"Status and trends of phosphorous levels in the offshore waters of the Canadian Great Lakes, 1972 to 2023",,,,, ,,,,, Lake,Phosphorus water quality objective (micrograms of phosphorus per litre),Spring phosphorus level (micrograms of phosphorus per litre),Year of most recent measurement,Status for offshore waters,Long-term trend (1972 to present) Superior,5,2.5,2019,Good,Decreasing [B] Huron,5,2.9,2022,Fair,Decreasing[B] Georgian Bay,5,2.9,2022,Fair,Decreasing[B] Erie: Western basin,12[A],9.5 [D],2023,Poor,Decreasing[D] Erie: Central basin,6[A],14.7,2023,Poor,Decreasing[C] Erie: Eastern basin,6[A],10.5,2023,Poor,Decreasing[C] Ontario,10,5.9,2023,Fair,Decreasing[B] ,,,,, "Note: The classification Good indicates that phosphorus levels in the offshore regions of a lake are close to the lake's objective and it contributes to a healthy food web. The classification Fair indicates phosphorus levels are below a lake's phosphorus objectives and negative impacts to the offshore food web have been observed. The classification Poor indicates phosphorus levels are above a lake's phosphorus objectives. Long-term trends on phosphorus levels in the offshore areas of the lakes since 1972 were calculated using linear regression. [A] Interim phosphorus water quality objectives for Lake Erie basins are based on the recommended binational phosphorus targets: https://www.epa.gov/glwqa/recommended-binational-phosphorus-targets. [B] Decreasing further below the objective. [C] Decreasing over the long-term but still above the objectives.[D] Although the value is slightly lower and below target, there is not enough change in value/limited data in this update for a status change.",,,,, Source: Environment and Climate Change Canada (2024),,,,, Available on the Environmental indicators website (www.canada.ca/environmental-indicators).,,,,,