Water quality and ecosystem health data used to conduct a cumulative effects assessment of Canadian Great Lakes nearshore waters in support of the Great Lakes Water Quality Agreement are included in this dataset. The data was collected by various government and non-government agencies and organizations and integrated into this dataset to allow the assessment to be conducted. By conducting a regular, systematic assessment of cumulative effects in the nearshore waters of the Great Lakes Environment and Climate Change Canada (ECCC) is able to identify areas of high quality and areas under stress. Knowledge of ecological thresholds, other Great Lakes assessments, stressor information, indicators and local and traditional ecological knowledge will be used to aid in: 1) the identification and mapping of high quality nearshore areas and areas that are or may become subject to high stress and; 2) the determination of factors and cumulative effects that are causing stress or threats. Cumulative effects impacting the nearshore and future threats to areas of high ecological value will be better understood and the knowledge shared will assist in priority setting for science and management at a meaningful and practical spatial scale within each Great Lake and connecting channel.

This dataset contains the Great Lakes Shoreline Ecosystem (GLSE) inventory, which is a geospatial digital inventory of: * ecosite polygon mapping * field survey calibration points * associated ground level ecological data It replaces Great Lakes Shoreline Ecosystem mapping products versions 1.0 and 2.0. It is an update to those products and includes the data and information contained in them but now includes data and information for the entire Canadian side of the Great Lakes shoreline including connecting channels, from the land to water or wetland interface to two kilometers inland. Mapping and ground sampling adheres to the Great Lakes Shoreline Ecosystem classification system, (Lee et. al., in prep.) which is a detailed ecological classification and surveying method.