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Environmental Monitoring


August 2014 Issue

Climate Change Affects Indonesian Throughflow
Researchers led by Janet Sprintall of Scripps Institution of Oceanography have found that the flow of water in the Indonesian Throughflow between the Pacific and Indian Oceans—the network of straits that pass Indonesia’s islands—has become more shallow and intense since the late 2000s under the influence of dominant La Niña conditions.

The study, published in Nature Geoscience, suggests that human-caused climate change might make this characteristic more dominant in the throughflow, even when El Niño conditions return. The throughflow has an effect on the climate well beyond its boundaries, playing a role in everything from Indian monsoons to the El Niño phenomena experienced by California. This research starts a new chapter in the history of the throughflow, one characterized by the changed variables created by global warming. Changes in the amount of warm water carried by the throughflow will have a subsequent impact on the sea surface temperature, and so will shift the patterns of rainfall in Asia. The nature of the throughflow influences what nutrients get delivered to organisms in the region and how much.

Thien Nam Buys Ranger 2 to Track ROV in Offshore Oilfield
Thien Nam Positioning JSC (Vung Tau, Vietnam) has recently invested in its first Ranger 2 USBL acoustic positioning system from Sonardyne International Ltd. (Yateley, England), purchased through the company’s regional office in Singapore. Ranger 2 will be used to track an ROV during the installation of a pipe flowline and a gas export pipeline protection mattress in an oilfield offshore Vietnam.

Ranger 2 is designed for tracking underwater targets and positioning DP vessels. The system will use the USBL method to calculate the position of Thien Nam’s ROV by measuring the range and bearing from a vessel-mounted transceiver to an acoustic transponder mounted on the target. Multiple subsea targets can be simultaneously and precisely positioned.

NOAA Issues New Nautical Chart for Delong Mountain Terminal
NOAA has issued a new nautical chart for the Delong Mountain Terminal, a shallow draft port servicing the Red Dog Mine, one of the world’s largest producers of zinc concentrate, on the western coast of Alaska in the Arctic. New chart 16145 fills in historically sparse depth measurements, using new survey data.

“This chart is important to the Arctic economy, providing navigational intelligence for the vessels shipping zinc and lead concentrate from Red Dog Mine and offers vastly more navigational information than the only other available chart of the area,” said RAdm. Gerd Glang, director of NOAA’s Office of Coast Survey.

US Coast Guard Publishes Rule on Inland Navigation Rules
The U.S. Coast Guard has published the final rule finalizing changes to the inland navigation rules and their annexes in 33 Code of Federal Regulations parts 83 through 88. This action aligns the Inland Navigation Rules in the Code of Federal Regulations with the amendments made by the International Maritime Organization to the Convention on the International Regulations for Preventing Collisions at Sea, to which the United States is a signatory. Also, the action incorporates recommendations made by the Navigation Safety Advisory Council.

The changes to the current rules will reduce regulatory burdens by adding more options for vessel lighting, alleviating bell requirements, explaining whistle equipment options and adding more options for navigational equipment. These changes also address the technological advancements of wing-in-ground craft and increase public awareness of the inland navigation requirements by reorganizing and making format changes. The final rule can be found at http://1.usa.gov/1oOmznn.

Eight Companies Receive NOAA Hydrographic Survey Contracts
NOAA has awarded new five-year contracts to eight private hydrographic survey companies for projects throughout U.S. coastal waters. Under the new contracts, which cannot exceed $250 million in total over the five-year period, the companies will provide critical hydrographic data for updating NOAA’s nautical charts.

The firms awarded contracts are: C&C Technologies (Lafayette, Louisiana), David Evans and Associates (Vancouver, Washington), eTrac (San Rafael, California), Fugro Pelagos (San Diego, California), Leidos (Newport, Rhode Island), Ocean Surveys Inc. (Old Saybrook, Connecticut), TerraSond (Palmer, Alaska), and Williamson and Associates (Seattle, Washington).

Cruise Monitors Data on Pacific Plastic Pollution
Captain Charles Moore and his crew of researchers embarked on Algalita Marine Research Institute’s eighth expedition to the North Pacific Central Gyre June 29. This six-week expedition commemorated 15 years of investigating the impact of plastic pollution in the marine environment.

The cruise monitored data needed to make scientific conclusions about the scope and growing effects of plastic marine pollution.

Forecasts Predict Average Dead Zone in Gulf
Scientists are expecting an average, but still large, hypoxic or “dead zone” in the Gulf of Mexico this year, and slightly above-average hypoxia in the Chesapeake Bay.

NOAA-supported modeling is forecasting this year’s Gulf of Mexico hypoxic zone to cover an area of 4,633 to 5,708 square miles.

While close to averages since the late 1990s, these hypoxic zones are many times larger than what research has shown them to be prior to the significant human influences that greatly expanded their sizes and effects.

The models also account for the influence of variable weather and oceanographic conditions, and predict that these can affect the dead zone area by as much as 38 percent.

The forecast for the Chesapeake Bay predicts an early-summer, oxygen-free anoxic zone of 0.51 cubic miles, a midsummer hypoxic zone of 1.97 cubic miles, and a late-summer oxygen-free anoxic area of 0.32 cubic miles.


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