Microbes Thrive in Deepest Spot on Earth

ORIGINAL: Live Science

17 March 2013

The central part of the autonomous instrument that was deployed to measure the oxygen dynamics of the sea-bed in the Mariana Trench at a depth of 11 km. Data documented intensified microbial life in the bottom of the trench as compared to conditions at the surrounding abyssal plains at 6 km water depth.  CREDIT: Anni Glud 

The deepest oceanic trench on Earth is home to a surprisingly active community of bacteria, suggesting other trenches may be hotspots of microbial life, researchers say. 

Life in the deep ocean often relies on organic matter snowing down from above. As these particles waft down, their nutrients get degraded by microbes attached to them, so only 1 to 2 percent of the organic matter produced in surface waters is expected to make it to the average ocean depth of about 12,150 feet (3,700 meters). Just how much makes it to the very deepest parts is unknown. 

To learn more about life in the dirt at the ocean's depths, scientists used a submersible lander to analyze mud from the surface of Challenger Deep, the deepest spot of the Mariana Trench at the bottom of the central west Pacific Ocean. This 36,000-foot-deep (11,000 m) trench is the deepest known point on Earth's surface. 

Natural trap 

The researchers analyzed the levels of oxygen consumption within the sediments, which revealed how active the deep-sea microbes were. They discovered unexpectedly high rates of oxygen consumption from the Mariana seafloor, indicating a microbial community twice as active as that of a nearby 19,700-foot (6,000 m) site about 35 miles (60 kilometers) to the south. [Strangest Places Where Life Is Found on Earth] 

"In the most remote, inhospitable places, you can actually have higher activity than their surroundings," researcher Ronnie Glud, a biogeochemist at the Southern Danish University in Odense, Denmark, told OurAmazingPlanet. 

Sediments from Challenger Deep also had significantly higher levels of microbes and organic compounds than the nearby, more elevated site. The investigators suggest the Mariana Trench acts as a natural trap for sediments from up high. Similar effects are seen in other submarine canyons. 

"It acts as a trap just because it's a big hole. If you have a hole in a garden, it just fills up because things blowing over it tend to fall in, and the same is true with the seafloor," Glud said. The trench is also located in a subduction zone where one of the tectonic plates making up the surface of the Earth is diving under another, "and these areas are very unstable, and frequently see earthquakes that can trigger mudslides that transport material into the trench," he added. 

Microbes, microbes everywhere 

Another team of scientists recently discovered communities of microbes thriving in the oceanic crust. That research looked at rocks up to about 1,150 to 1,900 feet (350 to 580 m) below the seafloor under about 8,500 feet (2,600 m) of water off the coast of the northwestern United States. These microbes apparently live off energy from chemical reactions between water and rock instead of nutrients snowing from above. 

"You can find microbes everywhere — they're extremely adaptable to conditions, and survive wherever they are," Glud said. 

The researchers are now analyzing other trenches to see what bacterial activity is also relatively high there. They also want to learn more about the genetics of bacteria in the Mariana Trench and other trenches "to see how special these bacteria are compared to other bacteria," Glud said. 

The scientists detailed their findings online March 17 in the journal Nature Geoscience. 

Follow OurAmazingPlanet @OAPlanet, Facebook and Google+.

Deep Sea Vents: Science at the Extreme

ORIGINAL: Environment.nationalgeographic.com

´

Deep sea vents in the Atlantic Ocean’s Mid-Atlantic Ridge support tubeworms, eelpout fish, and crabs. The Mid-Atlantic Ridge is an underwater mountain chain that extends about 10,000 miles (16,000 kilometers) from the Arctic Ocean to the southern tip of Africa. Photograph by Emory Kristof

Republished from the pages of National Geographic magazine

With a mile and a half (two and a half kilometers) of Pacific Ocean sitting on their shoulders, ghost-pale crabs and fish forage among blood-red tube worms. Such communities flourish where super-heated water gushes from seafloor springs. Advances in the tools that scientists use to investigate deep-sea ecosystems are expanding knowledge of these creatures and their hostile environment.

Strange Life Clearly Seen

Water heated as high as 760°F (404°C) by magma from Earth's interior billows from a seafloor chimney. The surrounding ocean is just a few degrees above freezing. When the two fluids meet, iron sulfide precipitates, giving the "black smoker" its color. In these dark depths, chemosynthesis—based on thermal and chemical energy from the vents—is the primary mechanism sustaining life.

A living cloud flecks the water around a clump of limpet-encrusted tube worms and mustard-yellow mussels in the high-definition image at far right. With a magnifying lens on another camera the cloud resolves into a crowd of flea like crustaceans called amphipods. Amphipod swarms like this one—observed at 9° N on the East Pacific Rise—may be the densest concentrations of invertebrate life on Earth.

High-intensity lighting and high-resolution imaging technologies provide researchers with the equivalent of a microscope to examine life in the deep sea. These tools can reveal organisms that have always been part of vent communities but have been hidden until now.

Timothy Shank, a marine ecologist at Woods Hole Oceanographic Institution, calls the array of previously unknown species found at vents "mind-boggling." He has calculated that, on average, a new species has been described every week and a half since biologists first visited the Galápagos Rift vents in 1979. "More than 20 years later," he says, "we're still on the tip of the iceberg. We're trying to understand relationships among vent animals—and we're still discovering new species!"

Evaluating an Arctic Oasis

La pesca ilegal es una matanza invisible

ORIGINAL: El Colombiano

POR: MARÍA VICTORIA CORREA

 12 de agosto de 2012

Pese a las promesas para fortalecer la autoridad pesquera, la tragedia crece en el mar.

Amontonados como zapatos, así se veían en la foto. Pero no eran zapatos, eran tiburones muertos, muchos sin cabeza, sin aletas. Los imaginé tristes, segundos antes de que murieran. 

La escena raya con la maldad cuando se ve a un pescador que los acomoda, tal vez en un acto de buena fe para que todos se cuiden sus muertes y la sangre y sus vísceras no hagan tanto ruido si se les ve esparcidos por el pequeño bote de bandera ecuatoriana. Entonces, perdón, como no eran zapatos, la imagen duele. 

Le duele a Sandra Bessudo, actual directora de Cooperación Internacional y experta en temas de conservación, quien insistió en poner los ojos sobre ese “bosque de agua” que vive sin quejarse y que se muere por dentro.

No deja dormir al vicealmirante Hernando Wills, jefe de Operaciones Navales de la Armada Nacional, quien compromete a todos sus hombres para que en el millón de kilómetros cuadrados de territorio marítimo que vigilan, detecten un acento no colombiano, un pequeño bote extranjero, haciendo faena en aguas nacionales. 

Y le preocupa al Gobierno, que lentamente busca consolidar una oficina que atienda la pesca ilegal en Colombia a manos de extranjeros y a pesar de que existe, los expertos apuntan a que la Autoridad Nacional de Acuicultura y Pesca, Aunap, es muy novata para evitar esta tragedia. 

¿De qué tragedia hablamos?

Yamauri es una de las motonaves más grande de bandera extranjera que este año ha ingresado al país. 

Cuando la Armada Nacional la retuvo los primeros días de enero, cerca al Parque Natural Malpelo, la faena alcanzaba la tonelada de atún, dorado y tiburón y en el bote, cual carnicería de barrio, estaban regadas las aletas que les habían acabado de cortar.

Radioactive bluefin tuna from Japan found in U.S. waters

ORIGINAL: Raw Story

By David Ferguson

Monday, May 28, 2012 17:28 EDT 

For the first time, scientists have discovered that tuna contaminated by last year’s radiation leak from the crippled Fukushima nuclear plant have crossed the Pacific Ocean into U.S. waters, according to the Associated Press. Scientists have been started to discover the radioactive fish some 6,000 miles from their place of origin, the first time that large, migrating fish have been shown to carry contaminants over such a great distance.

Normally, radiation and other contaminants are found in smaller fish and plankton, and only in waters close to the source of contamination. However, levels of radioactive cesium have been found at ten times the normal levels in fish off of the coast of California. The current levels, say officials, are still below the levels considered unsafe by the U.S. and Japanese governments.

In March of 2011, a massive earthquake and devastating tsunami struck northeastern Japan, killing thousands and reducing entire towns to mud and rubble. The Fukushima nuclear plant was caught unprepared for the disaster, and subsequently multiple reactors at the plant melted down, spewing radioactive materials into the air and water and triggering mass evacuations. Bluefin tuna are large, fast-swimming fish, growing up to ten feet in length and weighing up to half a ton. The fish swim at “breakneck” speeds and cross the oceans to feed and mate.

Scientists tested tuna from other regions to discover if the cesium-134 and cesium-137 found in the fish might have come from somewhere else, or if the fish had ingested plankton from water affected by the radiation leak.

Ken Woeller of the Woods Hole National Oceanographic Institute is an outside researcher who consulted by the investigation. He said the results “are unequivocal. Fukushima was the source.”

(image via WikiMedia Commons)

Underwater World: Strange Beauties of the Sea

ORIGINAL: SierraClub

The cold, dark waters of the Pacific Northwest teem with these otherworldly animals. Renowned photographer David Hall's book Beneath Cold Seas: The Underwater Wilderness of the Pacific Northwest (University of Washington Press, 2011) documents this delicate ecosystem, which is home to exotic specimens like the red-gilled nudibranch (above), a type of shell-less snail. Photo: David Hall

The sea keeps its secrets well. While humans have explored, documented, and colonized nearly every stitch of land on the planet, the vast expanse of the ocean remains mysterious. Rarely photographed underwater creatures can appear alien—their cloudlike, luminous bodies more heavenly than earthly.

The cold, dark waters of the Pacific Northwest teem with these otherworldly animals. Renowned photographer David Hall's book Beneath Cold Seas: The Underwater Wilderness of the Pacific Northwest (University of Washington Press, 2011) documents this delicate ecosystem, which is home to exotic specimens like the red-gilled nudibranch (above), a type of shell-less snail.

The inhabitants of this barely charted world may look like the stuff of science fiction, yet our lives are intertwined. Whether or not we're mindful of it, we share this planet with the nudibranch, the sea anemone, and the octopus. The strange and beautiful creatures in this photo gallery inhabit a swath of the Pacific Ocean just off the coast of British Columbia, where they face threats like overfishing, pollution, and oil tanker traffic. Our actions could forever alter the lives of these marine animals—it's time to meet our neighbors.

The candy stripe shrimp finds a safe haven beneath the tentacles of the crimson anemone. This living arrangement, called "commensalism," benefits the shrimp and causes no harm to the confection-colored anemone, whose beautiful tentacles are equipped with nematocysts, which sting and paralyze small marine critters. The unlucky prey are then guided into the anemone's central mouth—an opening which also expels waste and "births" larvae. Photo: David Hall

The enigmatic mosshead warbonnet can often be found with its head poking out of a rock crevice, a tubeworm hole, or an old shell. This particular critter was spotted in Browning Pass, in Queen Charlotte Strait. Named for its peculiar head ornamentation, the photogenic fish eats invertebrates and fish. Photo: David Hall

The fried egg jellyfish—so named for its resemblance to the breakfast dish—occasionally attracts hitchhikers. Young crabs may catch a ride on the gelatinous invertebrate's bell, some of which are 2 feet in diameter. The carnivorous jelly's nematocyst-covered tentacles can grow to be 20 feet long. Jellyfish owe their translucency to their makeup: They're 95 percent water. Photo: David Hall

The helmet crab's exoskeleton is shrouded in fine hairs, which, many suspect, help it navigate and locate objects in a dark environment. Creatures like the hermit crab are what drew photographer David Hall to the sea. "When I was ten years old, I dreamed of a career in entomology, and to this day arthropods—insects and other animals with jointed legs and an outer skeleton—hold a special fascination for me," he writes. "After mollusks, there are more species of arthropods in the ocean than any other kind of animal.". Photo: David Hall

The world's largest species of jellyfish, the lion's mane jelly's bell can grow to 8 feet and its tentacles can stretch more than 100 feet—longer than a blue whale. This particular lion's mane is a more manageable size for the blue rockfish, which maxes out at 21 inches. The rockfish eats a diet of krill, tunicates, small fish, and small plants and seems to ready to devour the jellyfish, but this scene requires a second look: "When I first saw this pair, I assumed the fish was nibbling the jelly's tissues, as sometimes happens," photographer David Hall says. "However, the detailed photographs suggest that the fish is feeding on bits of organic matter adherent to the jelly's tentacles." Photo: David Hall

The giant Pacific octopus is the largest of its kind—its arms can stretch 16 feet or more. The clever cephalopod has been known to attack sharks and even seagulls, but its more likely to nosh on scallops, crabs, shrimp, clams, or fish. A master of disguise, it can change the color of its skin to mimic corals, rocks, and plants. In captivity, the highly intelligent invertebrate has performed number of tricks, including opening jars and solving mazes. Photo: David Hall

Purple and ocher sea stars are a keystone species, keeping mussel populations in check. To feed, the starfish pries its prey's shell apart, everts its own stomach, and inserts it into the shell opening, where digestive enzymes dissolve the mussel's tissues. Photo: David Hall

A bottom-dwelling fish, the scalyhead sculpin inhabits intertidal and subtidal regions, where it lays its eggs on rocks during spawning season in the winter and spring. The territorial males guard the eggs. The three- to four-inch-long fish eats small invertebrates and sports a variety of different colors. Photo: David Hall