- Calcium is an essential nutrient vital for physiological and structural processes of living species. Over the past two decades, calcium decline has emerged as a stressor for softwater lakes across North America and Europe.Calcium decline is a legacy of long-term acid deposition and can be further exacerbated by timber harvesting and subsequent forest re-growth. Calcium decline affects aquatic and terrestrial ecosystems; adverse impacts include extirpation of calcium-rich keystone species, dominance of calcium-poor competitors, food web changes, and increased algal blooms. Potential mitigation strategies include catchment-based forest management plans, use of wood ash and lime in forests, application of dust suppressants, and in-stream liming. Each strategy varies in effectiveness, cost, and length of time required for results to be realized.
Due to growing concern among members of the KLCA community, a literature review was conducted in efforts to increase awareness regarding calcium decline in Kawagama Lake in Haliburton, Ontario, and surrounding freshwater lakes in the region. Before selecting a method for mitigation, it is important to understand both the background of calcium decline and the biological interconnectedness between aquatic and terrestrial environments.
This report describes the mechanisms responsible for calcium decline, the ecological effects associated with calcium decline, and possible mitigation efforts that may be used to prevent further decline in lake calcium concentrations.