Confirmed: Microbial life found half mile below Antarctic ice sheet

August 22, 2014 by  
Filed under Secrets of the Ocean

In an icy lake half a mile beneath the Antarctic ice sheet, scientists have discovered a diverse ecosystem of single-celled organisms that have managed to survive without ever seeing the light of the sun.

The discovery, reported Wednesday in the journal Nature is not so much a surprise as a triumph of science and engineering. The research team spent 10 years and more than $10 million to prove beyond a shadow of a doubt that life did indeed exist in subglacial lakes near the South Pole.

“It’s the real deal,” said Peter Doran, an Earth scientist at the University of Illinois at Chicago, who was not involved in the study. “There was news that they found life early this year, but a bunch of us were waiting for the peer reviewed paper to come out before we jumped for joy.”

John Priscu, the lead scientist on the project, has been studying the Antarctic for 30 years. He published his first paper describing how life might exist in the extreme environment beneath the ice sheet in 1999, and has been looking for definitive proof ever since.

In the winter of 2013-2014, he finally got his chance. After spending millions on a drill that could bore a clean hole free of contaminants through the ice sheet, and moving more than 1 million pounds of gear on giant sleds across the Antarctic ice sheet, he and his team had just four frenzied days to collect the water samples that would prove whether his theories were right or wrong.

Before claiming victory, he wanted to see three lines of evidence that life did exist in the underwater lake. He wanted to visually see the cells under a microscope, he wanted to prove they were alive by feeding them organic matter and measuring their respiration rate, and he wanted to see how much ATT was in their cells.

“I wasn’t surprised to find life under there, but I was surprised how much life there was, and how they made a living,” said Priscu, who teaches at Montana State University. “They are essentially eating the Earth.”

Priscu and his team report the discovery of close to 4,000 species of microbes growing in the cold, dark environment of Subglacial Lake Whillans in western Antarctica. Each quarter teaspoon  of the tea-colored lake water that they brought to the surface had about 130,000 cells in it, they write.

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The WISSARD camp sitting .5 a mile above the subglacial Lake Whillans in Antarctica. (J. Priscu / MSU)

“I think we were all surprised by that number,” said Brent Christener of Louisiana State University and the lead author of the Nature paper. “We’ve got lakes here on campus that we can take samples of and the numbers are about in that range.”

Life in the lakes of Louisiana has sunlight to provide it with energy, but in the lightless environment of Subglacial Lake Whillans, the microbes rely on minerals from the bedrock and sediments instead. The pressure of the slowly moving ice above the lake grinds the underlying rock into a powder, liberating the minerals in the rock into the water, and making them accessible to the microorganisms living there, explains Christener. The microbes act on those iron, ammonium and sulphide compounds to create energy.

“Ice, water and rock is all that is really needed to fuel the system,” he said.

The findings have major implications for the search for life outside of Earth, especially on the moons of Enceladus and Europa, where scientists believe a thick icy crust covers a vast, internal liquid ocean.

“Europa has an icy shelf and liquid water beneath it, just like we find in the Antarctic system which allows us to draw some conclusions about what we might find there,” said Priscu. “I’d love to be around when we finally penetrate that environment to look for life.”

Lake Whillans, the first lake to be sampled in Antarctica, is a shallow lake, about 6 feet deep, and about 37-square-miles in size. Priscu compares it to the lakes you might see in the Mississippi Basin, with rivers running through it and bringing some of the lake water out into the Indian Ocean.

To sample it, the researchers developed a new type of hot water drill system.

“In principal it is nothing more than a kilometer (about 1/2 a mile) garden hose that you shoot hot water through,” said Christener, “but in reality it is a complex monster.”

The tricky part was using the hot water to drill down into the ice without getting any of that water in the lake. “It’s like taking an 800 page novel and drilling down into 799 pages and then stopping,” he said.

The researchers brought about 13 gallons of the lake water back to the surface to study its chemistry and to see what might be living in it. The water was a brownish color because of the very fine particles that were suspended in it. The particles were so fine, that even after a few days, they did not settle to the bottom of the containers.

Going forward, the researchers want to learn more about how nutrients created by microbial activity in Lake Whillans affects the water in the Indian Ocean. They also think there may be large amounts of the greenhouse gas methane being produced in the lake that could be released into the atmosphere if the Antarctic ice sheet melts.

They would also like to look at other types of subglacial lakes on the continent, some of which are 3,000 feet deep and buried beneath 2 miles of ice.

“Now that we have shown that life can exist in this environment, we’d like to look at other lake types to see the biodiversity and ecosystems that exist under the ice, and get a better idea of their global importance,” said Priscu, who was on his way to plan the next expedition.

The team is going back to Antarctica with their drill in November.

“Hopefully we’ll have more discoveries coming soon,” he said.

For more news on amazing science, follow me @DeborahNetburn and “like” Los Angeles Times Science Health on Facebook.


Copyright © 2014, Los Angeles Times

Article source: http://www.latimes.com/science/sciencenow/la-sci-sn-microbe-ecosystem-antartic-ice-sheet-20140819-story.html

Even in Deepwater Canyons, America’s Corals At Risk

August 18, 2014 by  
Filed under Secrets of the Ocean

At the beach this summer, gazing out over the waves from the shoreline, it’s hard to imagine the underwater world that lies just below the blue expanse: Partly because it’s so other-worldy, and partly because we just don’t know very much about it.

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A squat lobster makes its home among various deep-sea corals in Norfolk Canyon, offshore Virginia. (Image courtesy of Deepwater Canyons 2013 - Pathways to the Abyss, NOAA-OER/BOEM/USGS.)

Scientific exploration into the ocean’s depths reveals new discoveries every day, and researchers at the U.S. National Oceanic and Atmospheric Administration (NOAA) are at the forefront on this work. Take a look at the incredible images from some of their recent dives off the Atlantic Coast:

These amazing gardens of deep-sea coral communities, in Dr. Seuss-like shapes and colors, are a sanctuary for marine life. They serve as a nursery for young fish and crustaceans, and shelter a range of sea life seeking a safe haven from threats that lie in the open waters of the deep sea.

However, the Atlantic’s deep-sea coral communities are at risk. They are highly vulnerable to harm from fishing gear, such as trawlers that pull their fishing nets along the bottom of the ocean. Most deep-sea corals are very slow-growing, so once they’re cut down, that habitat remains destroyed for a very long time. In fact, one pass of trawl gear can destroy corals that have been growing for hundreds, even thousands, of years.

The public now has an opportunity to help protect these ocean oases. Last Monday, the Mid-Atlantic Fishery Management Council, made up of federal officials and state representatives from New York, New Jersey, Delaware, Pennsylvania, Maryland, Virginia and North Carolina, took an historic step forward to adopt protections for the region’s unique, ecologically important and highly vulnerable deep-sea coral communities. The Council released a full array of options for deep-sea coral protections and will soon ask the public to weigh in on the best ways to preserve these ecosystems.

This is the moment to act on the issue. Because of their depth and rugged topography, the deep-sea coral communities off the Atlantic coast have been largely sheltered from harmful bottom trawling. But as traditional fish species become overfished or markets change, fishing will continue to move into deeper waters and more difficult terrain.

We have a unique window to protect the deep-sea corals and the ecosystems they help support before irreversible damage is done. The Council should protect against the use of damaging fishing gear in both discrete coral protection zones, which would safeguard particularly high-value coral habitat like submarine canyons, and broad coral protection zones, which would provide a level of protection for deeper areas in the region until it is determined that coral communities are not present in these areas.

NRDC is working to ensure that these incredible resources are protected for the future. Public hearings to discuss the Council’s proposed protections will be held this fall — it is important that every voice is heard.

A version of this article was originally published on Live Science Expert Voices.

Article source: http://switchboard.nrdc.org/blogs/achase/even_in_deepwater_canyons_amer.html

Who Owns the Ocean Floor?

August 14, 2014 by  
Filed under Secrets of the Ocean

Deep-sea mining is coming. Some of the biggest mineral deposits are around the Cook Islands (above). (Brian Scantlebury/Flickr)

That cell phone you carry. It’s made from copper, gold, lead, nickel, zinc and a plethora of less known, hard-to-pronounce metals, not to mention the mined materials needed for the battery that powers the device. Same goes for your computer and other electronics you use on a daily basis.

The desire for these products is unflagging, with newer versions requiring an ever more complicated cocktail of minerals. Yet our resources on land aren’t limitless, so we’ve turned to the sea in search of new supply. “The world’s demand for minerals continues to increase and the terrestrial resources are becoming stretched,” writes the International Seabed Authority (ISA), which controls all mineral-related activities in international waters. “In addition, deep seabed resources often contain a higher concentration of valuable minerals than their terrestrial alternatives.”

The ocean floor teems with metal (at least in spots we’ve targeted so far): copper and nickel, cobalt and silver, even gold. Many consider it the next frontier in mining. Yet much of the ocean remains unstudied, meaning we have no baseline for determining what harm such a disturbance might cause. As we near the first deep-sea mining expeditions — Australian-based Nautilus has the proper permits and could be working below the waves as soon as 2016 — scientists are scrambling to answer these questions before we no longer can.

Heavy Metals
Ocean waters cover more than 70 percent of our Earth’s surface. Yet we’ve explored a mere droplet, according to NOAA. “For all of our reliance on the ocean, 95 percent of this realm remains unexplored, unseen by human eyes,” notes NOAA’s National Ocean Service.

“The extent that we’ve covered is very, very small,” confirms marine biologist Christian Neumann. He’s part of the Deep Ocean Stewardship Initiative or DOSI, a multi-disciplinary group formed in 2013 aimed at making sure the right people are paying attention to the right issues surrounding deep-sea mining.

DOSI and other projects like MIDAS (stands for Managing Impacts of Deep-seA reSource exploitation) have much work to do, because of the staggering amount we still don’t know.

We do know, however, that great potential sits on, and below, the seabed floor. “There are certainly rich deposits to be had in our deep oceans and now it is possible to reach them,” Maria Baker, project manager of the International Network for Scientific Investigations of Deep-Sea Ecosystems (INDEEP) told weather.com by e-mail.

The three types of deep-sea mining are worth describing briefly. The first, seafloor massive sulfides (SMS), are caused by hydrothermal fluids on or below the seafloor along the oceanic plate boundaries. “That’s the type of deposit off Papua New Guinea,” Phil Weaver of MIDAS told weather.com, and that’s where Nautilus plans to mine. The largest known SMS deposit is a 94-million-ton expanse of dry ore containing gold, silver, copper and zinc in the Red Sea.

An example of a manganese nodule, one of the three main sources to find mineral deposits on the ocean floor. (GRID-Arendal)

Cobalt-rich crusts, another type of mining, are deposits full of cobalt and other metals found on the seafloor, typically on seamounts, and are typically irregularly contoured. Despite the abundance of these crusts — one ISA estimate says they cover nearly 2 percent of the entire ocean floor — Weaver predicts this mining is the furthest off.

Which leaves manganese nodules, metal-containing rocks found thousands of feet below the surface that can be mined by sifting just the top foot or so of seabed. The Pacific holds an abundance of these, particularly in a spot called the Clarion-Clipperton Fracture Zone and around the Cook Islands. “The nodules in the Cook Islands lie in national waters. The rest is in international waters and requires permission from the International Seabed Authority,” Weaver said. “The ISA has only, so far, given license for exploration, not for exploitation. It’s still working on the regulations that will be put in place to govern and manage exploitation. Those won’t be in place for two or three years yet.”

Exploitation vs. Protection
So while mining of our ocean deep isn’t happening this month or next, it will happen in the near future. “It’s coming,” Neumann said. “But it’s not tomorrow, and it’s not the day after tomorrow.” That gives us time to ask — and hopefully answer — some important questions. Like: who owns the ocean floor, and how do we both explore deep-sea resources and care for the ecosystems that house them?

The UN Convention on the Law of the Sea states that the deep-sea minerals found within a nation’s marine boundaries — 200 miles beyond their physical borders — belong to that nation. That border can expand up to 350 nautical miles, Weaver said, if the nation applies for and is granted an extension, but beyond that, waters fall under ISA jurisdiction, with any discoveries therein deemed the “common heritage of mankind.”

Like it or not, that phrase, the common heritage of mankind, seems to put the onus on all of us to understand how we’ll affect these deep-sea ecosystems. Many scientists working in this realm think so. “These environments are just so complex,” Baker said. “It is very important that careful monitoring of any mining activity that does go ahead is extremely well thought through and standardized.”

“[The deep ocean] is often forgotten or understood as something that isn’t valuable from an ecological standpoint,” added Neumann. “But it is.”

MIDAS is in the midst of a three-year, $16 million project to determine whether these ecosystems will mind our presence. Most recently, a team explored a region of the Mid-Atlantic Ridge near the Azores to study plumes from mining and species that live near hydrothermal vents, Nature reported. “We don’t know how far the plumes will travel and how much toxic material it will contain,” Weaver said. “It will suffocate bottom-living organisms in the vicinity of the mining. We don’t know how far it’ll spread.”

Scientists also don’t know just how toxic the material will be, whether it matters where excess water gets dumped, how species in extremely stable environments might handle disturbances. The list goes on. The idea isn’t to halt deep-sea mining, but rather to establish a baseline for what these ecosystems currently look like and a set of best practices, Baker said. “The depth of studies required to fully understand these systems and to gauge the potential impact on the environment would require significant funding and time for survey and analysis.”

There’s still time, but we need to act now, she added. “We are certainly running out of time.” As the mining industry moves forward, the environmental stewards can’t afford to stand still.

Editor’s Note: An earlier version of this article listed Nautilus as Toronto-based.


Article source: http://www.weather.com/news/science/who-owns-ocean-floor-20140819

SATANIC ‘HELL DIAMOND’ tells of sunless subterranean sea

March 13, 2014 by  
Filed under Secrets of the Ocean

For years scientists have theorised about the amount of water locked in the Earth’s infernally hot depths, frustrated at not being able to get at a sample. Now geologists claim to be closer to an answer – thanks to a single ugly diamond found in Brazil.

The $20 diamond that yielded the ringwoodite sample

The brownish gem – bought for about $20 but of inestimable scientific value – has given researchers the first ever terrestrial sample of a rare mineral known as ringwoodite – the highest pressure high-pressure polymorph of olivine currently known to exist.

Analysis of the tiny sample of ringwoodite within the glistening gem shows that it contains a significant amount of water – 1.5 per cent of its weight – hinting at huge volumes of water beneath the surface of the Earth.


“This sample really provides extremely strong confirmation that there are local wet spots deep in the Earth,” said Graham Pearson of the University of Alberta. “That particular zone in the Earth, the transition zone, might have as much water as all the world’s oceans put together.”

Olivine – a green magnesium iron silicate – has been predicted to exist in its high-pressure gemstone form, peridot in the transition zone. Ringwoodite, the highest pressure peridot, has previously been found in meteorites, but has never been discovered on Earth before because scientists can’t reach the planet’s core.

The Brazilian “diamond” was found on the surface in 2008 after being brought to the top by a volcanic rock known as kimberlite. When Pearson and his team bought the sample, they were actually looking for another mineral and stumbled on the ringwoodite by accident.

“It’s so small, this inclusion, it’s extremely difficult to find, never mind work on,” he said, “so it was a bit of a piece of luck, this discovery, as are many scientific discoveries.”

The tiny sample of mineral has confirmed around 50 years of theoretical work by geophysicists and seismologists trying to define the makeup of the interior of the Earth and in a way, proves both the dry and wet theories.

It shows that the transition zone is an oasis of water in what is otherwise a very dry deep core, containing a vast mass of water recycled from the surface. This water may be responsible for many of the tectonic and volcanic features that make the Earth such a unique planet.

“One of the reasons the Earth is such a dynamic planet is because of the presence of some water in its interior,” Pearson said. “Water changes everything about the way a planet works.”

The full study, “Hydrous mantle transition zone indicated by ringwoodite included within diamond”, was published in Nature. ®

Gemnote

The University of Minnesota has a reasonably informative page about olivine here.

Article source: http://www.theregister.co.uk/2014/03/13/mineral_water_earth_core/

Cool, interactive site shows you how ocean currents carry flotsam around the globe

September 3, 2013 by  
Filed under Secrets of the Ocean


Drop a message-in-a-bottle into the Gulf of Mexico, somewhere near New Orleans, and, 10 years later, your missive has a high likelihood of ending up near Cuba — or northern France. The website Adrift uses data from a global system of floating buoys to show you how ocean currents carry things like plastic debris around the planet.

Adrift Screenshot

Article source: http://boingboing.net/2013/09/03/cool-interactive-site-shows-y.html

Famed Roman shipwreck reveals more secrets

January 3, 2013 by  
Filed under Secrets of the Ocean

Ancient artifacts resembling the Antikythera mechanism, an ancient bronze clockwork astronomical calculator, may rest amid the larger-than-expected Roman shipwreck that yielded the device in 1901.

Marine archaeologists report they have uncovered new secrets of an ancient Roman shipwreck famed for yielding an amazingly sophisticated astronomical calculator. An international survey team says the ship is twice as long as originally thought and contains many more calcified objects amid the ship’s lost cargo that hint at new discoveries.

At the Archaeological Institute of America meeting Friday in Seattle, marine archaeologist Brendan Foley of the Woods Hole (Mass.) Oceanographic Institution, will report on the first survey of Greece’s famed Antikythera island shipwreck since 1976. The ancient Roman shipwreck was lost off the Greek coast around 67 BC,filled with statues and the famed astronomical clock.

“The ship was huge for ancient times,” Foley says. “Divers a century ago just couldn’t conduct this kind of survey but we were surprised when we realized how big it was.”

Completed in October by a small team of divers, the survey traversed the island and the wreck site, perched on a steep undersea slope some 150 to 230 feet deep in the Mediterranean Sea.

The October survey shows the ship was more than 160 feet long, twice as long as expected. Salvaged by the Greek navy and skin divers in 1901, its stern perched too deep for its original skin-diver discoverers to find.

The wreck is best known for yielding a bronze astronomical calculator, the “Antikythera Mechanism” widely seen as the most complex device known from antiquity, along with dozens of marble and bronze statues. The mechanism apparently used 37 gear wheels, a technology reinvented a millennium later, to create a lunar calendar and predict the motion of the planets, which was important knowledge for casting horoscopes and planning festivals in the superstitious ancient world.

A lead anchor recovered in a stowed position in the new survey shows that the ship likely sank unexpectedly when “a storm blew it against an underwater cliff,” says marine archaeologist Theotokis Theodoulou of Greece’s Ephorate (Department) of Underwater Antiquities. “It seems to have settled facing backwards with its stern (rear) at the deepest point,” he says.

Antikythera Mechanism

The bronze Antikythera Mechanism used 37 gear wheels, a technology reinvented a millennium later, to create a lunar calendar and predict the motion of the planets.(Photo: Antikythera Mechanism Research Project)

Scholars have long debated whether the ship held the plunder of a Roman general returning loot from Greece in the era when the Roman Republic was seizing the reins of the Mediterranean world, or merely luxury goods meant for the newly built villas of the Roman elite. The last survey of the shipwreck was led by undersea explorer Jacques Cousteau, whose documentary Diving for Roman Plunder chronicled that 1976 effort, which appears to have excavated the ship’s kitchen.

The October survey team watched the 1970s documentary to help orient themselves to the wreck site. “They didn’t have the diving technology that we now have to do a very efficient survey,” Theodoulou says.

Along with vase-like amphora vessels, pottery shards and roof tiles, Foley says, the wreck also appears to have “dozens” of calcified objects resembling compacted boulders made out of hardened sand resting atop the amphorae on the sea bottom. Those boulders resemble the Antikythera mechanism before its recovery and restoration. In 2006, an X-ray tomography team reported that the mechanism contained at least 30 hand-cut bronze gears re-creating astronomical cycles useful in horoscopes and timing of the Olympic Games in the ancient world, the most elaborate mechanical device known from antiquity until the Middle Ages. “The (objects) may just be collections of bronze nails, but we won’t know until someone takes a look at them,” Foley says.

The survey effort, headed by Aggeliki Simossi of the Ephorate of Underwater Antiquities,will continue for the next two years. The international survey team will look in two different locales for ancient shipwrecks in that time, while Greek antiquities officials ponder further exploration. An amphora recovered from the wreck will also have its inner walls tested for DNA traces of the regular cargo, such as wine, once carried by the vessel.

Recovery of whatever cargo remains with the wreck, now covered in sand, presents a technically difficult, but not impossible, challenge for marine archaeologists.

“Obviously there are a lot of artifacts still down there, but we will need to be very careful about our next steps. This ship was not a normal one,” Theodoulou says.

Article source: http://www.usatoday.com/story/tech/2013/01/03/antikythera-shipwreck-survey/1804353/

Into the Blue Serengeti

November 24, 2012 by  
Filed under Secrets of the Ocean

Blue whales are among the Pacific predators whose large-scale movements have been tracked. They dine on small crustaceans called krill, and, like some “nomadic” African lions, migrate to where their prey is seasonally abundant.

The dugout canoe does not know the depth of the water” (Umubindi ushira uvimye). So say the Hangaza, a group of more than 150,000 people who live along Lake Victoria, west of Tanzania’s Serengeti National Park. The proverb rings true: floating on the water won’t tell you what is going on below. Half a world away from Tanzania, along the United States West Coast, oceanographers are finding new ways of looking beneath research vessels that ply the Pacific. They’re getting a fish’s eye view of the deep by placing electronic tags on predators such as blue whales and California sea lions, yellowfin tuna and white sharks. As the data come in, their thoughts turn to the Serengeti.

Their project is called Tagging of Pacific Ocean Predators (TOPP). It focuses on certain areas of the Pacific, among them the California Current, an undersea river of water that flows south along the western coast of North America, beginning off British Columbia and ending near Baja California. The current supports large populations of whales and seabirds, and fuels important fisheries. Its productivity comes from an upwelling of cold subsurface waters, caused by prevailing northeasterly winds. The chilly waters ferry a steady supply of nutrients to the surface. The scientists are also studying an area called the North Pacific Transition Zone, the boundary between cold subarctic water and warm subtropical water, about halfway between Hawaii and Alaska. It’s a major trans-Pacific corridor for the movements of predators and prey.

Combined map shows movement patterns of twenty-two species documented by scientists collaborating in the TOPP (Tagging of Pacific Ocean Predators) project.

“These are the oceanic areas where food is most abundant,” says marine scientist Barbara A. Block of Stanford University’s Hopkins Marine Station in Pacific Grove, California. “They’re the savanna grasslands of the sea.” Knowing where and when species migrate is critical information for managing and protecting ecosystems, says biologist Daniel P. Costa of the University of California, Santa Cruz. TOPP was launched in 2000 by Block and Costa along with Steven J. Bograd of the National Oceanic and Atmospheric Administration’s Southwest Fisheries Science Center in La Jolla, Randall E. Kochevar of Stanford, and others. The project was part of the Census of Marine Life, a ten-year-long investigation of the diversity, distribution, and abundance of ocean species. TOPP became the world’s largest “biologging” (electronic tagging) study, involving more than seventy-five biologists, oceanographers, engineers, and computer scientists in eight countries. A decade of findings were reported in the journal Nature in June 2011. They reveal that the migrations of twenty-two marine species overlap.

“It’s been like looking across the entire African savanna,” says Block, “and trying to figure out: Where are the watering holes a zebra or a cheetah might frequent? Where are the fertile valleys? Where are the deserts that animals might avoid, and the migratory corridors species such as wildebeest use to travel from place to place?”

Block, Costa, and their colleagues use an array of technologies to track species and to record such environmental variables as water temperature, salinity, and depth. The TOPP project alone deployed 4,306 satellite-monitored tags, yielding a massive amount of data. Scientists spent two years synthesizing data sets. They discovered intersecting ocean hotspots and highways of life—and learned much about how marine conditions influence where animals hang out.

The results show that many migratory marine species, like animals on the Serengeti grasslands, return to the same regions each year, homing in with astonishing fidelity to the places where they were first tagged. “It’s akin to a student from London studying in far-off Rome and coming home each summer at the same moment—but doing it all in the dark without a map or compass, using only his or her internal sense of position and direction,” says Costa.

Leatherback sea turtle: Two populations have been observed, one whose females travel to lay eggs along beaches in the eastern Pacific, another that prefers western Pacific beaches.

Leatherback sea turtles, for example, travel huge distances between their nesting and feeding sites. In the Pacific Ocean, contingents from two populations of leatherbacks make their way each year to beaches along the eastern and western Pacific, respectively, to lay eggs. (An individual female will nest once every two or three years.) Helen Bailey of the University of Maryland Center for Environmental Science placed tracking devices on 135 leatherbacks’ shells. Leatherback turtles in the eastern Pacific were tagged at their nesting sites in Costa Rica and Mexico; western Pacific turtles were tagged at nesting sites in Indonesia and on their foraging grounds off the coast of California. The instruments transmitted satellite signals each time the turtles surfaced.

The results of Bailey’s study were published in the April 2012 issue of Ecological Applications. The western Pacific turtles traveled to feeding sites in the South China Sea, Indonesian seas, southeastern Australia, and the U.S. West Coast. “This wide dispersal,” says Bailey, “allows for a greater likelihood of finding food. It also means that the turtles are more vulnerable to being snagged unintentionally in fishing gear.”

The eastern Pacific leatherbacks have a different migration pattern, traveling south from nesting sites in Mexico and Costa Rica to the southeast Pacific. The turtles feed in offshore upwelling areas where their meals, almost exclusively jellyfish, are easy catches. “The limited feeding grounds of the east Pacific turtles make them vulnerable to changes that might occur in the abundance of jellyfish,” says Bailey. “Being caught in fishing gear also poses a greater risk to this population because it has a smaller range than western Pacific leatherbacks.” Entanglement in fishing gear is believed to be a major cause of death in leatherback sea turtles. James R. Spotila of Drexel University, a coauthor of the paper, notes that leatherback turtles are long-lived animals that take a long time to reach maturity. Because the species’ numbers are declining very fast, he considers it critical to take measures so they don’t go extinct. In the past thirty years, leatherback numbers in the eastern Pacific have dropped by 90 percent. Information on the turtles’ movements will help scientists determine where fishing should be limited at certain times of the year, says Bailey. A good precedent is a decision made in 2010 to close a swordfish and thresher shark fishery off California from mid-August to mid-November. That may have dramatically reduced incidental leatherback catches.

Water temperature is key to the seasonal migrations of many North Pacific Ocean species. That’s especially true in the marine ecosystem defined by the California Current, where whales, sharks, tuna, seals, seabirds, and turtles migrate each year. Like the African savanna, says Costa, the Pacific Ocean has a “Big Five”: he compares great white sharks to lions, bluefin tuna to leopards, blue whales to African elephants, leatherback sea turtles to black rhinos, and elephant seals to Cape buffaloes.

Scientists see parallels between migration patterns of prey, predators, and scavengers in East Africa’s Serengeti region and movements of species in the Pacific. Mapped here are (top left and right) zebra and wildebeest, (middle left and right) nomadic lion and hyena, and (bottom) vultures. Most lion prides occupy defended territories; nomadic lions, usually single males, tend to follow migrating herds while trying to avoid detection by resident males.

“The Serengeti is an ecosystem that’s synonymous with animal movements,” says ecologist Grant Hopcraft of the Frankfurt Zoological Society–Africa, headquartered in the Serengeti. “Each year more than one and a half million ungulates cross its plains.” Their seasonal migrations follow cyclic rains that lead to the growth of savanna grasses. Where grasses sprout up, ungulates such as wildebeest follow. Predators such as nomadic lions trail closely behind. (Although most lion prides occupy defended territories, nomadic lions, usually single males, tend to follow migrating herds while trying to avoid detection by resident males.) “The movements of marine species in the California Current are similar to those in the Serengeti,” says Hopcraft, “which raises the question: Why? Research at the population level suggests that it’s a changing food supply that drives animal migrations. But recent animal collaring [tracking] projects in the Serengeti show a huge amount of variation in individual species’ responses.”

There’s a lot more going on, Hopcraft believes, beneath the surface. “For the Serengeti—and the California Current—does an animal’s internal condition determine how it responds? Is it remembering previous routes and responding to the same cues? How will environmental change affect these great migrations of the land and the sea?”

Some predators spend their lives in the California Current, but others migrate long distances across the Pacific Ocean to reach the current’s abundant prey, including krill, sardines, anchovies, and squid. “Why a young bluefin tuna less than two years old wakes up in the light of the Japan Sea and decides to swim to Baja is unknown,” Block says. “But once it arrives, tagging data indicate that it lives there for years, taking advantage of the rich ‘forage’ along the coast.” Many species—including black-footed albatrosses, sooty shearwaters, bluefin tuna, and salmon sharks—migrate more than 1,200 miles from the western, central, or southern Pacific Ocean to reach the California Current’s rich food resources.

Farther off shore is the mysterious White Shark Café, as it’s known, an open-ocean winter and spring habitat for otherwise coastal great whites. The area, halfway between Baja California and Hawaii, hadn’t been a suspected shark hangout. But when scientists mapped data from satellite tags placed on 179 great white sharks between 2000 and 2008, they discovered that the sharks frequently travel to and loiter there. While at the café, they dive to depths of 1,000 feet as often as once every ten minutes, according to Salvador J. Jorgensen of Stanford’s Hopkins Marine Station. He and colleagues published their results online in November 2009 in Proceedings of the Royal Society B.

Coming mostly from rookeries along the Pacific coast, the great whites take up to 100 days to arrive, traveling at about two knots. The study showed that the sharks adhere to a rigid route of migration across the sea, returning to exactly the same spot. Since both male and female sharks have been tracked to the café, an early hypothesis was that it could be the undersea equivalent of a trendy pickup bar. Further studies, however, revealed that juvenile sharks also make their way there.

The purpose of the deep dives is not yet known, with the great whites lingering, often for months, in what seems to be an oceanic “desert” where food is scarce. Michael L. Domeier of the Marine Conservation Science Institute in Fallbrook, California, hypothesizes that the predators are feeding not on fish but on giant squid. Sperm whales, which feed on giant squid, are sighted in that area. Tracking other species, such as tuna, may help explain how the shark café came to be. “We’re only beginning to understand what it means to have the equivalent of lions in the ocean wilderness off California,” says Block.

Tuna, sharks, and blue whales may be cued to seasonal changes in chlorophyll concentrations,” says Bograd. Chlorophyll indicates the presence of phytoplankton, the grasslands of the sea.

Marine scientists work with a lightly anesthetized male northern elephant seal. After using fast-acting epoxy to glue a telemetry tag to the hair on the animal’s head, they measure blubber thickness with an ultrasound device and collect blood samples.

Elephant seals, for example, are drawn to a particular oceanographic feature—a boundary zone between two large rotating currents, or gyres. Along this boundary, the cold nutrient-rich waters of the subpolar gyre in the north mix with the warmer waters of the subtropical gyre to the south, driving the growth of phytoplankton and supporting a veritable feast of marine life.

An oceanic surface feature linked with the boundary zone and caused by blooms of phytoplankton is visible on satellite images. It moves seasonally by as much as 600 miles, however. Some elephant seals don’t follow; they continue to target the deep boundary zone between the two gyres.

Using data from nearly 300 tagged animals, Costa showed that the elephant seals travel throughout the northeast Pacific Ocean on foraging trips in search of prey such as fish and squid. “For the first time, we can truly say that we know what elephant seals as a population are doing,” he says. The results were published in May 2012 in the journal PLoS ONE.

A small number of elephant seals search for food in coastal regions, pursuing bottom-dwelling prey along the continental shelf. Among these is a female that feeds near Vancouver Island. She holds the record for deepest recorded dive by an elephant seal: 5,765 feet, more than a mile down.

The scientists have also looked at the partitioning of habitats by closely related species. Certain species, for example, are attracted to particular water temperatures; these preferences correlate with physiological adaptations. “We can now predict when and where individual species are likely to be in a given ocean region, and begin to understand the factors that control where they go next,” says Costa. “It’s the basis of ecosystem-based management.”

Following on the heels of TOPP, the scientists have spawned a new effort to study the blue Serengeti. “Where are the hotspots needing immediate protection?” Block asks. “We’re conducting the ecosystem science that reveals who’s at watering holes like White Shark Café and, most importantly, why.”

The ocean sunfish, or common mola, is known to dine on jellyfish, but its diet may be far broader.

One new project, called WhaleWatch, is looking at how to reduce the number of whales entangled in fishing gear, by identifying the areas whales are most likely to visit. Satellite tags have been attached to gray whales and to three other whale species—blue, fin, and humpback—off the U.S. West Coast. WhaleWatch scientists such as Bailey are using satellite data and migration models of gray whales to identify high-risk areas for the whales, and to develop conservation policies for reducing ship strikes and entanglements.

Among whales, the gray is the West Coast species most often hit by ships and caught up in fishing gear. Gray whales are known for long migrations of more than 10,000 miles from their feeding grounds in the Bering Sea to breeding areas along the coast of Baja California, Mexico. WhaleWatch researchers are analyzing gray whale satellite tracks to determine where the hotspots are for these whales.

This June, no one needed satellite tracking to find whales in Monterey Bay, California. As many as 100 blue whales splashed around in plain sight there. Upwelling led to a bumper crop of krill, the whales’ favorite food, and attracted countless other marine species. “It’s been one of the best ‘lunch stops’ in the Pacific,” says Block. “We need to protect these areas, places where large pelagic predators—the cheetahs and lions of the sea—gather.”

There’s an Africa-like game park in the waters off the West Coast, she says. “It will take enormous vision to preserve this wild place. Without conservation of such ocean realms, the bluefin tunas and blue whales, whale sharks and great whites might not be there in future generations.”

Along the U.S. East Coast, humpback whales, also long-distance migrators, are frequently ensnared in fishing gear. This July, scientists at the Provincetown Center for Coastal Studies in Massachusetts freed a whale caught in fishing line wrapped around its mouth and head. The researchers are part of a team following satellite-tagged humpbacks in the Gulf of Maine.

The snagged whale is one often seen in local waters. A mark on its tail fluke is shaped like a giraffe, giving the humpback its name: Serengeti.

Article source: http://www.naturalhistorymag.com/features/242338/into-the-blue-serengeti

New carnivorous harp sponge discovered in deep sea

November 20, 2012 by  
Filed under Secrets of the Ocean

A blog by Scientific American.

You may remember the Monterey Bay Aquarium Research Institute (MBARI) from such discoveries as the Yeti crab, the squid with elbows and my personal favourite, the pigbutt worm, and now they’re back with footage of a new species of carnivorous sponge.

Seventeen years ago, Jean Vacelet and Nicole Boury-Esnault from the Centre of Oceanology at France’s Aix-Marseille University provided the first real evidence that a sponge could be more than, well, a sponge. They had discovered a new species of deep-sea sponge living in the unusual setting of a shallow Mediterranean sea cave, the inside of which mimicked the conditions of its usual habitat more than a kilometre below the surface. This allowed the researchers an unprecedented view of the sponge’s eating habits, and they watched as it snared its prey of small fish and crustaceans instead of absorbing bacteria and organic particles through their bodies, like most other sponge species do – including ones living in the very same cave.

Vacelet and Boury-Esnault’s sponges were of the Asbestopluma genus and belonged to the Cladorhizidae family of carnivorous demosponges – the class that contains over 90% of the world’s sponges. Since reporting their discovery in a 1995 issue of Nature, 24 new species of cladorhizid sponges, including the incredible ping-pong tree sponge (see below), have also been discovered. Yet due to the difficulty of studying their behaviour at such incredible depths, researchers have had little opportunity to describe essential aspects of their lives, particularly how they reproduce.

Chondrocladia, or ping-pong, sponge.  MBARI

Chondrocladia, or ping-pong, sponge. MBARI

Which is where MBARI’s remotely operated vehicles (ROVs) Tiburon and Doc Ricketts, come in. Using these deep-diving vessels, a team of researcher s led by Senior Research Technician Lonny Lundsten discovered a species of harp sponge called Chondrocladia lyra off the coast of California, at depths of 3316–3399m.

As Mr_Skeleton pointed out on Reddit this week, this sponge doesn’t look like it could clean anything. But it can catch prey, envelope it in membrane and digest it whole, so it certainly has other priorities. Based on footage of several individuals and two large, fragmentary specimens brought up by the ROVs, Lundsten’s team described how the vertical branches and horizontal stolons that make up the sponge’s basic harp-like structure, called a vane, are covered in barbed hooks and spines. They found that a number of crustacean prey were passively ensnared on these branches thanks to the Velcro-like hooks and then aggressively enclosed in a cavity to be dismembered into small, digestible particles, which provided direct evidence of the species’ carnivorous appetites.

The vertical branches of the harp sponge are tipped by swollen terminal balls containing packets of sperm.

The vertical branches of the harp sponge are tipped by swollen terminal balls containing packets of sperm.  MBARI

The vertical branches of the harp sponge are tipped by swollen terminal balls containing packets of sperm. MBARI

C. lyra can grow up to 37cm long – impressive for a sponge – and are anchored to the sea-floor by a structure called a rhizoid, which looks like a root system. They can have 1-6 vanes, each supporting a number of equidistant vertical branches, and each of these end in swollen terminal balls. According to the researchers, these terminal balls produce condensed packets of sperm called spermatophores, which are released into the surrounding water in the hopes of fertilising other harp sponges in the area. Each C lyra sponge also has an egg development area around the mid-point of the branches, and when the spermatophores make contact, these areas swell up as the eggs are fertilised and begin to mature.

The team suggests that the structure of the harp sponge is designed to ensure that they catch the most prey possible, and also maximise their chances of catching spermatophores from other harp sponges.

“Video footage taken as the ROVs approached specimens of C. lyra provided information about the biological diversity of the areas in which the sponges live,” the researchers added in their report in the current issue of Invertebrate Biology. “Among the coexisting invertebrates were unidentified sea anemones; the soft coral Anthomastus robustus, members of several species of sea pens; and the sea cucumber Paelopadites confundens, as well as another sea cucumber in the family Elipidiidae.”

Article source: http://www.nature.com/news/new-carnivorous-harp-sponge-discovered-in-deep-sea-1.11789

Creatures of deep new to scientists

November 20, 2012 by  
Filed under Secrets of the Ocean

Weird underwater discoveries such as an egg-eating Australian sea serpent and a strikingly coloured worm named after Star Wars‘ Yoda could carry on for decades to come, with new research estimating that up to one third of species remain undiscovered.

A study co-led by a University of Auckland expert and published today in international journal Current Biology calculated there were fewer than one million marine species on the planet, lower than some previous estimates. The number undiscovered likely amounts to a third of all species.

Hot spots for new finds included deep sea ecosystems and those in tropical areas, said Associate Professor Mark Costello from the University of Auckland, who co-led the research with Ward Appeltans of Flanders Marine Institute and the Intergovernmental Oceanographic Commission of Unesco.

“If we look at the number of undescribed species and samples from around the world, especially deep sea and tropical areas, the average over 100 studies was that about 30 per cent of those new species were new to science,” he told the Herald.

Easier identification, better technology and more scientists would boost the rate of discovery.

“It’s likely it will get harder and harder to find the rarer things, but it also gets more exciting.”

Bizarre species discovered within the past year included Yoda purpurata, which had features resembling the Jedi master’s large sagging ears, a crimson shrimp found at a depth of 2600m beneath the Norwegian Sea, and an odd-looking bristle worm discovered 1600m below the northeast Pacific.

“Knowing how many species there are in our oceans, and describing them, is vital for science and conservation for several reasons,” Professor Costello said.

“Species are the most practical measure for distinguishing habitats and tracking progress in exploring the earth’s biodiversity.

“They are as fundamental to biology as elements are to chemistry and particles to physics.

“So failure to consider all species in an ecosystem is analogous to an accountant ignoring items of inventory in a company’s stock.”

Better understanding of what species exist enabled more accurate estimates of extinction rates through habitat loss, while having a “master list” of species’ names was essential for quality assurance.

Research efforts have been boosted by the World Register of Marine Species – an open-access, online database that has received contributions from almost 300 scientists from 32 countries.

The study supports previous research by Professor Costello and colleagues, which used statistical modelling and an earlier version of the register to reach a similar estimate of the number of species on earth and in the oceans. It is also the culmination of 14 years’ work for Professor Costello, who began a European register of marine species in 1997 that expanded until the world register was initiated in 2006.

OCEANS STILL TO GIVE UP THEIR INHABITANTS

Around 226,000 species have been described by science and as many as 72,000 more are in collections awaiting description – yet hundreds of thousands more may still be waiting for discovery in our oceans.

The rate of discovery is, however, increasing, with an unprecedented 20,000 new marine species described in the past decade alone, suggesting that most marine species will be discovered this century.

Earlier estimates of ocean diversity had relied on expert polls based on extrapolations from past rates of species descriptions and other measures.

Those estimates varied widely, suffering because there was no global catalogue of marine species, and a new study gauging a more accurate figure canvassed 120 of the world’s top experts on the taxonomy, or classification, of marine species.

Mammals, birds, reptiles, insects and larger plants were some of the best-described groups of marine species to date.

Many of the species yet to be discovered will come from among the smaller crustaceans, molluscs, algae, worms, and sponges.

By Jamie Morton Jamienzherald Email Jamie

Article source: http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10847735

Deep sea expedition reveals Mediterranean secrets

August 30, 2012 by  
Filed under Featured, Secrets of the Ocean

During most of August, Ballard’s research team on board the EV Nautilus have concentrated on the unique geological makeup of the Eratosthenes Seamount, one of the largest features on the eastern Mediterranean seafloor.

Ballard shot to fame after ‘discovering’ the Titanic in 1985

“We have found a lot of fascinating things,” Ballard told DW, on board the Nautilus. “You have to realize that when you go where no one has gone before on planet earth, you are not really sure what you’re going to find.”

“We’ve been making some real biological discoveries, and we’ve also been mapping two Ottoman war galleys which sank about 3,000 feet beneath where we are right now.”

The remains of the Ottoman war galley were found along with a flintlock pistol and what appeared to be black rum bottles littering the sea floor.

Surprisingly, the metal pistol seemed to be remarkably well-preserved, but most of the wood from the ship has deteriorated having been eaten away by marine organisms.

Uncharted waters

Ballard found global fame in 1985 after discovering the Titanic some three miles below the surface of the Atlantic. This discovery gave the world its first glance at the ghostly ship that sank in April 1912 after hitting an iceberg.

His sensational discovery launched a whole new Titanic movement – spawning books, films and documentaries. It also gave Ballard the opportunity to be able to indulge in his passion of going “where no man has gone before.”

Ballard and his team have found a range of artefacts

His crew for the Cyprus expedition includes researchers, geologists and the renowned NASA astronaut, Cady Coleman, who is working as their navigator. She says that the earth’s oceans, much like deep space, remain a largely unexplored frontier.

“There are a lot of similarities in a general sense, but sometimes things happen really quickly – we suddenly see something underwater, we want to record its position immediately … And it’s up to me to coordinate those things and that’s kind of similar to being up in space.”

Rare discoveries

For those onshore, the expedition brought a once-in-a-lifetime adventure, as cameras beamed live, high definition pictures from the bottom of the Mediterranean sea to the internet.

Katy Croff Bell, chief scientist of the Nautilus Exploration Programme, says that many viewers to the web stream were able to delve into the oceans’ secrets. Viewers witnessed a huge shark crossing the ship’s path with other highlights – including live pictures of mating squid and fossilized whale bones.

“The most unexpected discovery,” says Bell “was the fossilized rib cage of a large mammal, possibly a whale. We immediately contacted marine mammal specialists who are following up on the discovery to determine what and how old it is. We have also observed mating squid possibly for the first time ever for this species, and increased the known depth range of a particular species of fish.”

Biological discoveries have been made as well – above we see what’s believed to be fossilized whale bones

Technology applied

Bell says one of the most important results of their exploration was the use of a so-called tele-presence, which means experts were on-call day-and-night to assist the team onboard when discoveries were made.

“In every case, we were able to contact specialists who provided their expertise on how to proceed with studying the amazing discoveries that we have made in Cypriot waters,” she says.

For Robert Ballard, the most fascinating aspect of the expedition was the in-depth probe of the Eratosthenes Seamount, which measures 120 km long and 80 km wide. Its peak lies at the depth of 690 meters and it rises 2000 meters above the surrounding seafloor.

“It’s large, and it’s situated between Cyprus and Egypt, so we’re in an area traversed by a lot of ancient mariners. And during our time here we’ve been able to document a whole range of artifacts that have fallen to the ocean floor.”

Article source: http://www.dw.de/dw/article/0,,16206778,00.html

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