Monday, December 31, 2012

The Last of the Cetotheres?


Researchers have discovered that a type of whale so rare it was thought to have been extinct for 2 million years still lives.

The whale itself — the pygmy right whale — has been spotted a few dozen times. But until recently, it was thought to belong to a different, living whale family. It was only recently that scientists discovered the whale belonged to a family they once thought extinct.

The findings, published last week in the Proceedings of the Royal Society B, help explain why the pygmy right whale looks so different than other whales: it's the last living relative of an ancient species long thought extinct. The living pygmy right whale is, if you like, a remnant, almost like a living fossil, the last survivor of quite an ancient lineage that until now no one thought was around.

Based on physical evidence, the whale was thought in the past to have descended from baleen whales between 17 million and 25 million years ago. Upon studying the creatures' physical characteristics though, researchers at the University of Otago concluded that the whales are more likely to have descended from a whale family that includes the bowhead whale.

The pygmy right whale's snout is arched and frownlike, making it different from most living whales. The research team studied skull bones and other fossil fragments, ultimately coming to the conclusion that the whale was descended from a family of whales called cetotheres, which were thought to have gone extinct about 2 million years ago.   The findings are the first step toward reconstructing ancient lineage back to the point when groups first split off.


Image credit: University of Otago

Monday, November 26, 2012

The Extinction of a Species - For Soup


For the vast majority of us who have never eaten shark fin soup, or even thought of it, this may seem like a bit of a yawn. In reality, though, it is anything but.

Shark fin soup is a delicacy in China and other Asian countries meant to bring good fortune to those who eat it and to demonstrate the wealth and importance of the host who serves it. But in order to fill the bowls of this supposed delicacy, 70 million sharks are killed, indiscriminately, every year.
 
When the sharks are caught they are hauled into the boat and the fins are cut from its body. The finless shark is then thrown into the ocean, where it either drowns or is eaten by other predators. This is animal abuse of the highest order and from this perspective alone is enough to justify the ban on shark fins everywhere on the planet, but this argument also misses the real point:

When we get into a war of words about what it crueler, killing sharks versus killing pigs, chickens and cows, found in slaughterhouses all over the World, we miss the point. New proposed laws (for any species, not just sharks) are trying to address the fact that we are in the middle of the greatest mass extinction in millions of years and we humans are the cause of the vast majority of those.

If we, as a species, don't do something to protect the sharks then many of the world's shark populations are headed for extinction.

When extinction is a consequence, any tradition, no matter how entrenched in a culture, must change. This seems to demonstrate a strange conflict among us as fellow human beings. Some understand our moral responsibility not to hunt a species to extinction, where others seem totally indifferent to the consequences of killing 70 million sharks per year even when the imminent extinction of a species exists.

My plea to the people who would drive a species to extinction is to ask them to consider what they are doing to sharks and by extension to rhinos, tigers, bears and a myriad of other species that are on the brink of extinction because cultural tradition demands their rampant poaching. In other words, the poaching of endangered species will end only when the demand for those endangered species' body parts ends.

I have a fervent hope that those who currently consume endangered species' body parts will recognize that their tradition will end in one of two ways, either voluntarily while there are still sharks in the ocean, or involuntarily, when there are no more sharks, and therefore no more shark fins to fill bowls of soup.

 

Wednesday, October 17, 2012

The Surprising Sources of Your Favorite Seafoods

Article provided by: NOAA FishWatch.gov

In 2011, Americans ate 15 pounds of fish and shellfish per person. While our seafood consumption still lags far behind that of poultry, pork, and beef, it does add up to nearly 5 billion pounds of seafood per year, making the United States second only to China in seafood consumption.


In 2011, we imported about 91 percent of the seafood consumed here in the United States. However, a small portion of these imports were caught by American fishermen, exported overseas for processing and then re-imported to the United States. The remaining 9 percent was produced entirely domestically.

About half the seafood we eat is wild-caught; the other half is farm-raised, that is, from aquaculture. There's a bit of a grey area here, too, though—some "wild-caught" seafood actually starts its life in a hatchery. For example, salmon and red drum are often produced in hatcheries and then released to the wild to be caught. The same can be said for some mussel, clam, and oyster populations—in many cases, larval shellfish, or 'spat,' is reared in a hatchery and then planted in a natural setting to be harvested later. On the other hand, some "farm-raised" seafood such as yellowtail is caught as juveniles in the wild then raised to maturity in captivity.

Why does it matter? It's important to know the source of your seafood because not all of them measure up the same. Some seafood is caught or farm-raised under regulations that protect the health of the marine environment, the animals that live within it, and the folks that eat it; however, some is not. By buying seafood from reputable sources, you're helping to conserve our ocean resources and support the economies and communities that ensure our seafood supply is safe, healthy, and sustainable.

Top Ten List:


Shrimp

Shrimp
By far, shrimp remains our favorite type of seafood—Americans ate more than 4 pounds of shrimp per person in 2011. Although our shrimp fisheries are among the largest and highest valued in the United States, over 90 percent of the shrimp eaten in the United States is farmed overseas. In fact, shrimp makes up more than 30 percent of all seafood we import (by value). We mainly import shrimp from Southeast Asian countries like Thailand, Indonesia, and China, followed by Ecuador and Mexico.


Tuna


Canned tuna
We eat about 2.6 pounds of canned tuna per person per year, making canned tuna our second favorite seafood and one of our top seafood imports. Canned tuna can include several species of tuna—bigeye, skipjack, and yellowfin tunas are typically canned as "light" tuna; albacore is canned as "white" tuna. All the tuna that we eat is wild-caught; however, tuna aquaculture is moving from the research stage to the commercially-viable stage as scientists experiment and figure out the production cycle from egg to harvestable fish. More than half the canned tuna we import comes from Thailand, with smaller amounts from the Philippines, Vietnam, Ecuador, and other countries.


Salmon


Salmon
Rich in omega-3s and flavor, it's no wonder salmon has been one of our top three favorite seafoods for nearly a decade. With increased availability of fresh and frozen farmed, wild, and hatchery-reared salmon, access to this healthy, delicious seafood has increased. We ate nearly 2 pounds of salmon per person in 2011. To feed this demand, we import a half a billion pounds of salmon each year to supplement the supply that comes from our valuable commercial fisheries from Alaska to California and salmon farms in Maine and Washington State. Two-thirds of the salmon we eat is farmed, mainly imported from Norway, Chile, and Canada, with a small amount grown domestically. One-third of the salmon eaten in the United States is wild-caught, primarily in Alaska; and about half of this catch is from hatchery-reared fish released into the wild.


Pollock


Pollock
We eat about 1.3 pounds of pollock per person—most of this is wild-caught in Alaska. In fact, the Alaska pollock fishery is one of the largest, most valuable fisheries in the world. And it's often considered one of the best managed, too. Pollock is commonly used in surimi (imitation crab) and fried fillet sandwiches, but is also sold as fillets and can be a great substitute for cod.


Tilapia


Tilapia
Americans eat an increasing amount of the mild-tasting, versatile tilapia each year, nearly 1.3 pounds per capita in 2011. There's little to no commercial wild harvest of tilapia today; the tilapia we eat comes from aquaculture. In fact, tilapia is likely the first fish that was ever farmed. China supplies most of the tilapia in our markets, followed by Ecuador, Indonesia, and Honduras. We also farm some tilapia domestically.


Pangasius


Pangasius
A freshwater fish related to catfish, pangasius is climbing the chart of our favorite seafoods, up three spots from its 2010 ranking. We ate 0.6 pounds of pangasius per person in 2010, and demand for this moderately-priced fish is likely to continue to grow. Like U.S.-produced catfish, pangasius are farm-raised in ponds or cages, primarily in Vietnam, although production is growing in China, Cambodia, Laos, and Thailand.


Catfish


Catfish
Farm-raised domestic catfish has been one the top ten most frequently consumed seafood products in the United States for nearly 20 years. Catfish refers to channel catfish, native to the Southeast. U.S. catfish farmers grow this mild, sweet-tasting fish in freshwater ponds, mainly Alabama, Arkansas, Louisiana, and Mississippi. Although domestic production of catfish has decreased lately (down to 334 million pounds in 2011), it is still the top aquaculture product grown in the United States. Note that at the market, domestically grown catfish should be identified as a farm-raised product of the United States or a specific U.S. state. Imported catfish should be identified by the country of origin and the acceptable market name for the species of catfish being sold. For example, catfish species commonly raised in Asian countries should be called pangasius, basa, swai, or tra to distinguish it from U.S. farm-raised catfish, which should be marketed as catfish.


Crab


Crab

We eat a lot of rich, flavorful crab here in the United States—more than half a pound per person in 2011—and a lot of it is wild-caught in U.S. waters. From the cold waters of Alaska to the warm waters of Florida, U. S. commercial fishermen harvest several different species of crab including blue, Dungeness, king, snow, and stone crabs. The United States is a major producer of crabs with nearly 370 million pounds valued at greater than $650 million in 2011. We also import crab in a variety of forms ranging from whole crab to frozen, pasteurized, and canned, mostly from Canada, Asia, and South America.


Cod


Cod
We eat about a half a pound of cod per person every year. Two types of cod come from the United States—Atlantic and Pacific cod are closely related, but Atlantic cod is caught in New England, and Pacific cod is caught in Alaska and the Pacific Northwest. Although they can be used interchangeably, Pacific cod yield larger, thicker fillets, and Atlantic cod taste sweeter. Our Alaska fisheries for Pacific cod account for more than two-thirds of the world's Pacific cod supply. We also import some cod from China, Canada, Russia, Iceland, and Norway, some of which is farmed.

There is one commercial cod farm in the United States and researchers are developing more opportunities for domestic cod farming. Watch a video about teaching fishermen in Maine to farm cod.

Clams


Clams
A variety of clam species, both wild-caught and farm-raised in the United States, supply most of the clams we eat here. In the United States, natural production of species including surfclams, quahogs, hard clams, and soft clams remains strong and exceeds demand, and farmed production of species such as littlenecks, Manilas, and geoducks is improving and expanding. We also import clams from Asian countries and Canada, which may be a mix of wild-caught and farmed.

Source: NOAA  http://www.fishwatch.gov/farmed_seafood/index.htm 

Wednesday, October 10, 2012

Restoring the Urban Sea by Farming It - By Barton Seaver

With 91% of the seafood that we eat in this country imported from foreign waters there is increased interest in restoring local watersheds to full productivity. While much of the dialogue about sustainable seafood focuses on maintaining adequate resources, some forms of aquaculture can actually help to regenerate ecosystems, revitalize economies, and enhance food security.

This is what I term restorative seafood; food systems that provide for our needs while actually increasing the productivity and profit of the waters that sustain us. Shellfish farming in particular — clams, mussels, and oysters — are some of my favorite examples of man’s ability to actually give back to the planet even while providing for our needs....

Read More: Restoring the Urban Sea by Farming It

Wednesday, October 3, 2012

Are Aquapods the Fish Farms of the Future?

Hawaiian mariculture firm Kampachi Farms’ Velella Project is now raising fish in open-ocean “Aquapods” with virtually no negative environmental effects.

alttext
Fish farming in estuaries and protected waters may seem to offer a more sustainable alternative to traditional deep-sea fishing, but it still causes effluent accumulation and interactions with wild stocks that can disrupt the surrounding environment. That’s according to Hawaiian mariculture firm Kampachi Farms, whose Velella Project is now raising fish in open-ocean “Aquapods” with virtually no negative environmental effects.

In an effort launched last year, marine biologists at Kampachi Farms have been raising hatchery-reared, native Kampachi fish in a 22-foot Aquapod tethered to a manned sailing vessel in the deep open ocean near the Big Island of Hawaii. The fish are fed a sustainable diet that has replaced significant amounts of fishmeal and fish oil with soy and other sustainable agricultural proteins, the firm says. The setup drifts in eddies off the west coast of the Big Island in Federal waters from three to more than 150 miles offshore and 12,000 feet deep. Marine biologists on board monitor and feed the fish while a GPS system tracks the vessel’s drift and transmits data to land-based research headquarters; the tender vessel’s engines are used minimally to correct course. The results are exciting so far, the fish are healthy, growing well and are where they’re meant to be – in the ocean. This technology has the potential to revolutionize fish farming, making it the most impact-free form of food production on the planet.” The video below explains the effort in more detail:



With support from a wide range of organizations including NOAA, the National Science Foundation, the Illinois Soybean Association, Lockheed-Martin, the International Copper Association and Ocean Farm Technologies, the Velella Project has made its environmental monitoring data available for public access on its site. Sustainability-minded entrepreneurs around the globe: one to get involved in?

Website: www.kampachifarm.com/offshore.html
Contact: info@kampachifarm.com

Wednesday, June 27, 2012

The Lamprey's Beauty Runs More Than Slime-Deep

Recently on twitter I started following a enterprising Pacific Lamprey named Luna on her journey to spawn. To be clear I don't usually follow any creatures other than my fellow man, but the plight of the Pacific Lamprey has gone largely unnoticed due perhaps to its - shall we say - less than perfect smile.

Not only are its numbers dwindling, but this misunderstood, eel-like fish also suffers the indignity of being unfairly maligned as a junk fish.

While it is true the non-native sea lamprey is causing problems in the Great Lakes, the West Coast varieties shouldn't pay the price for a distant cousin's damage.

In all, about 50 species of lamprey exist, but the one that so plentifully populated the Columbia River and its tributaries is called the Pacific Lamprey.

But numbers alone never earned the Pacific lamprey the respect it deserves. Its reputation as a blood-sucking parasite probably hasn't helped, neither has its appearance, which is something like a cross between a banana slug and a jungle leech with teeth [lots of teeth].

 But even blood-sucking parasites have their place in nature's plan. As more is known about the lamprey, it's clear this homely creature has a role that's far more complex than first impressions would indicate.

Not enough Pacific lampreys remain to adequately fill the species' niche. Counts of Pacific Lamprey at Ice Harbor Dam dropped from 50,000 in the early 1960s to fewer than 1,000 during the 1990s. Counts on the North Umpqua River in Oregon had declined from about 47,000 in 1966 to fewer than 50 a year since 1995.

When the species was plentiful, juvenile lampreys fed on bits of plant material in numbers sufficient to help keep rivers running clear. After spawning, the carcasses replenished nitrogen levels and other nutrients in freshwater streams.

It's true that in their oceangoing blood-sucker stage, Pacific Lampreys attach themselves to salmon and other fish, which sometimes weaken and die as a result. But when the slow-moving Lampreys numbered in the millions, they also provided a salmon substitute for sea lions and other predators, filling the bellies of these would-be salmon killers. The net effect was beneficial.

Traditionally, Mid-Columbia tribes harvested lamprey, using their dried meat for subsistence, ceremonial and medicinal purposes, but not enough of the fish remain. The Confederated Tribes of the Umatilla Indian Reservation are working to restore the Pacific Lamprey as a way of also preserving their Indian culture.

Both are noble goals. So is following Luna's journey - @LunaTheLamprey

Thursday, June 21, 2012

NE Fish Council Votes For Oversight of Large Trawlers Scooping Up River Herring

The fate of the river herring in Maine and along the Atlantic coast was solidly in the hands of the New England Fishery Management Council (NEFMC), who gathered in Portland this week.

By midday Wednesday, they had voted to send a recommendation to the National Marine Fisheries Service (NMFS) to require strict oversight on large mid-water trawlers working three miles off the coast and up to 200 miles out to sea.

More decisions affecting river herring were expected by late in the day. NMFS is likely to act on the NEFMC recommendations before the end of the summer.Recreational and commercial fishermen, among others, have pointed to the need for strict oversight of the large mid-water trawlers that target Atlantic sea herring inshore but also scoop up marine mammals, haddock, and river herring as unintended bycatch.

Alewives and blueback herring, collectively known as river herring, spend most of their lives at sea and have been on the decline for decades, in spite of efforts to improve habitat and build fish ladders so spawning fish can make their way from the sea to freshwater in the spring.

Fishing for river herring is illegal in Massachusetts, Connecticut, Rhode Island and North Carolina. The fish are currently under review for listing under the federal Endangered Species Act, with a recommendation for or against listing expected this summer.

Like their sea-dwelling cousins, river herring are an important food species in the marine food web, providing food for groundfish, stripers, tuna and others. At sea, river herring often school with Atlantic herring.

Atlantic mid-water trawlers, with a fleet numbering around 40 boats, are among the largest boats fishing in federal U.S. waters today. Mid-water trawlers, such as those operated by O'Hara Corporation in Rockland, tow submerged cone-shaped nets through the midsection of the water column that funnel schooling fish towards the small end of the net, known as the cod end. Working in pairs, with one larger net being pulled behind two boats, trawlers can work an area in a grid pattern, catching up to 1,000,000 pounds of fish in one haul, with the potential to clear out a local river herring population in a day.

There have been no bycatch limits on how many river herring can be caught. Catch caps may be set late Wednesday.

On Wednesday, NEFMC voted to require all mid-water trawlers to carry a scientific observer on board to keep track of bycatch numbers, with industry and the federal government sharing the cost. If NMFS approves this requirement, it is likely to be implemented in spring of 2013.


Source: New England Fishery Management Council

Thursday, May 17, 2012

U.S. Fisheries Continue to Improve

The latest numbers on the status of fisheries in the United States, released on Monday by the National Oceanic and Atmospheric Administration (NOAA), show continued progress toward ending overfishing.

si-fish-graph.jpg
Credit: Pew Environment Group, Data by NOAA

Six stocks that were previously overfished have been declared rebuilt—having reached a healthy population size—the biggest improvement since NOAA began issuing the reports in 1997. That raises the total number of rebuilt stocks to 27. "This is evidence that we are moving in the right direction and that sacrifices that fishermen have made are paying off," says Lee Crockett of the Pew Environment Group.

All told, 86% of the 258 major stocks reviewed by NOAA are in good shape.

But more remains to be done. Forty-five stocks remain overfished (the population is below the target) and 36 others are still "subject to overfishing," or, in other words, being caught at too high a rate. Both of these metrics, however, improved slightly from the previous year.

In a teleconference, Galen Tromble of NOAA's Office of Sustainable Fisheries credited the gains to the annual catch limits required by federal law and the rebuilding plans implemented by regional fisheries councils.

The six stocks now ready:


Source:  National Oceanic and Atmosperic Administration  (NOAA)

Monday, May 7, 2012

Dwarf Seahorse Needs Protection

The one-inch long dwarf seahorse may be threatened with extinction by lingering pollution from the Deepwater Horizon oil spill, loss of habitat and overzealous collectors, according to findings by the U.S. Fish and Wildlife Service.

The USFWS is now beginning a 12-month status review to determine if listing the species under the Endangered Species Act is warranted.

The Center for Biological Diversity's listing petition claims that 90 percent of the seagrass habitat off the coast of Florida has been lost since 1950.

 It is also cited that massive die-offs of seagrass and seahorses across the Gulf Coast due to ocean acidification from global warming and the damage caused by boat propellers and shrimp trawlers to be mitigating factors.

The public has until July 3 to comment on the USFWS 90-day finding on the petition. The USFWS will announce a public comment period for the species review at a later date. I will keep you updated.

Wednesday, May 2, 2012

Thank You

Thanks to all my readers for hanging in there as I change my blogs location and format. Your patience is really appreciated!

Tuesday, May 1, 2012

How Much Is Too Much?

At the Offshore Technology Conference that opened Monday in Houston, a presentation focused on a plan to drill the deepest offshore well ever — a scientific project set for 2017 that will break into the seafloor under more than two miles of water.

While the well, which is aimed at retrieving a core of the Earth's mantle, will not produce oil, it will break the record for offshore drilling with a riser — a pipe used in oil drilling that reaches from the rig to the seafloor.

If successful, the accompanying innovations in drilling also could bring energy companies into contact with life and ecosystems even more obscure and less understood than the frontiers they already explore.

So when is it too much?

Pushing deeper underwater could endanger little-understood creatures such as the deep-water corals that were damaged after the Gulf of Mexico oil spill two years ago.

How sad would it be that these oil companies are going to be the first ones maybe to get anywhere near new species of corals and as of yet undiscovered marine life. Ultimately if they're not careful, they may also be the last.

For years the offshore industry's pursuit of oil has pushed drillers farther into the deep, bringing heavy machinery and remote-operated vehicles into some of the most alien reaches of the globe.

Already, oil companies have been scientific observers during deep-water operations. During Shell's development of its Perdido project 200 miles south of Freeport, a camera on an unmanned submarine captured the first images of an obscure creature in its natural habitat: a big-fin squid at a depth of about 6,399 feet below the surface. The Perdido project, which contains the world's deepest producing well at 9,267 feet, was also where workers operating another unmanned submarine spotted a Greenland sleeper shark 8,530 feet under water. The shark previously was thought to stay within 2,000 feet of the surface.

Source: mysanantonio.com/


Thursday, April 26, 2012

Marine biologist turned game designer ‘World of Warcraft’

Photo by Gary Moss
Greg Street is a former marine biologist who became lead systems designer for the online hit “World of Warcraft.” He will speak at McDaniel College on Monday.<B><I></B></I>Life as a marine biologist was not quite the splash Greg Street thought it would be. In the late 1990s, he spent years going through school only to find that studying the environment at times meant spending little of it in nature. Bored by the administrative side of his career, Street looked to video games instead.

“I ultimately [decided] if I was going to spend so much of my time in front of a computer, I may as well be playing computer games instead of writing grant proposals.”

Street managed to arrange an interview with Ensemble Studios, which was planning to release the real-time strategy game “Age of Empires.” Although a gamer at heart, Street had little knowledge of the intricacies of design.

“They wanted a sample of my work and I had never made anything, so I stayed up all night making levels for the game they were working on and they really liked it,” Street says.

On Monday, Street will speak at McDaniel College as part of its SmartTALK series, which brings accomplished alumni back to campus for a public chat with president Roger Casey. Street will discuss how his liberal arts education served him.

Street graduated from the school in 1991 with degrees in biology and philosophy, and then earned his doctorate at the University of Texas. McDaniel became Street’s number one pick on a lark. His original pick was Columbia, but Street’s grandfather was a McDaniel alumnus, who asked him to apply. Street did apply and the more he learned about the school, the more he was enticed by the notion of attending.

“I just got this sense that they really wanted me and they would be excited about my being there and, ultimately, that was where I wanted to be,” Street says.

He says the school prepared him not only for graduate school, but also how to approach and interact with his professors without apprehension.

“I feel like there’s a real quality of learning that could occur in that environment that you just couldn’t get in a larger state school. And I feel like interactions like that gave me a lot of self-confidence that when I went to graduate school [I could] try to talk to professors ... as people,” Street says.

After working at Ensemble for a decade, Street joined Blizzard Entertainment in 2008. In addition to “World of Warcraft,” the company is known for its massive franchises “StarCraft” and “Diablo.” Street says a business toss-up at Ensemble and the studio’s impending closing prompted his decision to leave.

“I worked at Ensemble for almost 10 years. About halfway through that, the studio was acquired outright by Microsoft, which was super exciting at the time,” Street says. “But it seemed to me that over the years Microsoft was placing less emphasis on PC gaming.”

Once Street joined Blizzard, he became lead systems designer for the massive multiplayer online role-playing game hit “World of Warcraft.” As Street says he tells new employees, he enjoys working at the company.

“This would be a fantastic place to work even if we made light bulbs or batteries,” Street says. “The fact that we make games is icing on the cake.”

At Blizzard, Street says he emphasizes more overlap between developers and designers.
“Blizzard tries to avoid what we call ‘the grand reveal," Street says. That’s where a designer sits and works on something and says, ‘A-ha, there it is.

Science itself also plays a role in Street’s work. He says he regularly interacts with fans on forums or at conventions for feedback. They also test complaints, create statistics and rely on numbers as much as possible.

For Street, science and video games share some of the same philosophies, a lesson he began to appreciate while studying at McDaniel College.

“Scientists learn early on how to fail,” Street says. “You make a ton of mistakes. You set up an experiment and the experiment fails or you have a theory and you’re totally wrong.”

Source: gazzette.net

Wednesday, February 15, 2012

Mysterious Life Forms in the Extreme Deep Sea

Dropcam' and other deep-sea instruments reveal strange creatures of the dark deep during expedition to Mariana Trench.

A summer research expedition organized by scientists at Scripps Institution of Oceanography at UC San Diego has led to the identification of gigantic amoebas at one of the deepest locations on Earth.

During a July 2011 voyage to the Pacific Ocean's Mariana Trench, the deepest region on the planet, Scripps researchers and National Geographic engineers deployed untethered free-falling/ascending landers equipped with digital video and lights to search the largely unexplored region. The team documented the deepest known existence of xenophyophores, single-celled animals exclusively found in deep-sea environments. Xenophyophores are noteworthy for their size, with individual cells often exceeding 10 centimeters (4 inches), their extreme abundance on the seafloor and their role as hosts for a variety of organisms.

The researchers spotted the life forms at depths up to 10,641 meters (6.6 miles) within the Sirena Deep of the Mariana Trench. The previous depth record for xenophyophores was approximately 7,500 meters (4.7 miles) in the New Hebrides Trench, although sightings in the deepest portion of the Mariana Trench have been reported. Scientists say xenophyophores are the largest individual cells in existence. Recent studies indicate that by trapping particles from the water, xenophyophores can concentrate high levels of lead, uranium and mercury and are thus likely highly resistant to large doses of heavy metals. They also are well suited to a life of darkness, low temperature and high pressure in the deep sea.

"The research of Scripps Professor Lisa Levin (deep-sea biologist) has demonstrated that these organisms play host to diverse multicellular organisms," said Doug Bartlett, the Scripps marine microbiologist who organized the Mariana Trench expedition. "Thus the identification of these gigantic cells in one of the deepest marine environments on the planet opens up a whole new habitat for further study of biodiversity, biotechnological potential and extreme environment adaptation."
The xenophyophores are just the tip of the iceberg when it comes to considerations of the nature and diversity of life at extreme depths. For example, according to Dhugal Lindsay (Japan Agency for Marine-Earth Science and Technology, or JAMSTEC), the Dropcam movie also depicts the deepest jellyfish observed to date.

The instruments used to spot the mysterious animals were "Dropcams" developed and used by National Geographic Society Remote Imaging engineers Eric Berkenpas and Graham Wilhelm, participants in the July voyage.

"The 'Dropcams' are versatile autonomous underwater cameras containing an HD camera and lighting inside of a glass bubble," said Berkenpas. "They were created by National Geographic engineers to allow scientists and filmmakers to capture high-quality footage from any depth in the ocean. The devices were baited and used 'camera-traps' to capture imagery of approaching marine life."

Dropcams utilize a thick-wall glass sphere capable of withstanding more than eight tons per-square-inch pressure at extreme depth.
"Seafloor animals are lured to the camera with bait, a technique first developed by Scripps Professor John Isaacs in the 1960s," said Kevin Hardy, a Scripps ocean engineer and cruise participant. Hardy advanced the ultra-deep glass sphere design used on 'Dropcams' more than a decade ago. "Scripps researchers hope to one day capture and return novel living animals to the laboratory for study in high pressure aquariums that replicate the trench environment."

Also during the expedition, Scripps researchers successfully tested an advanced seafloor Deep Ocean Vehicle (DOV) design, using similar spheres to recover microbes and test other advanced system components.

The xenophyophore sightings were positively identified by Scripps' Levin, director of the Scripps Center for Marine Biodiversity and Conservation, and confirmed by Andrew Gooday of the UK National Oceanography Center.

"As one of very few taxa found exclusively in the deep sea, the xenophyophores are emblematic of what the deep sea offers. They are fascinating giants that are highly adapted to extreme conditions but at the same time are very fragile and poorly studied," said Levin. "These and many other structurally important organisms in the deep sea need our stewardship as human activities move to deeper waters."

This project was funded by NASA, the National Geographic Society Expeditions Council, Joanie Nasher, Patty and Rick Elkus.

Photo credit: Lisa Levin (all except upper right, credit David Checkley)


Source: Scripps Institution of Oceanography at University of California, San Diego

Friday, January 6, 2012

An Ocean Short of Oxygen

As average global temperatures rise, larger parts of the world's oceans could become anoxic dead zones. This is shown by an analysis of the oxygen conditions during the past 20,000 years

Every summer, a few places in the north-east Pacific now see vast numbers of dead marine animals including fish, shrimp or molluscs being washed up on the beach by the waves. It is a financial catastrophe for the local fishing industry and an ecological one for the sea. These mass mortalities are caused by the animals suffocating because their water contains too little oxygen, or even none at all.
Although this phenomenon is still localised, that could change in the future, as revealed by a new publication in “Nature Geoscience”.

The two authors, Samuel Jaccard from the Geological Institute at ETH Zurich and Eric Galbraith from McGill University, Canada, have evaluated oxygen data from seafloor sediment cores. Based on this data, they have reconstructed how the oxygen content in the oceans throughout the world has changed in the past 20,000 years, focusing particularly on the Pacific and Indian Oceans.

When temperature rises, oxygen vanishes

Their analyses show that the marked average global temperature rise of around two degrees centigrade occurring between the peak and the end of the last ice age, i.e. 20,000 to 10,000 years ago, had a massive effect on the oxygen content of seawater. The oxygen content of many oceans fell dramatically as a result of the temperature increase, and oxygen-depleted marine zones expanded more than during the cold period.

Expansion of the dead zones

These dead zones are particularly critical because they are situated in areas of the ocean that are home to the largest quantity of life. This means a shrinkage of habitat especially for the large fish of the open ocean. Entire food chains are threatened with deprivation. Biodiversity in the oceans will probably decrease, which will also pose serious problems for the fishing industry.

Poor mixing

The oxygen in seawater originates mainly from gas exchange between the sea surface and the atmosphere. Algae and other green life-forms also produce the vital gas. However, oxygen is consumed when dead organic material sinks down towards the sea bed and is degraded in the process by various organisms, mostly microbes. Warmer temperatures in the uppermost layers of water disturb this delicate equilibrium, because for physical reasons warm water is able to absorb less oxygen than colder water.

Furthermore, more stable layers form when seawater warms up. Warm, lower-density water lies on top of cold, denser water. These layers scarcely intermix, reducing the efficiency of the gas exchange with the atmosphere and between the various bodies of water.

Reference: Jaccard SL & Galbraith ED. Large climate-driven changes of oceanic oxygen concentrations during the last deglaciation. Nature Geoscience (2011). Published online 18 December 2011. DOI: 10.1038/ngeo1352

Source: ETH Z├╝rich