Author(s): Nadezda D. Romanova
Linked Author(s):
Keywords: No Keywords
Abstract: Samples of freshly frozen and first-year ice were collected in different regions of the White sea. Ice cores of multi-year ice were obtained from the North Pole. Bacterial abundance in freshly frozen ice and in underlying water were similar in winter, while bacterial numbers in the first year ice exceeded that in the water. In early spring bacterial abundance in the underlying water could exceed several times that in the ice. During winter and early spring periods there was no consistent pattern of bacterial distribution in the first-year ice. Maximum bacterial abundance and cell size were generally observed in the ice layers of snow origin. In multi-year arctic ice maximum bacterial abundances were located at 110-125 (middle) and 210-225 cm (bottom) layers, formed during the period of spring and summer bloom. Bacterial abundance in the North Pole ice cores was significantly lower than values obtained by other researchers in the regions of arctic ice formation or outlet from the Transpolar Drift Stream. Data evaluation suggests that bacterial distribution in the first-year ice depends on local spots of available organic matter. This distribution maintains in early spring when bacterial numbers may even decline in the layers of autotrophic community evolvement. In multi-year ice bands of bacteria rich ice may be observed reflecting production peaks in spring-summer period. Still bacterial abundance depends on pack ice migration, as bacterial concentration in underlying water has a strong impact on their concentration in ice brine water.
Year: 2010