Conclusions

• Temperature conditions in Toronto Harbour embayments are highly variable with frequent strong temperature gradients that could affect fish growth and well being.
• Upwelling events are the most influential factors in regulating the temperature in Toronto Harbour during the stratified period.
• Water level oscillations are the major driver of water exchange between Lake Ontario and Toronto Harbour, year around.
• Flushing times are between 1 to 11 days which will allow the during the upwelling events periods cold water to penetrate most locations in the Toronto Harbour with a few exceptions, such as Cell 1.
• Inner Harbour seems to be a major driver in amplifying water level oscillations with periods of 1 hour that are propagated in all the connected embayments of the Toronto Harbour system .
• Stratification in the deep areas of the harbour occurs and it is similar throughout the deep area. There is time lag of several hours. However, due to frequent upwellings the time averaged temperatures vary little from the surface to a depth of 6-7 meters.