The Annual Oceanographic Cycle at Igloolik in the Canadian Arctic: II. The Phytoplankton

Abstract

Phytoplankton populations near Igloolik, northern Foxe Basin, began to increase in late April, and reached their climax in mid-August. The rapid late-August decline of the phytoplankton populations coincided with diminishing light. Diatoms were the main biomass producers in Igloolik and the principal food for the marine fauna. The succession of spring Pennatae and summer Centriceae apparently was caused by light and ice conditions. Taxonomic composition of the Igloolik phytoplankton was influenced by the fast ice and by the shallowness and hydrographic uniformity of the adjacent areas. Descriptions are given of two new species of dinoflagellates, Gyrodinium arcticum and Gymnodinium intercalaris, and the new coccolithine flagellate Pontospkaera ditrematolitha.