Ecological Linkages of Nearshore-Pelagic Gradients of Phytoplankton Dynamics in Lake Ontario

Session: 54. - Food Web Ecology and Dynamics of Lake Ontario: Nearshore ? Pelagic Linkages

Mohiuddin Munawar, Fisheries & Oceans Canada, [email protected]
Mark Fitzpatrick, Fisheries & Oceans Canada, [email protected]
Heather Niblock, GLLFAS, DFO, [email protected]
Jennifer Lorimer, Fisheries & Oceans Canada, [email protected]
Robin Rozon, Fisheries & Oceans Canada, [email protected]

Abstract

Phytoplankton communities in coastal and pelagic regions of Lake Ontario have been changing rapidly. The present study explores the linkages between nearshore (0-10m), offshore (10-30m) and pelagic (>30m) zones of Lake Ontario along transects originating at Toronto Harbour in the west and Bay of Quinte in the east and extending out into the deep pelagic waters of Lake Ontario. Phytoplankton biomass was generally low along the western transect (< 1 g m^-3), however the composition changed markedly from phytoflagellates (Cryptophyceae, Chrysophyceae, Dinophyceae) in the nearshore and offshore zones to centric diatoms in the pelagic zone. In contrast, the eastern transect showed a steady decline in the biomass of Cyanophyta from the mid reaches of the Bay of Quinte, through the lower bay and out into Lake Ontario. Despite the observed dilution effect of the lake, Cyanophyta remained a significant part of the biomass at all sites on the eastern transect. This presentation will holistically assess the linkages between nearshore, offshore and pelagic zones of Lake Ontario using a variety of factors including nutrients and primary productivity in addition to phytoplankton biomass and composition.

1. Keyword
algae

2. Keyword
biodiversity

3. Keyword
plankton

4. Additional Keyword
trophic gradients

5. Additional Keyword
primary productivity