
A report called the "State of the Bay 2018" looks at total phosphorus in eastern and northern Georgian Bay as an important water quality measurement, and it is the first issue to be addressed among key issues confronting the Bay. The report was compiled by the Georgian Bay Biosphere Reserve (GBBR) with support from a steering team that included Georgian Bay Forever. It indicates that the trend for total phosphorus is deteriorating, meaning it is showing change away from acceptable conditions.
Below are links to more information on total phosphorus and how it is impacting the Eastern and Northern Georgian Bay. Hover and click on these topic links to learn more:- “Water Quality: Total Phosphorus” full article from the State of the Bay.
- “Phosphorus Levels in Outer Georgian Bay are Going Down”, article by GBBR’s David Bywater, with partner Severn Sound Environmental Association
- How Georgian Bay Forever (GBF) can help monitor total phosphorous
- State of the Bay Partner Profile: Severn Sound Environmental Association
- Suggested actions everyone can take from the Lake Huron Lakewide Action and Management Plan 2017-2021
Phosphorus Levels in Outer Georgian Bay are Going Down
- Keep a buffer of vegetation along shorelines, which reduces nearshore nutrients.
- Lower your household phosphorus pollution by avoiding detergents and soaps.
- Maintain your septic system properly to avoid leaks and nutrient spills into water.
- Volunteer to monitor water quality by visiting http://www.desc.ca/programs/lpp

Georgian Bay Forever, Water Quality and Phosphorus

- Standardizing Protocols. Georgian Bay Forever (GBF) worked from 2011 to about 2016 to standardize water quality measurements with partners in Eastern Georgian Bay including the Georgian Bay Biosphere Reserve and Severn Sound Environmental Association. For the Township of Georgian Bay, GBF prepared a report that analyzed water quality monitoring in the area and recommended plans for going forward. Within the report is a discussion an Assessment of cyanobacteria dominance in embayments along the Georgian Bay Coastline. Summarized findings showed that “favourable conditions for cyanobacterial growth already exist in these oligotrophic [low nutrient] embayments and mean [average] epilimnetic [above the thermocline and metalimnetic [transition zone in the themocline] total phosphorus concentrations need only rise, say 50% to mesotrophic [moderate nutrient] levels of 12 - 15 μg/L (similar to Sturgeon Bay) from current levels of 8-9 μg/L to generate blooms of nuisance proportions." Given rising Great Lakes water temperatures and increased precipitation (run-off) from climate change, and the presence of iron and anoxia (favourable conditions for bloom formation), the process and responsibilities for monitoring were solidified.
- Read GBF's report to the Township of Georgian Bay
Read the Georgian Bay Biosphere Reserve's report, Enclosed Bays and Inland Lakes Phosphorus Monitoring Guideline 2014
- Supporting research by the University of Toronto's Associate Professor Maria Dittrich in Honey Harbour to help her research measuring the make-up of the sediment, and its capacity to release phosphorous into the water.
- Supporting research that challenges the focus of looking at phosphorus in isolation as a cause in cyanobacteria bloom formation, and reveals the critical role of anoxia and ferrous iron. See the report by Molot and others, York University.
Severn Sound Environmental Association and Phosphorus Monitoring

A combination of remedial actions, such as controlling runoff from farms, as well as stewardship activities, septic upgrades and water-treatment upgrades, combined with ecological changes (such as the introduction of zebra/quagga mussels) have led to significant reductions in total phosphorus and algae growth. The Remedial Action Plan (RAP) targets for total phosphorus of 20 µg/L for Penetanguishene Harbour and 15 µg/L for the rest of Severn Sound continue to be met.
There have been no significant trends in total phosphorus since the mid-1990s, except for a decrease in the inner Penetanguishene Harbour. Although Severn Sound is now considered lower in nutrients, it is important to continue with remedial actions and monitoring, as climate change and invasive species continue to affect water quality in often-unpredictable ways.
What you can do, from the LAMP
5.2.6 ACTIVITIES THAT EVERYONE CAN TAKE
Landowners and the public are encouraged to do their part to prevent nutrient and bacterial pollutants from entering groundwater, streams, lakes, wetlands, and Lake Huron by undertaking the following actions:- Choose phosphate-free detergents, soaps, and cleaners - use appropriate amounts;
- Avoid using lawn fertilizers;
- Always pick up pet waste;
- Use natural processes to manage stormwater runoff and reduce the amount of impervious surfaces;
- Install a rain barrel and plant a rain garden with native plants, shrubs, and trees so that water soaks into the ground;
- Inspect and pump out your septic system regularly;
- Implement improved septic technologies, including conversion of septic systems to municipal or communal sewage systems;
- Incorporate agricultural best management practices, such as grassed swales, filter and/or buffer strips to control and reduce store stormwater runoff; and
- Keep cattle out of streams; leave a buffer strip to trap nutrient and sediment runoff; and plant a shelter belt.