Resource: Studying the Antarctic Sea Floor

Print Background Essay

The term "benthic" refers to anything associated with or occurring on the bottom of a body of water. The benthic zone is an important component of marine environments. It is where nutrients and decaying organic matter from higher up in the water column eventually settle and get recycled or buried. Benthic ecology is the study of the plants and animals that inhabit these zones. Examples include sea stars, scallops, worms, and sponges. These organisms live on the seafloor or buried within its sediments. Most scavenge for food, feeding only on the dead matter that drifts down from above.

Ecologist Stacy Kim likes doing field research in Antarctica because its seafloor remains relatively undisturbed by human influence and its life largely unrecorded. However, several practical limitations exist. For safety reasons, scuba divers can dive no deeper than 40 meters (130 feet), leaving much of the seafloor off limits to research. Even for shallower dives, the challenges and costs of drilling through the thick ice are significant.

SCINI, the robotic explorer featured in this video, was assembled by engineer Bob Zook to make Dr. Kim's research easier. This remotely operated vehicle allows her and her team to do scientific research in deeper waters and in less accessible areas where risk to a scuba diver may be heightened. The 15-centimeter (5.9-inch) wide SCINI can also fit through a much smaller hole in the ice than a human requires, reducing the time, logistical support, and technical expertise needed to coordinate and complete a dive.

Since its first Antarctic test launch in 2007, SCINI has been remotely guided more than 200 meters (660 feet) below the surface. Dr. Kim and her team have viewed benthic organisms never before seen by humans. Dr. Kim has successfully identified experimental sites sampled in the 1960s by Paul Dayton and John Oliver. These abandoned sites, which have since been colonized by many invertebrate species, offer a unique opportunity to examine benthic life at the individual and community levels.

For example, preliminary analyses of SCINI's images suggest that the growth rate of giant volcano sponges on Antarctica's sea floor is faster during their youth than Dayton had observed in older animals. While the earlier interpretation confirmed a perception of Antarctica as a cold habitat in which biological processes move slowly, this updated analysis suggests that life on its seafloor may recover more quickly than previously believed. This is potentially important because fishing practices that damage the seafloor are occurring more and more in Antarctic waters.

SCINI was developed in response to the needs of scientific research. This technology will, in turn, open up further avenues for scientific research and still newer technology.

To learn more about the maritime life of Antarctica, check out Antarctic Ecosystem and Antarctic Food Web Game.

To learn more about what it's like to do scientific work in Antarctica, check out Antarctica: A Challenging Work Day and Studying Antarctic Seals.

To learn more about undersea exploration technology, check out Sound Waves Underwater: Experiment with Sonar.

Print Questions for Discussion

• How can Antarctic seawater remain liquid at -1.7°C (29°F), that is, below freezing?
• What are some of the research questions that interest Dr. Kim? Can you think of some other questions that might be interesting to explore in undersea research?
• Describe some of the logistical research problems that the submersible SCINI instrument solves.
• What makes the ocean ecosystem under Antarctic ice unique and important to scientists?