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Environmental Monitoring


May 2011 Issue

Scientists Project Where Japan Tsunami Debris Will Float
Scientists made projections in March of where debris from the tsunami triggered by Japan's 9.0-magnitude earthquake might head. The research was presented in March at the fifth International Marine Debris Conference, which was held in Hawaii.

The debris, which includes items as large as houses and cars, will first spread out eastward from Japan's coast in the North Pacific Subtropical Gyre, according to Nikolai Maximenko and Jan Hafner at the International Pacific Research Center, University of Hawaii at Manoa.

In a year, according to predictions, the Northwestern Hawaiian Islands Marine National Monument will see pieces washing up on its shores; in two years, the remaining Hawaiian islands will see some effects; in three years, the plume will reach the U.S. West Coast, dumping debris on Californian beaches and the beaches of British Columbia, Alaska and Baja California. The debris will then drift into the famous North Pacific Garbage Patch, where it will break into smaller and smaller pieces. In five years, Hawaii's shores can expect to see another barrage of debris that is stronger and longer-lasting than the first one. Much of the debris leaving the North Pacific Garbage Patch ends up on Hawaii's reefs and beaches.

Maximenko developed the model based on the behavior of drifting scientific buoys. His previous work on ocean currents and transports predicted five major regions in the ocean where debris collects if it is not washed up on shores or sinks to the ocean bottom, deteriorates or is ingested by marine organisms. These regions turn out to be "garbage patches."

These model projections will help to guide cleanup and tracking operations, Maximenko and Hafner said. Tracking will be important in determining what happens to different materials in the tsunami debris, for example, how the composition of the debris plume changes with time, and how the winds and currents separate objects drifting at different speeds. For more information, visit www.sciencedaily.com.

Salinity-Measuring Spacecraft On Schedule for June Launch
The Aquarius/SAC-D, an international spacecraft that will take NASA's first space-based measurements of ocean surface salinity, arrived at its launch site April 1 at Vandenberg Air Force Base in California after leaving Sao Jose dos Campos, Brazil, in March. Following final tests, the satellite will be attached to a Delta II rocket for a June 9 launch.

The Aquarius/SAC-D mission, expected to last three years, will provide scientists with a key missing variable in satellite observations of Earth that links ocean circulation, the global balance of freshwater and climate, researchers said.

The mission is a collaboration between NASA and Argentina's space agency, Comisión Nacional de Actividades Espaciales (CONAE). Aquarius, the NASA-built primary instrument on CONAE's SAC-D spacecraft, will map global changes in the concentration of dissolved salt at the ocean surface. For more information, visit www.nasa.gov.

Researchers to Study Environmental Effects Of Shipping Containers Lost at Sea
Each year, an estimated 10,000 shipping containers fall off container ships at sea, many of which eventually sink to the seafloor. What happens to these containers once they reach the deep seafloor is not understood.

A team of researchers from the Monterey Bay Aquarium Research Institute (MBARI) and the Monterey Bay National Marine Sanctuary in March began using a robotic submarine to study the biological impacts of a shipping container resting on the seafloor about 20 kilometers outside Monterey Bay.

MBARI researchers discovered the container at 1,300 meters' depth during a marine biology dive in June 2004. By using the bar code found on the side of the container, MBARI and U.S. Customs were able to link it to the merchant vessel Med Taipei, which had lost 24 containers in a storm earlier that year.

Two years later, the shipping company of the Med Taipei agreed to pay NOAA $3.3 million to settle claims relating to the lost containers. Money from this settlement was used to fund the research dives.

Marine biologists plan to count the number of deep-sea animals on and around the container, and collect sediment samples at various distances from the container for biological and chemical analysis. By comparing animal communities close to and away from the container, the researchers said they hope to determine what effects, if any, the container has had on seafloor life. For more information, visit www.mbari.org.

Statistical Model Helps Detect Shipborne Bioinvaders Before Docking
A team of Smithsonian researchers has developed a statistical model for how to count small, scarce organisms in large volumes of ballast water accurately.

The U.S. Coast Guard has proposed a new set of rules limiting the number of organisms allowed. For larger zooplankton (length, width or height at least 50 microns), the number must be fewer than 10 viable organisms per cubic meter.

Onboard ballast water treatment technologies offer a promising solution, enabling ships to substantially cut the risk of delivering dangerous species, but the challenge of testing the ballast water remains.

The scientists, led by Whitman Miller, a research ecologist at the Smithsonian Environmental Research Center, took samples that exceeded the limit and ran them through various tests to see which violations would be spotted. Larger samples gave the best results: Sampling only 0.1 cubic meter of water made it difficult to detect concentrations even twice as high as the standard. By contrast, when they raised the volume to seven cubic meters, the test regularly picked up violations as low as 13 zooplankton per cubic meter, scientists said.

Another innovation of the model is that it can pool sample results over time and possibly across ships, making it easier to determine if treatment systems function as advertised and thus whether ships are actually compliant, researchers said. For more information, visit www.serc.si.edu.


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