| Abstract: | We studied the taxonomic composition of flagellated nanoplankton in a temperate Canadian fjord, Saanich Inlet, for 1 year using electron microscopy. Most of the species that we identified were from the algal classes Prasinophyceae, Prymnesiophyceae, and Chrysophyceae and the protistan order Choanoflagellida. During summer months, we observed a diverse group of prymnesiophyte, prasinophyte, and chrysophyte species. In fall and winter, the number of species of prasinophyte and prymnesiophyte species in our samples decreased. At times, numerous chrysophyte species were present, and many of these were heterotrophic and typical of freshwater environments, presumably having been carried into the inlet by freshwater runoff. We suggest that during the winter months of 1991 a food web composed of dissolved and particulate organic debris, bacteria, algal cells, and choanoflagellates was an important feature of the plankton. We identified 71 species from 41 genera, and most of these have been reported for either other parts of the world ocean or freshwater environments, indicating that they have widespread distributions. Some species differed in cell and scale morphologies from those documented in the literature, and these distinctions are described. Thirty-two of these species were recorded for the first time from the coastal waters of the northeastern Pacific Ocean. |
