Friday, September 28, 2007

USCG Icebreaker Healy Returning from the Arctic

The nation’s largest icebreaker, USCGC HEALY, commanded by CAPT Ted Lindström, returns to her homeport of Seattle, WA on the 30th of September. HEALY’s arrival in Seattle denotes the successful conclusion of the Arctic West Summer 2007 Deployment that began when HEALY departed Seattle on April 3rd. Since April, HEALY has traveled over 25,000 nautical miles and conducted over 2,000 individual science evolutions. The deployment consisted of three missions: year one of the Bering Ecosystem Study, year two of Climate Driven Changes in Impacts of Benthic Predators in the Northern Bering Sea and the third in a series of sea floor mapping expeditions to the Chukchi Cap in the Arctic Ocean. HEALY spent a six weeks between the second and third missions in Seattle conducting scheduled maintenance and training.

HEALY left Dutch Harbor on April 11th to begin the first mission of Arctic West Summer 2007. The Bering Ecosystem Study (BEST) is a multidisciplinary, multiyear project designed to consider all levels of the ecosystem of the Bering Sea, from the chemistry of the water and sediment to the biology of seals and walruses to the social implications of climate change and the roles of people in the system. It is a joint venture funded by the National Oceanographic and Atmospheric Administration (NOAA) and the National Science Foundation (NSF) involving scientists from research institutions around the country. In 2007, the chief scientist was Dr. Raymond Sambrotto of Lamont Doherty Earth Observatory. The BEST project is looking at the changes that take place as the ice edge recedes during the spring. During this time, the sea transitions from a barren, dark, frozen expanse to a sea that is full of light and life in the summer. Very little research has been done in the Bering at this time of year because there are very few research vessels capable of operating in the ice choked waters of the Bering Sea in the spring. HEALY exceeded the expectations of the science party and proved itself to be an excellent platform for BEST, conducting a total of over 400 sampling evolutions at over 200 different stations spread over the central and southern Bering Sea. These evolutions included water measurements taken with a CTD (Conductivity, Temperature, Depth) rosette, sediment samples taken with a mulitcorer and plankton samples taken with a variety of small nets. At seven points during the cruise, parties were deployed to the ice to sample both the ice and the undisturbed water below the ice. The science party left HEALY on May 12th in Dutch Harbor, returning to their home institutions to process the tremendous quantity of data collected over the 32 day cruise. The next BEST cruise is scheduled to be the first mission in HEALY’s 2008 deployment.

After replenishing supplies and loading a new science party, HEALY left Dutch Harbor on May 16th to begin her second mission in support of a National Science Foundation project entitled “Climate Driven Changes in Impacts of Benthic Predators in the Northern Bering Sea.” This project was also multidisciplinary, involving physical oceanography, marine chemistry, marine biology, and the study of biological processes. The cruise took HEALY into the central and northern Bering Sea and was timed to study the ecosystem when the spring explosion of life is being sustained by phytoplankton falling to the seafloor. Chief scientists Jackie Grebmeier and Lee Cooper of the University of Tennessee and Dr. Jim Lovvorn of the University of Wyoming are using several decades of data, some collected aboard HEALY in past years, to assess how food webs and biological communities are structured and changing as water temperatures warm, seasonal ice retreats and predators such as fish and crab find more favorable conditions for growth and range expansions. These changes in the ecosystem need to be understood, as they will likely come at the expense of specialized seafloor feeding birds and mammals, including walruses, spectacled eiders, gray whales and bearded seals. During the cruise, HEALY conducted a total of 1500 sampling evolutions at over 150 different stations. Much of the equipment used was similar to that used during BEST, but this mission also used trawl nets to sample the benthic (or seafloor) animals that live on the bottom of the sea, including sculpins, shrimp, snails and brittle stars. After more than a month of crisscrossing the Bering Sea, HEALY returned to Dutch Harbor and disembarked the science party on June 18th before returning to Seattle for routine maintenance and training. The chief scientists plan to continue to study the changes in the benthic ecosystem in the Bering Sea next year.

HEALY’s third mission during the deployment focused on exploring the relatively uncharted seafloor of the Chukchi Cap. The cruise was sponsored by NOAA’s Office of Coast Survey, in partnership with the University of New Hampshire’s Joint Hydrographic Center. The ship sailed from Seattle to Barrow, Alaska where cruise participants were ferried aboard via helicopter on August 17th. The mission was the third expedition in a series of mapping cruises aboard HEALY that began in 2003, all aimed at mapping the Chukchi Cap area. The science party, led by chief scientists Larry Mayer of UNH and Andy Armstrong of NOAA, continued to explore this poorly known region to better understand its morphology and the potential for including this area within the United States’ extended continental shelf under the United Nations Convention on Law of the Sea (UNCLOS). Several ancillary programs were able to participate in the cruise as well. A team from the National Ice Center was able to deploy a series of ice beacons to help track ice movement in the region and a graduate student from Scripps Institute of Oceanography deployed a series of hydrophones to record the underwater sounds of the Arctic Ocean. Unseasonably light ice cover allowed HEALY to cover over 5,000 nautical miles and reach areas north of 82oN during the four week cruise, dramatically exceeding the science party’s expectations. The primary mapping data, which was collected from HEALY’s multibeam sonar and subbottom profiler, has already revealed some exciting new bottom features. With further analysis, the data will significantly enhance our understanding of the Chukchi Cap and the potential for an extended continental shelf in the region.

An important element of The Arctic West Summer 2007 deployment was involving the local communities in the work being done in their backyards. The BEST science party included a school teacher and a science museum curator who led interaction initiatives for both of the isolated Pribilof Islands. Members of the science party visited the islands to make presentations at the local schools and some members of the local communities were able to visit and tour HEALY as the ship held position off shore. During the second mission, three Alaskan Natives from the St. Lawrence Island villages of Gambell and Savoonga, including a high school student, participated in the cruise, providing valuable local knowledge and expertise. At one point during the cruise a delegation of Coast Guard personnel and scientists visited Little Diomede Island where they worked with the local community to recover some automated sensors installed on an earlier trip. A Native Alaskan from Barrow was included as part of the science party during the third mission. Jimmy Jones Olemaun is a marine mammal observer; in addition to counting seals, walruses and polar bears, he helped HEALY successfully coordinate its work off Barrow with the local community.

HEALY is the newest and largest of the nation’s three heavy icebreakers and the only one with extensive scientific capabilities. The 420-foot cutter was commissioned in 2000 and has a permanent crew of 80. Scientific support is her primary mission, but as a Coast Guard Cutter, HEALY is also a capable platform for supporting other potential missions in the Polar Regions, including logistics, search and rescue, ship escort, environmental protection, and the enforcement of laws and treaties. Many people have begun to speculate what will happen in the Arctic if the less ice leads to more shipping and human activity in the region. When speaking of the future, Admiral Thad Allen, the current Commandant of the Coast Guard, has said that "Icebreakers will have an important role to play." For the time being, HEALY will remain in Seattle conducting scheduled maintenance and training in preparation for her next scientific deployment, which will begin in the late winter of 2008. The deployment being planned for HEALY is similar to the one she just completed. It focuses on studying the consequences of warming trends in the Bering Sea and more survey work in the vicinity of the Chukchi Cap.