1.1 Life On, Under and In...the Ice
Robin Ross, a member of the Palmer LTER team, wrote this personal overview of their research goals, which serves as a general introduction to this set of Activities: students will meet Robin and the LTER team throughout all three 3 videos, and on-line.
"The Palmer LTER (Long-Term Ecological Research) program was established in 1990 to study the polar marine ecosystem in the area west of the Antarctic Peninsula. In the Southern Ocean one of the dominant physical factors structuring the ecosystem is the annual advance and retreat of sea ice, one of the largest physical phenomena in the world's oceans.
The Palmer LTER includes researchers working on many different aspects of this ecosystem, from the growth and movement of sea ice to sea bird reproduction. With my colleague and husband, Langdon Quetin, I am responsible for research on "prey". Prey for the upper level predators like penguins includes large zooplankton (unable to swim against currents) and micronekton (small animals able to swim against some currents). In the Southern Ocean, Antarctic krill is one of the most important prey items. In fact it is a keystone species, the organism upon which many Antarctic predators depend. The analogy is to building an arch with a keystone in the center of the arch which keeps the entire structure from collapsing. Our working hypotheses center on the effects of physical factors (e.g. sea ice and oceanic circulation) on zooplankton and krill distributions, abundances, and "recruitment" within the LTER region. All krill born in one summer belong to that year's "class", similar to the year of a group of students when they graduate from high school. To us recruitment refers to how successful a particular year's class is after their first year of life: a strong year's class is one with many survivors to age 1, and a weak year's class would have few survivors to year 1.
One strong interest is to work with our colleagues to look at the effect of the year-to-year changes we see in zooplankton community composition and abundance (including krill) both up and down the food web, i.e. on the food supply of the krill (primarily phytoplankton), and on their predators (penguins). The concept of broadening the horizons of all aspiring oceanographers and educating them in other aspects of oceanography besides their own specialty was important, and provided an appreciation of other disciplines. As a result we learned to interact knowledgeably with our colleagues, a skill essential to multi-disciplinary teams asking questions about how entire ecosystems function."
The Activities suggested for program 1 simulate:
Near Antarctica, sea ice retreats to four million square kilometers during summer, but grows to cover 19 million kilometers (7,334,000 square miles) during winter. As the air temperature begins dropping in March, the ocean temperature drops to -1.8°C and starts freezing at the incredible rate of 5.75 square kilometers (2.2 square miles) per minute. This thin ice coating covers an area nearly twice the size of the United States. The ice grows to more than a meter thick as winter progresses. Satellite imagery is helpful in monitoring sea ice extent and temperature.
| From The Field | Video Information | Researcher Q
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