Back to News
Projects

Near-Shore Water Sampling Project 2021

Conservation Committee, KBLA
July 1, 2021

Members Involved

  • Ron Pearson
  • Dave Barker
  • Bob Reyburn
  • Donna Reyburn
  • Greig Holder
  • George Lindsay

Purpose

‍This investigation was undertaken following two years of harmful blue-green algal blooms (HABs) on Kahshe Lake to determine whether the historical and ongoing mid-lake, deep water sampling for algal-friendly nutrients like phosphorus and nitrogen carried out in May each year by the District of Muskoka (DMM) and the Environment Ministry (MECP) was providing a representative assessment of nutrient loading associated with shoreline development throughout the open-water season and the potential for future HABs. 

Goal

The main goal of this investigation was to assemble and train a team of volunteers who could carry out the sampling program in a manner that would meet the quality assurance and control required to ensure that the analytical results generated by the analytical laboratory would be comparable to those generated by the DMM and MECP. The goal was driven by the budget allocation of approximately CAD 10K from the KLRA which impacted the scope of the sampling based on the cost of the analytical program.

Outcome

‍The sampling and analysis program demonstrated that the mid-lake, deep-water sampling for algal-friendly nutrients is not providing a representative assessment of the potential for future algal blooms associated with shoreline sources of phosphorus and nitrogen compounds. As such, while the levels of phosphorus and nitrogen compounds detected via the DMM and MECP programs are approximately one-half of those typically associated with HAB development and have shown no upward trend over the past 40 years, this is not the case in near-shore waters where levels of both nutrients increase beyond the May sampling and are up to twice as high as in mid-lake locations. The investigation also demonstrated that the levels of phosphorus in the east end of the lake are well above those in other areas where the DMM and MECP sampling has been carried out. Lastly, the NSWSP demonstrated that the development of HABs in 2021 was associated with shoreline sources of human and animal waste.