact that some of them are critically endangered," she said.

Text and Photo by Florida State University

A major increase in maximum ocean wave heights off the Pacific Northwest in recent decades has forced scientists to re-evaluate how high a "100-year event" might be, and the new findings raise special concerns for flooding, coastal erosion and structural damage.

The new assessment concludes that the highest waves may be as much as 46 feet, up from estimates of only 33 feet that were made as recently as 1996, and a 40 percent increase. December and January are the months such waves are most likely to occur, although summer waves are also significantly higher.

In a study just published online in the journal Coastal Engineering, scientists from Oregon State University and the Oregon Department of Geology and Mineral Industries report that the cause of these dramatically higher waves is not completely certain, but "likely due to Earth's changing climate."

Using more sophisticated techniques that account for the "non-stationarity" in the wave height record, researchers say the 100-year wave height could actually exceed 55 feet, with impacts that would dwarf those expected from sea level rise in coming decades. Increased coastal erosion, flooding, damage to ocean or coastal structures and changing shorelines are all possible, scientists say.

"The rates of erosion and frequency of coastal flooding have increased over the last couple of decades and will almost certainly increase in the future," said Peter Ruggiero, an assistant professor in the OSU Department of Geosciences. "The Pacific Northwest has one of the strongest wave climates in the world, and the data clearly show that it's getting even bigger.

"Possible causes might be changes in storm tracks, higher winds, more intense winter storms, or other factors," Ruggiero said. "These probably are related to global warming, but could also be involved with periodic climate fluctuations such as the Pacific Decadal Oscillation, and our wave records are sufficiently short that we can't be certain yet. But what is clear is the waves are getting larger."

In the early 1990s, Ruggiero said, a fairly typical winter might have an offshore wave maximum of a little more than 25 feet. It was believed then -- based primarily on data from two offshore buoys -- that 10 meters, or 33 feet, would be about as large as waves would ever get, even in a massive "100-year" storm.

But then a major El Nino -- which tends to bring larger waves, higher water levels and increased erosion -- happened in 1997-98 and led to a string of "100-year" wave events of around and above 33 feet. Researchers went back to the drawing board, continued to study data and storm events, and now believe that the maximum waves the region may face could approach or even exceed 50 feet.

Increasing wave heights, they said, have had double or triple the impact in terms of erosion, flooding and damage as sea level rise over the last few decades. If wave heights continue to increase, they may continue to dominate over the acceleration in sea level that's anticipated over the next couple of decades. The prior concern about what sea level rise could do, in other words, is already a reality. If sea levels do increase significantly in future decades and centuries, that will only add to the damage already being done by higher waves.

Exactly what impacts this will have in terms of beach erosion and shifting shorelines is difficult to predict, scientists say, because currents and sand move in complex ways, creating both "winners and losers" in terms of beach stability. But some effects are already visible, Ruggiero said.

"Neskowin is already having problems with high water levels and coastal erosion," Ruggiero said. "Some commercial structures there occasionally lose the use of their lower levels.

"Going to the future, communities are going to have to plan for heavier wave impacts and erosion, and decide what amounts of risk they are willing to take, how coastal growth should be managed and what criteria to use for structures," he said.

Hampering the research effort is the fact that two of the major buoys used for these studies, which are some distance off the Pacific Northwest coast and measure waves in deep water, were only installed in the 1970s. Even at that they provide two of the longest high-quality wave height records in the world. OSU researchers are studying historical records through climate data, old newspaper records and other information to try to recreate what wave heights and storm events were like going further back in time.

The largest wave height increases, scientists say, have occurred off the Washington coast and northern Oregon, with less increase in southern Oregon and nothing of significance south of central California. The study also noted that similar increases in wave heights have occurred in the North Atlantic Ocean, as well as the seasonal total power generated by hurricanes.

These issues do not consider the potential drop in land level that is expected to occur in this region with a subduction zone earthquake at some point in the future. Ruggiero noted that he did some research in Sumatra following the huge 2004 earthquake there -- an area with geology very similar to that of the Pacific Northwest -- and some of the shoreline had dropped from 1.5 to five feet. If and when that occurs, the impacts on shorelines could be enormous.

Text and Photo by Oregon State University

A new study has shown that echolocation evolved separately, but through the same genetic changes, in both dolphins and bats.

Scientists at Queen Mary, University of London have shown that the remarkable ability is shared by these very different animals at a much deeper level than anyone previously realised – all the way down to the molecular level.

Writing in the journal Current Biology, they describe how dolphins and bats have both evolved the same specialised form of inner-ear hair cells that allow them to use sophisticated echolocation: detecting unseen obstacles or tracking down prey by making a high frequency noise and listening for the echo that bounces back.

"The natural world is full of examples of species that have evolved similar characteristics independently, such as the tusks of elephants and walruses," said Stephen Rossiter of Queen Mary's School of Biological and Chemical Sciences. "However, it is generally assumed that most of these so-called 'convergent traits' have arisen by different changes in the animal's DNA. Our study shows that this very complex ability - echolocation - has in fact evolved by identical genetic changes in bats and dolphins."

According to Rossiter, the discovery represents an "unprecedented" example of convergence between two very different animals, and suggests that further studies might unearth more genetic similarities between species than scientists would have suspected.

"We were surprised by the strength of the evidence for convergence between these two groups of mammals, and, related to this, by the sheer number of convergent changes in the DNA that we found," he said.

Rossiter and colleague James Cotton teamed up with Shuyi Zhang from East China Normal University to sequence the Prestin gene, which describes a key protein found in the inner-ear hair cells of all mammals. The researchers discovered that this gene shows the very same changes in bats and dolphins, the results also clearly show how genetic changes have built up over time.

The prestin protein is known to drive the vibration of the hair cells in response to sound. It is possible that the genetic changes observed in bats and dolphins allow more rapid vibrations and, therefore, the higher frequency hearing that is needed for echolocation. Rossiter added; "the fact that it is the very same genetic changes that occurred twice in nature suggests that there might be a limited number of evolutionary routes to high frequency hearing in mammals".

Text by Queen Mary, University of London Photo by NOAA