Bay of Quinte

Ratna Timsina

IAGLR News report - Rising Nitrate levels in the Great Lakes

The Bay of Quinte (BofQ) was identified as an Area of Concern in the Great Lakes watershed in 1985 as a result of high nutrient levels and severe water quality issues. Ten out of fourteen beneficial use impairments (BUI) were found to be impaired. Since 1985, different remediation activities and mitigation measures have been implemented, including improvements to sewage treatment plants, septic tanks, and industrial sources, which have made significant improvements to the Bay’s water quality. As of today, “excess of nutrients” is the only remaining BUI in the Bay. This study examined the influence of agricultural management practices on nutrient levels in soils and drainage waters at a range of operational farms in the BofQ watershed.

Project members: Catherine Eimers (PI) and Karen Thompson (co-PI), George Archonditsis (UTSC)

Former members: Michael Schmidt (M.Sc. Candidate), Freddy Liu (MSc.), Brandon Lockett (MSc.); Roshelle Chan (MSc.), Anita Chapple (MICA internship), Kayleigh Warriner (MICA internship); Brook Ceci (BSc. Hons); Leroy Reynolds (summer research assistant)

A regional examination of the footprint of agriculture and urban cover on stream water qualityFreshwater systems in cold regions, including the Laurentian Great Lakes, are threatened by both eutrophication and salinization, due to excess nitrog…

Roshelle classified the entire southern Ontario drainage area into different landcover 'clusters', which were correlated with specific water quality typologies. Unsurprisingly, the most heavily tile-drained, cash crop dominated clusters have the highest stream nitrate concentrations, and the most urbanized watersheds have the highest chloride levels. However, the analysis also identified thresholds of landcover, above which exceedances are expected. The clustering analysis allows the objective selection of 'sentinel watersheds' for monitoring (e.g., within each of the major landcover clusters).

Bay of Quinte catchment, with major subwatersheds (sources: Ontario Hydro Boundaries (OHN); Ontario Watershed Boundaries (OWB), Ontario Ministry of Natural Resources and Forestry; National Hydro Network (NHN), Natural Resources Canada).

M.Sc. Roshelle Chan

Roshelle is characterizing changes in land use and land cover (LULC) in southern Ontario since the 1970s and examining the relationship between shifts in LULC and stream water quality over the same period. Her research aims to improve our understanding of how changes in agriculture relate to soil health and nutrient losses.

Tile drainage extent within the Bay of Quinte catchment (sources: Ontario Watershed Boundaries (OWB), Ontario Ministry of Natural Resources and Forestry; National Hydro Network (NHN), Natural Resources Canada); Tile Drainage Area (TDA), Ontario Ministry of Agriculture, Food and Rural Affairs).