The effects of salinity toxicity on species from a sub-arctic zooplankton community, in light of a changing environment

• Main Author: Jones, Brittany K.
• Other Authors: Cottenie, Karl
• Format: Thesis
• Language: English
• Published: University of Guelph 2012
• Subjects: Salinity; Zooplankton; Daphnia; Copepods; Toxicity; Churchill
• Online Access: http://hdl.handle.net/10214/3616

Increasing temperatures are expected to cause secondary salinisation in freshwater systems, such as the zooplankton community of Churchill, Manitoba. Salinity is a key environmental factor structuring these communities, thus, increasing salinity should cause these communities to change; however, previous research has shown that they are resilient. In order to ascertain how changing salinity will affect these communities I conducted toxicity tests for five crustacean species, individually and in a community setting. I sampled several pools throughout the season to ascertain the salinity level at which those same species were most abundant in the field. While the species had significantly different field distributions along the salinity gradient, the salinity levels associated with maximum densities did not correlate with the lab tolerances. However, lab tolerances were outside the field salinity range, thus providing an unexpected result. Local interactions appear to be very important in determining final community composition along this salinity gradient. Northern Scientific Training Program Northern Research Fund