General News · 25th June 2014
Christian Gronau and I have continued to monitor the lakes, take samples, and identify the organisms blooming in the lakes. We have learned a bit more, and here is the update:
Although algae are common in a lake, the blooms this spring were extensive and long-lasting. Hague lake was smelly and the water undrinkable, for about 6 weeks in the spring. The bloom died out in Hague as oxygen became depleted, moved into Gunflint during May, and then returned to Hague in June. The second bloom in Hague was smaller, signalling a depleted oxygen state.
As the algae or bacteria die off, they consume oxygen, creating an “anaerobic” or “low-oxygen,” state, harmful to other species. Caleb and Jeramie Summers reported dead trout near their home on Hague in the spring. Trout feeding activity has declined. Normally, each morning and evening the trout can be seen hitting the lake surface for bugs, hundreds of strikes for a good hour. Now, since the spring, these feedings are small and rare. There are still trout in the lake, but their population appears to have suffered during the algae/bacteria blooms.
We have consulted with Rosie Barlak, biologist, Ministry of Environment; Dr. Eric Demers, limnologist (freshwater science), at Vancouver Island University; and Dr. Elaine Ingham, microbiologist at The Rodale Institute, and have learned more about the algae, bacteria, and other organisms.
In the water samples, we found Volvox algae, dinoflagellates, diatoms, and bacteria. We originally thought the primary bloom was Volvox, but it now appears that this bloom was the “blue-green” cyanobacteria, likely Coelosphaerium, according to Dr. Eric Demers. These bacteria can have a toxic effect on other species and can pose human health concerns.
A large bloom of any of these organisms can deplete lake oxygen, and may indicate an advanced state of nutrient loading in the lakes, called “eutrophication.” According to biodivcanada.ca: “Nutrient loading refers to the release, through human activities, of nitrogen, phosphorus, and other nutrients into the environment. Fertilizers from agriculture, phosphates from detergents, and sewage from urban development are examples.”
The biologists have encouraged us to monitor the lakes and take the first and most obvious remedial actions (non-phosphate soaps, septic upgrades, etc. See below.) Both Cortes Market and the Co-op in Mansons carry non-phosphate cleaners and will keep them in stock.
The risks to the lakes and to the community are high. The chances that these lakes would return to a normal ecosystem regime without any community action is extremely small. The lakes appear on a trajectory of increasing eutrophication. Doing nothing and hoping the lakes sort out the nutrient load would be risky.
The biological risks include (1) toxic bacteria blooms fed by the nutrients; (2) oxygen depletion, in which other species (fish, amphibians, plants) suffer or perish, and (3) permanent shift from oxygen-rich freshwater lake that supports fish, to an anaerobic, swamp or marsh regime (low-oxygen condition dominated by decaying algae and bacterial blooms).
The risks to our community include a smelly lake, undrinkable water, loss of tourism appeal, and a decline of property values.
Eutrophication affects thousands of lakes worldwide, turning lakes to swamp conditions. Advanced eutrophication has occurred in lakes throughout Canada, at St. Mary’s Lake on Saltspring Island in BC, on Lake Erie between Canada and the US, at Green Lake in Washington State, in Blue Lake and Fern Ridge Lake in Oregon, Lough Neagh in the UK, and on lakes in China, Africa, South America, and around the world.
Our advisors suggest that the community would be wise to begin remedial actions. There is no single source of these nutrients. They come from phosphate cleaners, nitrate fertilizers, animal manure, and human septic. Even water birds contribute nutrients to the lake. Here are some things that we can do:
• Avoid phosphate cleaners or detergents.
• Eliminate toxic chemicals (paints, varnishes, thinners, waste oils, pesticides) in community drains, which kill the soil organisms that process the nutrients.
• Check Septic systems, maintain, pump, or upgrade as necessary.
• Eliminate out-houses; put in septic or compost the waste.
• Avoid inorganic fertilizers (typically contain nitrates).
• Manage organic manures, which leach nitrates into the water table. Allow manure to compost well before applying on farmland, gardens, or lawns.
• Manage animal waste. Isolate farm animals from the lakeside and water flow. Divert water away from animal pens, and treating any effluent. Build manure storage.
• Conserve water; limit water flow.
• Preserve lakeshore vegetation: replant disturbed lakeside, avoid clearing near lakes.
Clearing the outflow from the lake will also help. We are looking for a crew to help with this job sometime this summer. Let me know (935-0005; rexweyler1gmail) if you’d like to help.
Thank you for reading this. I feel confident that this community can take these simple actions, and help preserve these lakes as freshwater trout lakes.
Friends of Cortes will prepare printed information for the community. Thank you to those who have helped sort out the facts.
Comment by Zoe Miles on 27th June 2014
Thanks for this great update, Rex. A very informative and thorough overview of the situation.
What is involved in clearing lake outflow?
I'd be curious about other ways that islanders other than those bordering the lake can help.
Comment by Richard Trueman on 26th June 2014
Bravo your two, well presented and desperately needed.
I doubt the property value thing though as shameful Victoria is still dumping raw sewage and their beaches have signs warning that swimming on their beaches is dangerous to your health, - and their property values have continued to rise.
I also don’t want to see the last item mentioned, the birds, targeted as a solution or even partial solution. (We need to concentrate on our own s**t.)