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Ocean Research


February 2012 Issue

Sensorbots Deployed in Observation Projects
Sensorbots, a new robotic platform equipped with biogeochemical sensors for monitoring deep ocean processes, have been successfully deployed in deep-ocean projects and will be used with the Monterey Bay Aquarium Research Institute's new undersea cabled environment, the Monterey Accelerated Research System, Arizona State University (ASU) said in December.

Produced by Deirdre Meldrum, senior scientist and director of the Center for Biosignatures Discovery Automation at ASU's Biodesign Institute, the Sensorbots are 4-inch-diameter transparent orbs that have three sensors for measuring pH, temperature or oxygen on their surface. These sensors transmit data to the Sensorbot's inner electronics, which convert the signals into flashes of light that are stored by VentCam, a high-speed camera on the seafloor developed by Tim Crone of Columbia University.

The researchers' goal is to make the next generation of Sensorbots mobile and able to vector in and around hydrothermal vents and cracks in the seafloor. But achieving this is possibly a decade away and depends on battery development, Cody Youngbull, assistant research professor and project lead of the Sensorbot team, told Sea Technology magazine. "In the interim, we expect them to use buoyancy drive technology and current monitors to rise off the seafloor and catch a ride when the current suits them."

Last summer, the Sensorbots were deployed as part of the Regional Scale Nodes project, a cabled underwater observatory in the northeast Pacific Ocean, off the coasts of Oregon, Washington and British Columbia. Part of the National Science Foundation's Ocean Observatories Initiative, this cabled observatory will enable Sensorbots to recharge their batteries and upload their data for immediate transmission via the Internet.

During the most recent research cruise directed by co-chief scientists John Delaney and Deborah Kelley, 20 Sensorbots were positioned on the seafloor at 1,500 meters' depth by Canadian ROV ROPOS. Deployed over hundreds of square meters upon stands that held them above the seafloor, the Sensorbots monitored a hydrothermal vent field in an undersea volcano's caldera for three days. For more information, visit www.mbari.org.

US, Canada Complete Joint Arctic Ocean Survey
The United States and Canada have completed the last mission of their five-year collaboration to collect scientific data on the Arctic Ocean's extended continental shelf (ECS), NOAA announced in December. The data collected will allow the U.S. to determine the exact extent of its sovereign rights in the ECS as set forth in the United Nations Convention on the Law of the Sea.

The six-week mission in August and September employed two flagship icebreakers—the U.S. Coast Guard Healy and the Canadian Coast Guard ship Louis S. St-Laurent. The two-ship approach increased data and saved costs. The 2011 U.S. Arctic mission was led by the Joint Hydrographic Center and the Canadian mission was led by Natural Resources Canada.

Scientists on board Healy used a multibeam echosounder to collect bathymetric data to create three-dimensional images of the seafloor. Scientists aboard Louis S. St-Laurent collected seismic data to determine the thickness of the sediments under the seafloor and to better understand the geology of the Arctic Ocean.

"As in previous Arctic missions, we obtained data in areas we were not entirely sure the ice would allow us to proceed, even with a two-ship operation," said Andy Armstrong, co-chief scientist on the Arctic mission. "This was especially true in the eastern part of the Canada Basin where some of the thickest Arctic ice is found."

Preliminary studies indicate the U.S. ECS, including the Arctic Ocean areas surveyed, total at least 1 million square kilometers, NOAA said. For more information, visit www.noaa.gov.

Scientists Study Microbes Living in Ocean's Crust
A team of researchers from the Integrated Ocean Drilling Program (IODP) Mid-Atlantic Ridge Microbiology Expedition has installed two subseafloor observatories called Circulation Obviation Retrofit Kits (CORKs) to study the role subseafloor microbes play in shaping the Earth's ocean and crust, the National Science Foundation announced in January.

The CORK observatories will allow for active subseafloor experiments over the next five years, with scientists planning to return for the first submersible expedition in early 2012.

Biologists hope to gain a greater understanding how microbial communities affect young ocean crust, whether these communities are unique and where they come from, the National Science Foundation said.

Geography of Gulf Led to Bacteria Consuming Spilled Oil, Researchers Report
The topography of the Gulf of Mexico and its water currents allowed for bacteria blooms to consume most of the deepwater methane plumes after the 2010 Deepwater Horizon oil spill, according to a January report published in Proceedings of the National Academy Sciences.

These findings by University of California at Santa Barbara scientists, with help from University of Rejika, Croatia, engineers, could help answer one of the questions after the spill: How could almost all the gas emitted disappear?

The physical characteristics were based on the U.S. Navy's model of the gulf's ocean currents and on observations of water movements immediately after the spill and for several months after. When hydrocarbon was released from the well, it created bacterial blooms. Instead of being swept out with the ocean currents, those waters circled around over the well repeatedly, consuming more and more hydrocarbon, the scientists said.

The model allowed them test this hypothesis and examine the factors that had been measured, oxygen deficits and microbial community structure.

"We have about a 70 percent success rate of hitting where those oxygen declines were. It means that not only is the physics model doing a good job of moving the water in the right place, but also that the biology and chemistry results are doing a good job, because you need those to get the oxygen declines. It's really a holistic view of what's going on," said scientist David Valentine, one of the study's authors. For more information, visit www.nsf.gov.


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