The Chlorophyll Content of Arctic Sea-Ice

A number of observers, working in arctic and antarctic waters, have commented on the discoloration of sea-ice caused by unicellular algae, mainly diatoms, that are frozen into the ice. The discoloration is usually seen when the ice is broken and over turned, because it occurs principally on the lower surface of the ice and occasionally on its sides. The brown or greenish-brown colour is due to the chloroplasts in the algae and undoubtedly indicates the presence of a potential source of food in polar seas in addition to the phytoplankton and the benthic algae. The algae associated with the ice present interesting problems concerning the adaptation of protoplasm to life under conditions of low temperatures (maximum about -1.68°C.) and of the adaptation of photosynthetic activity to low light intensities. Although they have been frequently observed, these algae have been very little studied, partly on account of collecting difficulties. Investigations of algae frozen into sea-ice have been started at the Devon Island station (75° 42'N.) of the Arctic Institute and some preliminary results are reported here. ...