Sudbury Environmental Study
Long-term Lake Monitoring Programs (MOE)
The MOE conducts various monitoring and research programs at the Co-op Unit. The core monitoring is completed under the umbrella of the Sudbury Environmental Study (SES). The SES program is broken down into two main components: the Intensive and Extensive programs described below.
SES Extensive Program
The SES extensive program began as a 209 lake survey in 1974-1976 and continued in 1981 – 1983 when the total number of lakes surveyed grew to 250. By 1983, the number of lakes for continued surveys was reduced to those with continuing low pH. A criteria of pH 5.5 was chosen as the cut-off and 44 lakes below this threshold were chosen. They have been sampled once per summer every year since. The original goal of the program was to identify the extent of lake acidification in northeastern Ontario. Subsequently, the focus shifted to documenting the responses of lakes to sulphur emission control programs implemented at the Sudbury smelters and at other North American sulphur sources. In recent years, this study has also become important in the study of the interactive effects of acidification and other large scale stressors like climate change, calcium (Ca) declines and UV-B irradiance.
The figure below shows the original 250 lakes and the 44 lakes ultimately chosen for continued monitoring (orange circles). The grey shaded area is the zone of effect around Sudbury, based on Neary’s (1990) sulphate/alkalinity ratios.
The Acidification of Ontario Lakes: An Assessment of Their Sensitivity and Current Status With Respect to Biological Damage. MOE Tech. Rep. Dorset. Neary, B. P.; Dillon, P. J.; Munro, J. R.; Clark, B. J. 1990.
SES Intensive Program
The SES Intensive Program compliments the extensive program (shown previously) by sampling a small number of lakes more frequently and for more parameters. This sampling is typically on a monthly or in some cases bi-monthly basis during the ice-free season (usually six samples from May through October). Samples are taken for the following parameters: biology, (phytoplankton, zooplankton and occasionally benthos), water chemistry, as well as dissolved oxygen/temperature profiles, Secchi disc transparency and colour. The set of lakes contained in the SES Intensive lakeset has increased over the years, and in some cases studies were initiated by different researchers, as interest in these various lakes developed.
The years we began sampling these lakes are indicated by the different colored circles (green = mid 1970s; red = early 1980s; yellow = late 1980s; blue = early 1990s; purple = 2000+).
