News Home Video Gallery Newsletters Photo Gallery Cruising Int
Sail-World.com : Uncovering the ocean's biological pump
Uncovering the ocean's biological pump

'To prevent contamination of their samples, WHOI scientists Phoebe Lam and Dan Ohnemus work inside a plastic bubble lab set up inside their ship. Filters pump clean air into the plastic bubble and keep the space at positive pressure. So if there is a leak in the bubble, clean air will leak out, rather than contaminated air leaking in.'    Chris Linder

Dan Ohnemus clearly remembers the highlight of his fourth-grade class in Bourne, Mass. He and his classmates made a satellite call to scientists at Woods Hole Oceanographic Institution (WHOI) who were off the Galápagos Islands testing a new generation of remotely operated vehicles (ROVs).

'For a little kid who was interested in science, it was awesome to have a satellite link to a ship somewhere on the other side of the world,' Ohnemus said.

He worked hard on his follow-up assignment, a diorama of hydrothermal vents on the seafloor. For the culminating event, the class was invited down the road to WHOI to see scientists actually remotely operating an ROV near the seafloor—in real time, from the auditorium in Redfield Laboratory.

Dan Ohnemus unloads pumps that have sucked in seawater samples containing particles floating in the ocean. He analyzes those particles to reveal the movement of chemicals in the ocean. -  Chris Linder  


'I sit in that auditorium all the time now for lectures,' said Ohnemus, before he earned his Ph.D. in February 2014 from the MIT/WHOI Joint Program in Oceanography. 'But I can remember being in there as a nine-year-old.' He and his classmates were packed into the darkened, cavernous room with a live view of the seafloor projected on a towering screen before them. They buzzed with excitement as they watched the ROV Jason maneuver around a field of seafloor vents. Ohnemus, laughing, can still recall the stab of jealousy he felt when another kid was picked to try driving Jason by remote control.

As it turned out, that day in Redfield wasn’t his last chance to peer into a vent field or go to sea himself on a scientific expedition.

The path to the ocean

Ohnemus is the son of a lobsterman whose working boat is tied up among the dories bobbing in Quissett Harbor in Woods Hole near WHOI. As a kid, Ohnemus would join his dad setting traps in Buzzards Bay.

'I loved going out with him on the boat. I loved to steer. In the summertime I would paint buoys for him.'

He even helped his dad monitor water quality at trap sites, as a volunteer for the Buzzards Bay Coalition, doing simple titrations to determine if the water had a healthy amount of oxygen. But fishing as a career seemed fraught with challenges, from the hard labor to frustrating licensing bureaucracy and unexpected diseases that ate away at lobster shells.

A self-described 'science kid,' Ohnemus cracked open rocks and science books from a young age. At Williams College, he earned double majors in biology and chemistry and then took a break after his rigorous studies to work construction back home in Bourne.

Eventually, science called him back. He answered an ad for a job at WHOI with geochemist Jim Moffett, who was studying trace elements such as iron. These elements are essential for marine life, but they are not evenly distributed in the ocean and are often in limited supply. So understanding where and why trace metals appear in the ocean is a key ingredient to explaining where and why life does or doesn’t thrive in the ocean.

Boy in the bubble

As a Research Assistant, Ohnemus learned how to measure vanishingly small amounts of iron and other elements in seawater—from big, rusty metal ships that continually produced metal particles that would ruin their hard-won water samples. To prevent contamination, the researchers build a plastic bubble lab inside the ship to work in.

'When I was a little kid my sister and I used to build forts out of clotheslines and towels,' he said. 'So when I went to sea and had a box of clothesline and plastic and had to essentially build a pressurized ‘fort,’ it was the most natural thing I’ve ever done!'

Filters pump clean air into the plastic bubble and keep the space at positive pressure. So if there is a leak in the bubble, clean air will leak out, rather than contaminated air leaking in. Work tables and all metal surfaces are covered in plastic, and hairnets, booties, and gloves are de rigueur. Scientists can then work confidently uncontaminated inside the bubble, as the outside surface becomes coated in a film of grime, tiny bits of rusted paint, and flecks of sand from the floor.

Dan Ohnemus, who earned his Ph.D. at WHOI in 2014, is now a postdoctoral scientist at Bigelow Laboratory for Ocean Sciences in Boothbay, Maine (which isn’t quite as snowy and cold as Antarctica, where this photo was taken). -  Phoebe Lam  


Particles paint the picture

Ohnemus brought his training in trace-element chemistry with him when decided to pursue a Ph.D. in the Joint Program. But he switched from studying elements dissolved in seawater to the elements that attach to particles that drift and sink in the sea.

The ocean is full of these 'particles,' which is a catch-all term for everything from sand that blew into the ocean from deserts, to living cells or their skeletal remains, to pellets of poop sinking downward. Particles can be alive, dead, clumped, decomposed, repackaged, or solid rock. If you can catch it on a filter, it's a particle.

Ohnemus and his advisor, WHOI marine chemist Phoebe Lam, divide the particles they study into two groups, either greater or less than 50 microns, which is roughly half the diameter of a human hair. The particles’ tiny size, however, belies the major role they play in the ocean.

'Particles are like the tractor-trailers and trucks of the ocean,' Ohnemus explained. 'They are moving stuff around, all the time.'

Like the tractor-trailers that distribute food from farms to hungry humans, particles in the ocean transport nutrients to depleted areas. They can also transport the equivalent of luxury goods: micronutrients such as iron that are difficult to come by in the ocean but essential for the growth of tiny phytoplankton. Considering that about half of Earth’s oxygen is produced by photoplankton at the ocean surface, figuring out what factors regulate where and how well they grow is critical to figuring out how our whole planet operates.

'They are called ‘trace’ elements because they are found in small, that is, ‘trace,’ quantities.' Lam said. 'But their name also could easily be attributed to the fact that many of these elements are useful to ‘trace’ the movement of water masses and particles in the ocean.'

'The stuff inside the trucks is what matters,' Ohnemus said, 'but sometimes you need to study the trucks themselves, their patterns, to see where they are coming from and how they are getting where they go.'

Filtering seawater, marine geochemists obtain samples of particles floating in the ocean. The particles transport chemicals through the ocean, even to great depths. -  Chris Linder  


A particular type of evidence

To measure particles at sea, Lam and Ohnemus literally vacuum them out of the water. They wrestle 150-pound, bellybutton-high, battery-operated pumps onto a wire and lower them down to various depths in the ocean. Typically they investigate particles from surface waters down to at least 3,280 feet (1,000 meters) below. Each pump sucks in more than 265 gallons (1,000 liters) of seawater through a filter that captures all the particles.

When the pumps are brought back on deck, the pump head containing the filter is brought to the bubble. Gloves, lab coats, and booties are donned, the filter is withdrawn from the pump with tweezers, the salts are rinsed off, and the filter is set to dry in an oven. The material collected on the filters will range from rusty brown to green, depending where in the world the scientists are sampling. Finally, the filters are bagged and boxed to be analyzed back on land.

'It’s definitely strange,' Ohnemus said. 'We spend days and days collecting these filtered samples, and they can all come back in a backpack.'

Back on land, the work really begins. As part of his Ph.D. thesis, Ohnemus developed an analytical procedure to measure 23 different trace elements in particles. The filters, with the particles on them, are completely dissolved with strong acids, and the resulting solution is run through a mass spectrometer to measure the abundance of each element present in the samples.

Priming the pump

The amount of data they generate is gargantuan: On a single research cruise, there may be dozens of locations where they stop to take 16 particle samples spanning a range of depths in the water below the ship. Ohnemus measured his 23 trace elements from every sample, and Lam examined the organic carbon, calcium carbonate, and opal (a silica mineral) in them.

Together, these trace elements elucidate the movement of particles, which, in turn, take part in a process hidden in the ocean on which our whole planet depends. Scientists call this process the 'biological pump,' because it is driven by life in the ocean.

It works like this: In sunlit surface waters, plankton take up carbon dioxide absorbed by seawater from the atmosphere. Using photosynthesis, they convert it, just as plants on land do, into organic carbon for their cells. They grow, die, and sink—carrying the organic carbon with them and thus 'pumping' carbon from the atmosphere to the deep ocean.

The biological pump plays a key role in regulating Earth’s climate, because carbon dioxide is a heat-trapping gas that is warming up our planet. 'The efficiency of the biological pump,' Lam said, 'is a battle between how quickly the particles can sink versus how quickly microbes can decompose the organic carbon back to carbon dioxide.'

Typically, big particles made of aggregated cells sink faster, efficiently transporting organic carbon to deeper waters or sediments on the seafloor. Fast-sinking particles are better able to usher carbon to a long-lasting burial at sea.

But if particles sink slowly and linger in the upper layers of the ocean, this gives microbes more time to hijack the particle-trucks and remove desirable trace elements. The microbes turn the organic carbon back into carbon dioxide, where it easily returns to the atmosphere and contributes to further global warming. 'The microbes effectively cause a leak in the pump,' Lam said.

Hither and yon through the oceans

The biological pump functions quite differently in different parts of the oceans, and getting a global view is key to figuring out how the pump and its impact on Earth’s climate may shift in the future.

'Considering how big the ocean is and how important it is to the planet, the most surprising thing for me is how few people are studying it,' Ohnemus said. 'The oceans occupy 71 percent of the planet’s surface, and there’s just a really small, collegial, well-functioning group of people out there studying it.'

Global surveys of trace elements in the ocean aren’t something that any one institution or country has the resources to take on. Ohnemus and Lam are part of an international project called Geotraces, involving scientists from about 35 nations who are working together on systematic oceanographic cruises to measure and study a wide spectrum of elements, isotopes, and chemicals in oceans around the world. Lisbon, Cape Verde, Bermuda, Durban, Perth, and McMurdo Station in Antarctica are a just a few of the ports of call Ohnemus has made crisscrossing oceans on Geotraces and other cruises and measuring trace metals.

'Geotraces gets all these people measuring things together—talking together, taking the same samples from the same place at the same time,' Lam said. 'You start putting the puzzle pieces together, to see whether your measurements and theories work with everyone else’s. I didn't fully appreciate how amazing that would be until we started talking to our colleagues and realizing that it does, in fact, all come together.'

To measure particles at sea, marine geochemist Dan Ohnemus and colleagues literally vacuum them out of the water. They wrestle 150-pound, bellybutton-high, battery-operated pumps onto a wire and lower them down to various depths in the ocean -  Chris Linder  


Assembling the puzzle

An example of the puzzle pieces aligning came when a Geotraces cruise passed over the Mid-Atlantic Ridge, a chain of volcanic undersea mountains running down the middle of the ocean. Along the ridge, hydrothermal vents spew mineral-rich fluids out of the seafloor like undersea geysers.

As Lam and Ohnemus collected particles, their colleagues analyzed chemicals dissolved in seawater inside and outside the plumes of fluids emanating from the vents. They revealed a picture of the interacting chemical process at play.

The vent plume was the only place in the Atlantic Ocean where particles were rich in iron oxides. They were formed when iron-rich vent fluids hit oxygen-rich seawater. Meanwhile, colleagues measuring dissolved thorium in seawater found a ghostly absence of them within the vent plumes. Together, they deduced that the chemically reactive iron oxides bonded with thorium, mopping it out of the ocean like a sponge.

Every advance like this in understanding the chemistry of our oceans, even those that people consider esoteric, can be valuable, Ohnemus said. 'Who knows what knowledge we're going to need to fix, or even predict, what's going on with climate change? Even though today, tomorrow, next week, it might not be immediately obvious, the knowledge that we get from studying the ocean is going to be really important over time.

'And it is cool to be even a small part of that,' he said. 'You are really lucky to be an oceanographer.'

Now a postdoctoral scientist at Bigelow Laboratory for Ocean Sciences in Boothbay, Maine, Ohnemus hasn’t lost the sense of wonder he had as a fourth-grader. In the middle of a cruise in the Ross Sea off Antarctica in February of 2011, he grabbed a big cup of coffee to prepare for a 5:30 a.m. phone call to the other side of the world. The satellite phone connection was sketchy, but it held up long enough for him to answer questions from students following the scientific adventure from their high school in Roselle Park, New Jersey.

Dan Ohnemus's research was supported by the National Science Foundation's Division of Ocean Sciences and the NSF's Office of Polar Programs, a Williams College Tyng Fellowship, and The J. Seward Johnson Fund and the Stanley W. Watson Student Fellowship Fund at WHOI.


by Elizabeth Halliday WHOI


  

Click on the FB Like link to post this story to your FB wall

http://www.sail-world.com/index.cfm?nid=121821

4:17 AM Fri 2 May 2014GMT


Click here for printer friendly version
Click here to send us feedback or comments about this story.







Cruising USA

Michael Thurston, the owner of the Australian yacht Drina, sent us a message from Nome, Alaska, to inform us that he and his crew had reached the Pacific Ocean thus successfully completing a transit of the Northwest Passage. A late opening of the Bellot Strait allowed Drina to reach the central part of the Northwest Passage only by mid-September. ... [more]  

The World ARC fleet departed the Cocos (Keeling) Islands this morning, embarking on the second longest sail of their circumnavigation; a 2350 nautical miles journey to Mauritius. Their stay in the tropical atoll has certainly been one to remember. ... [more]  

Pantaenius, the world’s leading specialist yacht insurance company, has been at the forefront of yacht insurance for more than 40 years, earning a reputation for transparency and commitment to customer service that provides round-the-clock international support and reliable, speedy claims settlement. ... [more]  

How to make a distance scale for faster navigation by Captain John Jamieson, Florida
If you are anything like me, sailing navigation can be a challenge when short- or single-handed sailing. But you still need to be able to plot fast and accurate positions for sailing safety. Here one little-known sailing tip used by the pros that will help you do just that! ... [more]  

The 14th edition of the Atlas also includes a new double page map of the Arctic Ocean, which highlights the dramatic long-term decline of Arctic sea ice cover. The sub-ice maps draw on bedrock data, provided by the British Antarctic Survey, to show physical features which are obscured by ice cover. ... [more]  

On Monday 22 September the EU Naval Force flagship, ITS Andrea Doria, met the Chinese Navy ship, CNS Changbaishan, in the Gulf of Aden. ... [more]  

The Presque Isle peninsula is a 3,200-acre – 7-mile long arm that extends northeast into Lake Erie creating a large, sheltered boating paradise of a harbour. With a string of well equipped marinas, a wealth of facilities and a very impressive yacht club, it has attractions for boaters that place it at the top of a cruising destination list. ... [more]  

In the early morning of Friday 19 September, EU Naval Force frigate, ESPS Navarra, came to the aid of a stricken yacht in the Gulf of Aden. The yacht had been detected on the warship’s radar in the early morning. ESPS Navarra’s Bridge team initially tried to hail the yacht via their VHF radio. ... [more]  

As their annual migration south approaches, sail and powerboat cruisers are stocking their boat’s lockers, checking systems and taking inventory of spare parts. But that’s not the only preparation these cruising 'snowbirds' will need to do, says Boat Owners Association of The United States (BoatUS). ... [more]  

Lost your rudder at sea? Michael Keyworth perfected a way to steer using drogues. To engineer this solution, he removed the rudder from his own boat(!), and experimented with different method, and has summarized his technique in this terrific article. ... [more]  

You scratched my seagrass! by Steven Katona, Newport, RI
Sailors for the Sea publishes monthly articles that translate the language of marine science into fascinating articles about ocean health. ... [more]  

Following a relatively short stopover in Christmas Island, eleven of the World ARC fleet have now arrived in their next paradise, the Cocos (Keeling) Islands. From first settlement in 1826 by English merchant Alexander Hare, through decades of administration by the Clunies-Ross dynasty, most island inhabitants had little freedom or contact with the outside world. ... [more]  

Paul Whitehouse and Simone Wood, from Wolverhampton and London, were in La Paz in Baja California when Hurricane Odile hit the Baja California peninsula last Sunday. It is thought their yacht overturned, and the couple have not been seen since. The couple is thought to have been living in La Paz for around a year. Mr Whitehouse is believed to be a scuba diving instructor in the city. ... [more]  

This might be the Texting and Facebook generation but boaters need to use VHF radio says volunteer rescuers from Weston-super-Mare's lifeboat station who rescued a yachtsman whose boat sank in the middle of the Bristol Channel and who then texted his girlfriend. ... [more]  

Earlier this year two men died in their bunks of carbon monoxide poisoning caused by the highly toxic fumes given off from a poorly maintained butane gas cooker. The cooker which was located in the wheelhouse had been lit to heat the wheelhouse and sleeping area. A carbon monoxide alarm was not fitted. ... [more]  

The Arctic is an ocean surrounded by land and Arctic sea ice is the thin layer of frozen ocean water that forms and grows during the winter, and melts in the summer. Dr Jeremy Wilkinson from the British Antarctic Survey provides a scientist’s perspective on the trend for decreasing Arctic sea ice. ... [more]  

The Virgin Islands are an archipelago. That part, which is a British overseas territory, is commonly referred to as the BVI. About 30,000 people live in the BVI, most of which live on the island of Tortola. The BVI are comprised of about 50 islands the majority of which are not inhabited by humans. ... [more]  

The Galley Guys take on the Vancouver International Boat Show by Greg Nicoll with Frank Leffelaar and Friends
The Galley Guys hit the Vancouver International Boat Show running. All day long, we were checking out new boats, looking into ice lockers, peeking into storage compartments, seeing what’s new for gourmet cooking onboard and being forced to live on 'show food' by day. ... [more]  

Are you ready to enter that marina? by Captain John Jamieson, Florida
Are you ready to enter that narrow canal or passage ahead that leads into the marina? Have you prepared your boat and crew for the unexpected? No matter if it's a brand new marina or the one you use as 'home base', docking preps will be the same each and every time. ... [more]  

Each summer, in a Canadian cruising tradition, thousands of Western Lake Ontario sailors join the annual summer migration to the Bay of Quinte and the Thousand Islands. ... [more]  

Unlike an automobile, recreational boats have special safety needs when it comes to refueling. Stern drive or inboard powered boats have closed engine compartments where volatile gasoline vapors don’t easily dissipate, and older gasoline powered boats are the riskiest to refuel as their brittle fuel hoses can crack, leaving gas in the bilge after a fill-up. ... [more]  

For the next 72 hours the majority of the World ARC fleet will be moored in Flying Fish Cove on Christmas Island. The crews will have been planning their 48 hours stopover here before leaving Bali so they can make the most of it. Christmas Island is one of the jewels of the Indian Ocean and has a lot to offer. 63% of its land mass is made of National Park which is home to many endemic species. ... [more]  

Three-time President of French Polynesia, Gaston Tong Sang, and current mayor of Bora Bora, has written a strong letter of support for the Blue Planet Odyssey, assuring the fleet a warm Polynesian welcome when they arrive there in 2015. ... [more]  

Remember to properly dispose of obsolete distress beacons by Australian Maritime Safety Authority
You might not be 'down under but here is a cautionary tale!- The Australian Maritime Safety Authority (AMSA) is urging people to ensure they dispose of their obsolete and unwanted distress beacons correctly after emergency services spent more than six hours homing a beacon eventually found dumped in bushland on Queensland's Sunshine Coast over the weekend of 6-7 September. ... [more]  

Blue Planet Odyssey - We made landfall the morning of Saturday, September 13th at 0900 local time as we passed Race Point at the entrance into Cape Cod Bay. Since leaving St John’s less than one week ago we had covered 1109 miles, at an average of just under seven knots. ... [more]  

The World ARC fleet made a great sight on September 14th as they sailed across the start line at the entrance to Benoa Harbour, Bali. Before leaving Bali International Marina, Arsa, a tour guide who had looked after the fleet during their week-long stay, visited yachts to perform a traditional Hindu blessing. It was a beautiful way to send off the fleet and a very special moment for many. ... [more]  

An international team of scientists, including the British Antarctic Survey, studied the geologic history of the area of the Antarctic Peninsula where the Larsen B ice shelf disintegrated, the portion of Antarctica that extends northwards toward South America. The new findings support the idea that such a dramatic collapse can be caused by surface warming. ... [more]  

The Baltic 4 Nations combines a traditional sailing rally with a flotilla holiday, all in the comfort of your own boat. A 370 mile, two week cruise, visiting some of the most beautiful locations in the southern Baltic. Hanseatic cities, quiet fishing harbours, bustling cities, and great beaches, with opportunities to sample local culture and cuisine as well as some great sailing! ... [more]  

Water expands in volume by about nine percent when it freezes, creating a staggering force that can crack a boat engine block, damage fiberglass, split hoses, or destroy a boat’s refrigeration system overnight. ... [more]  

The latest images from Marina Lanzarote show the new marina is looking smart and ready to welcome the yachts for the second Atlantic Odyssey which leaves in November 2014. Gazel Rebel, Blue Jade and Mahe’3, who will all be taking part, have already arrived, with more on the way. ... [more]  

The director of the Phuket Marine Office (PMO), Phuripat Theerakulpisut, yesterday (September 10) gave more details of two shock announcements that have reverberated through the Thai marine leisure industry and among yacht owners in the past few days. ... [more]  

Following on from the success of their Christmas Caribbean Rally (CCR) and Baltic 4 Nations Rally (B4N), Sailing Rallies announce the addition of two new events to their 2015-2016 events schedule: Antigua 2 Falmouth 2015 and the Spanish Rias Rally 2016. ... [more]  

World ARC crews in Bali by World Cruising Club
Today, September 11, 26 World ARC Crews spent the day on a tour to the Kintimani Volcano. Participants were treated to a wide range of cultural, religious and artistic experiences along the way. Benoa harbour is not the most attractive part of Bali so it was a welcome change of scenery, having escaped the morning rush hour, to firstly visit the culturally interesting town of Celuk. ... [more]  

Could your sailing navigation use a tune-up?
Images of marine sunsets by Tripadvisor
Citizen science model proposed to fill fundamental ocean data gap
Ocean Cruising Club celebrates 60th Anniversary with record gatherings
The Boat Cookbook
Indian Ocean-wide tsunami exercise to test readiness
Blue Planet Odyssey - Aventura makes landfall at St John’s
18 anti-piracy weapons for ships to fight pirates
World ARC fleet now arriving in Bali
EU Naval flagship- frigate assist yacht twice maydays in pirate zone
An offer a Galley Guy cannot refuse
World ARC fleet to enter Indian Ocean for the first time
What can you do to prevent electrocution and ESD?
Pack this sailing gear for 'hands-free' lighting
Salty Dawg Rally Seminar Series planned October 8 in Annapolis
Europe tightens up on skippers competency certification
World ARC fleet departs Darwin under full sail
NOAA expedition discovers ship’s timepiece silent for nearly 200 years
Blue Planet Odyssey - Northwest Passage gate opens
A Cruising Guide to the Dominican Republic 6.0 now available
Africa Europe Challenge introduces 'Spectator's Package'   
Niagara-on-the-Lake, a popular cruising destination in Canada   
The crowd-pleasing comforts of catamaran cruising   
'Sailing Stones' of Death Valley seen in action for the first time   
20 coral species listed as threatened under the Endangered Species Act   
A case of crossed wires? A shocking situation!   
OHPRI Teen Summer Camps make a splash   
How amazingly awe-inspiring the Arctic really is   
Boaters urged to attend anchoring meetings next week in Florida   
New atlas provides thorough audit of marine life in the Southern Ocean   
Canal Boating in the Alsace with the Galley Guys   
World ARC fleet arrives in Darwin   
Timeless Tonga - Charter sailing in a Polynesian paradise *Feature   
A fine conclusion to the ARC Baltic 2014   
Where in the world are our strongest corals?   
Incredible efforts to save yacht from being lost at sea   
ARC Baltic fleet visit six countries and six capitals in six weeks   
Helen Island, Palau -a beautiful and unique place   
Barnacle Busting   
From Penguins to Polar Bears   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png http://www.sail-world.com/event_images/image/FaceBook-icon.png  

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL NEW Cru USA
LocalAds   DE  ES  FR  IT