Photographs from the recent expedition to Antarctica by a UMass Boston research team immediately stir up memories of the Academy Award winning documentary, March of the Penguins. The purpose of the trip, however, was not to take picture of penguins, but to research ecosystems the area and the impacts that global climate change could have on them.
Understanding the way that Antarctic ecosystems function and how they are affected by outside factors is critical if we want to know how to protect them. The researchers, led by Associate Professor Meng Zhou, studied the temperature, salinity and currents of the waters, as well as the abundance of zooplankton in the water.
Plankton are tiny organisms that live in ocean water and flow with the currents. Phytoplankton remain at the surface of the water and capture sunlight which they turn into useable energy. Zooplankton are slightly larger and feed on phytoplankton. Krill are very small shrimp-like animals and a type of zooplankton. Krill are extremely important to the ecosystem in Antarctica because small animals like fish and penguins feed on krill, as well as large mammals such as seals and even whales.
Since krill are entirely dependant on ocean currents for transportation these also become an important thing to study. Temperature and the amount of salt have impacts on the number of krill in the water as well as the way that the currents move them around. “To understand the circulation patterns and how they transport zooplankton is critical to understand the distribution and survivorship of these birds and mammals.” Said Zhou.
If drastic climate change has impacts on the abundance of krill or the currents that move them, there will be dramatic effects on the entire ecosystem.
The sharp temperature rises from years ago were one of the most striking things discovered on this trip. Zhou has been going on expeditions to Antarctica for 12 years now, and says that it is very noticeably warmer today than just a decade ago. “The most surprising thing to us was how warm it was comparing to my trip in 1992.” Said Zhou, “Many places I went in 1992 were covered by thick ice. Now it was open water.”
Every one or two years researchers from UMass Boston head out on their mission to the far south. There were two trips in 2001, two trips in 2002, one trip in 2004 and one trip in 2006. This year members of the expedition included Di Wu, a PhD candidate; Ryan D. Dorland, PhD candidate; Yiwu Zhu, Research Associate; and Meng Zhou, Associate Professor.
One of the most important discoveries made by the team was of some permanent jets and eddies. These natural features drive the export of nutrients and iron from the Antarctic shelf into the Southern Ocean. This leads to water with large amounts of nutrients and an area conducive to the growth of plankton and krill in a broad region from Elephant Island to South Georgia. This is the reason for the famously high concentration of whales in the region.
The areas that the research team studied include the Southern Drake Passage, which is the body of water between Cape Horn and the Antarctic Peninsula; Bransfield Strait, the narrow strip of water between the Anarctic Peninsula and nearby South Shetland Islands; and the Weddell Sea, which is the large body of water directly to the east of the Antarctic Peninsula that forms a large bay in the continent.
The UMass Boston researchers observed an incredible amount of krill in the Southern Ocean-so abundant that it is harvested for human use. The team encountered Korean and Norwegian krill fishing crews. Their catch is most often used to feed fish stocked in fish farms, but is also occasionally consumed by humans.
Antarctica’s striking beauty is apparent in the research team’s photographs. Zhou hopes his research will help preserve “such a beautiful place.”
Perhaps it is the pristine lack of human interference that makes the far south so awe inspiring. At any rate, human activities may have serious negative effects on the area if steps are not immediately taken to reduce our contributions to global climate change.