Recent growth in Antarctic marine life discovered

From 1901 to 1904, Captain Robert Falcon Scott led his historic first expedition to Antarctica, with the goal of becoming the first to reach the South Pole. Thanks to this 1901 expedition, a present-day team of scientists have over a century’s worth of marine Antarctic seabed data. The international team’s analysis of the data shows recent changes in the growth rate of bryozoans – a class of marine organisms.

According to the paper, published in the journal Current Biology on February 22, 2011:

Scott remains famous for coming second to Amundsen in the race for the South Pole and the fatalities on the journey back to base [all members of Scott’s expedition died, having failed to reach the South Pole first], but scientific effort on his expedition was never sacrificed and set many invaluable physical and biological baselines. Amongst these were collections of benthos, such as the bryozoan Cellarinella nutti, which records environmental information in tree-ring-like growth check lines.

Bryozoans are small, filter-feeding invertebrates that feed on algae. They can be found in many marine ecosystems throughout the world and play a role in the ocean’s biological carbon pump, the process whereby ocean creatures take up dissolved carbon dioxide from surface waters and incorporate the carbon into skeletons and other structures composed of calcium carbonate. Eventually, when the marine life dies and sinks to the bottom of the ocean, the carbon is deposited into marine sediments. These sediments function as carbon sinks.

The research team measured the growth of the bryozoan Cellarinella nutti in Antarctica’s Ross Sea, using both museum and new collections. Historical sediment records from 1901 to 2008 show that growth rates of C. nutti were fairly consistent throughout the early and middle parts of the 20th century, but have nearly doubled over the past two decades. While the cause of increased bryozoan growth is unknown, researchers suspect that it’s due to a corresponding increase in algae production driven by higher wind speeds and nutrient upwelling in the area. The recent higher wind speeds detected in the region may be due to ozone depletion, they suggest.

Although bryozoan growth in the Antarctic is not likely to make a dent in the global carbon cycle any time soon (better to focus on weatherizing your home), these new observations add to the growing body of evidence that important new changes are taking place in polar ecosystems; and highlight the value of long-term ecological research.

Thus Robert Falcon Scott’s expedition – which failed to reach the South Pole first in the early 20th century – is still contributing to the world of science. It has enabled scientists to analyze a century’s worth of marine seabed data from the Antarctic to track and discover recent changes in the growth rate of marine bryozoans, thereby adding to our understanding of changes occurring in this remote part of the world.