April 27, 2001
As weather warms in New England and we dream of summer days, a team of Woods Hole Oceanographic Institution (WHOI) scientists has headed south to the frigid waters around Antarctica for the first of a series of international cruises to study the distribution and behavior of krill – the major food source for most animals in the Southern Ocean. The eight-member WHOI team is using a variety of new technologies including a remotely operated vehicle to study the small shrimp-like crustaceans that form the base of the food chain for whales, penguins, seals and other marine life.
The 44-day cruise off Antarctica will be featured in daily reports on National Geographic Society’s (NGS) web site, nationalgeographic.com, starting April 27. WHOI will also offer information on the project at its web site, www.whoi.edu. The web project is the first activity in a new partnership between WHOI and NGS to provide more ocean science news to the general public.
Little is known about how krill survive during the winter months in the Southern Ocean. And while it isn’t the first time shipboard science has been conducted in the austral winter, researchers say the scale and sophistication of the technology being used and the level of collaboration of many organizations makes this program unique.
The research effort is part of a new international program called the Southern Ocean Global Ocean Ecosystems Dynamics experiment (or SO GLOBEC), which is part of a larger U.S. GLOBEC program which studies the potential impact of climate change on marine life. The pilot GLOBEC program was conducted on Georges Bank off the New England coast in the late 1990s and involved many WHOI scientists, ships and equipment.
Two icebreaking research ships operated by the National Science Foundation (NSF), the Laurence M. Gould and Nathaniel B. Palmer, recently departed from Punta Arenas, Chile, as part of a multinational effort that also will include research cruises by vessels from Germany, the United Kingdom, and Korea. The vessels will spend six weeks at sea around the West Antarctica Peninsula and in the Marguerite Bay region, where it is thought the larger animals spend the winter.
Scientists aboard the Gould will conduct detailed studies of the water-column on the continental shelf and in the bay from a series of fixed locations to determine how gyres and other circulation systems and sea ice in the region affect the distribution of krill and other animals. Penguins and seals have been tagged so that they can be tracked by satellite, allowing program scientists to refine their search areas.
At the same time scientists aboard the Palmer, including the WHOI team, will survey the western side of the Antarctic Peninsula centered on Marguerite Bay, one of the region’s most important krill wintering sites, to study the distribution of animals from krill to seals and whales. They will collect krill and other small animals with the Multiple Opening and Closing Net and Environmental Sensing System (MOCNESS), a set of plankton nets of different sizes with environmental sensors to record depth, temperature, and other water conditions. They will also use a specially equipped remotely operated vehicle (ROV) with video imaging systems to study krill and the algae they eat under the ice, and will tow an acoustic sled called BIOMAPER II to study krill, salps and other marine life in the water and under the ice.
The harsh conditions of the Southern Ocean at this time of year will test to the maximum the technological advantages the scientists enjoy, WHOI biologist and expedition participant Peter Wiebe noted. “Just the reality of learning how to carry out research aboard these vessels in ice-covered waters is going to be a tremendous challenge,” he said. Wiebe has been to sea on many cruises in harsh New England waters, but admitted this was a new challenge.
Wiebe said that new technologies to be deployed on the cruise are expected to return a wealth of data previously unattainable. Although high-frequency acoustics is a standard tool to map the distribution of krill, no other existing system has the capability of the Bio-Optical Multi-frequency Acoustical and Physical Environmental Recorder (BIOMAPER-II), a device that the SO GLOBEC researchers will employ. The fiber-optic-based technology will allow the researchers to map the ocean to a depth of 500 meters (1642 feet). “We can actually see simultaneously up and down,” Wiebe said. “This capability is going to give a far deeper reach into the water column. We going to be able see and actually quantitatively assess the abundance of krill at substantial depths.”