Description: As part of the Overall Assessment of the State of Nearshore Waters, the nearshore of Lake Ontario, Niagara and St. Lawrence Rivers havebeen delineated into into Regional Units based on physical parameters. Slow changing variables such as depth, substrate, river mouth boundaries, wave energy density and high water conditions were used for delineating the offshore and onshore boundaries of relevant units. The offshore boundary is defined by 30m depth; onshore boundary is the 75.8m contour, defined by a high water mark using historical monthly mean lake levels (1.6m above Chart Datum). Lateral boundaries have been delineated using wave energy density, substrate and shoreline features.Levels of stress (low, moderate, high) have been assigned to four categories and associated measures, and rolled up into an overall cumulative stress for each Regional Unit.This data supports Canadian commitments in the Lakewide Management Annex of the Great Lakes Water Quality Agreement of 2012 to provide an overall assessment of nearshore waters.
Service Item Id: 9670ba07c262465b9e5d45245119c2f5
Copyright Text: Environment and Climate Change Canada (ECCC); integrating data from various sources