Persistent snow algal fields in spitsbergen: Field observations and a hypothesis about the annual cell circulation

In four expeditions to the northwest coast of Spitsbergen (1995-1998) we ha ve searched for yearly stationary snow algal fields and found them mostly n ear bird colonies on steep snow slopes. In this report, a hypothesis about the redispersion of snow algae on steep snow slopes typical for this coast region is given. Two points are of importance: first, motile cells are rest ricted to a small part of the snowfield near the drop edge on the top, and second, resting cells from previous year deep under the snow play a subordi nate role. Resting cells dispersed onto snowfields located higher in the mo untains are of special importance for next years algal blooming. In the ear ly summer, meltwater streams concentrate cells of these fields in the upper part of the snow slope below the drop edge. Algal proliferation begins her e and locally cell concentration can be very high (about >2 x 10(6) cells m l(-1)) and color the ice clumps deep green. The cell distribution in these wet snow/ice crystals is not uniform. Later in the season as the ground ice is exposed another bloom may form from the previous year's resting cells. Field samples of green, light yellow/red, and orange-rid cells derived from the same location are analyzed by light and transmission electron microsco py.