TEMPORAL VARIATIONS IN THE TAXONOMIC COMPOSITION OF FLAGELLATED NANOPLANKTON IN A TEMPERATE FJORD¹

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.

Nutritional role of protists in the diet of first stage larvae of the Dungeness crab Cancer magister

“…Indeed, Thresher et a1 (1992) concluded that seagrass detritus was the basis of a microbial food web in Tasmanian coastal waters that supported large protists and, ultimately, larval fish. Smith & Hobson (1994) concluded that a food web composed of heterotrophic protists consuming particulate debris, as well as bacterial and algal cells, dominated the winter ecology of a n inlet in the Puget Sound basin. Immediate access to an abundant and predictable source of such nutrition in the waters above the seagrass beds where they hatch may b e important for Cancer magister larvae released during a season of low primary productivity.…”

Scale-bearing nanoflagellates from southern Tasmanian coastal waters, Australia. II. Species of Chrysophyceae (Chrysophyta), Prymnesiophyceae (Haptophyta, excluding Chrysochromulina) and Prasinophyceae (Chlorophyta)

“…Norway (Throndsen 1971, Leadbeater 1972, England (Parke and Dixon 1976), Denmark, Adriatic Sea, Mediterranean Sea, New Zealand (Moestrup 1979, and references therein), southeastern Australia (Beech 1983, Hallegraeff 1983, Baltic Sea (Edler et al 1984, Jochem 1990, Black Sea (Mihnea 1993), Canada (Smith and Hobson 1994), Bering Sea (Konovalova 1995).…”

“…Paraphysomonas butcheri is genetically distinct from three other morphologically similar Paraphysomonas species (Caron et al 1999). (Smith and Hobson 1994), USA (Caron et al 1999), Southern Ocean (Marchant and Scott 2005).…”

“…Italy, England, Adriatic Sea, Algeria, Norway, Denmark (Thomsen 1975, andreferences therein, Tong 1997), Finland (Vørs 1992), Greenland (Vørs 1993), Canada (Smith and Hobson 1994).…”

Temporal variations among planktonic diatom assemblages in a turbulent environment of the southern Strait of Georgia, British Columbia, Canada

“…Smayda 1980), but certain regularities appear when sufficient data from one region, such as the northern European seas (Lange et al 1992). Narragansett Bay (Karentz & Smayda 1984), the Southern California Bight (Reid et al 1985) or Saanich Inlet, a fjord in Vancouver Island, British Columbia (Takahashi et al 1977, Huntley & Hobson 1978, Hobson 1981, 1983, Sancetta & Calvert 1988, Sancetta 1989, Smith & Hobson 1994) have been collected. Saanich Inlet stratifies during late spring and summer months and vertical nutrient fluxes at these times are uncertain (Hobson 1985) sometimes resulting in ap-parent shifts from a diatom-to a flagellate-dominated, METHODS AND MATERIALS flora (Hobson 1983).…”