Hague and Gunflint Lakes Article by Rex Weyler
Swimmers, fishers, and lakeshore residents have experienced significant algae blooms in both lakes this spring and summer. We have recorded the blooms from above using Om Beach's drone.
Since the historically large algae bloom in Hague and Gunflint lakes, in 2014, Friends of Cortes Island (FOCI) volunteers have been monitoring lake temperature, oxygen levels, nutrient load, and other metrics, with help from the BC Ministry of Environment and Dr. Eric Demers from Vancouver Island University. FOCI has recently published a detailed report on the monitoring program, which is available on the FOCI website.
We have recorded blooms of green algae, blue-green bacteria, and E. coli bacteria in the lake and have been able to trace some bacteria to pets, livestock and human septic in the watershed. Land-use changes, such as lakeshore clearing, roads, and logging can also affect nutrient and bacteria flows. To some extent every household in the watershed is contributing nutrients and bacteria to the water table.
Algae gives off oxygen as it grows, and then depletes oxygen in the lake as it dies, accounting for the unpleasant smell and taste. Repeated blooms can cause a lake to become low in oxygen, and unhealthy for humans and wildlife. All animals, including humans, concentrate nutrients (nitrogen and phosphorous) that feed algal blooms, which have affected hundreds of lakes around the world, such as Lake Erie between Canada and the US, Green Lake in Washington State, and St. Mary and Cusheon Lakes on Saltspring Island.
FOCI collected phosphorus and nitrogen readings from various depths in both lakes in 2014, 2015, 2016, and 2017. Readings were not alarming in the summer months, but in the spring, phosphorus levels in both lakes reached dangerous high-productivity levels, consistent with large spring algae blooms.
This year, the algal blooms have been more extensive than any spring/summer since 2014. Swimmers and lake residents have witnessed "clouds" of green algae in the lakes, and have smelled the unpleasant odor emitted during algae die-off, as lake oxygen is depleted. Some fishers and lakeshore residents have reported fewer trout, including reduced dawn and dusk feeding rise.
We can all do something to help - FOCIís monitoring report provides detailed recommendations for action. To combat the flow of nutrients from the human community, some residents have already examined and upgraded their septic fields and livestock pens, and some have planted cattails or other native plants around disturbed lakeshore, plants that help take up nutrients, bacteria, and toxins. An increase in nutrients that feed algal blooms is extremely common in lakes surrounded by human settlement, and communities around the world have learned certain practices that can reduce the impact. Now is the time to act. If you'd like to help, here are some things you can do:
1. Septic: Inspect, pump, and maintain your septic system
2. Garden with care: avoid nitrogen fertilizers and use all fertilizer and manure sparingly
3. Preserve the shore: Replant disturbed shoreline or leave a strip to go wild
4. Domestic animals: manage livestock and domestic pets to keep manure from the water table
5. Cleaners: Eliminate phosphate soaps and detergents
6. Volunteer: You can help with FOCIís Water Monitoring Project. To volunteer or make a donation, contact Friends of Cortes Island: PO Box 278, Mansonís Landing, BC, V0P 1K0 or contact Helen at: friendsofcortesgmail.com or 935-0087.
See the full Report at the FOCI website
for references and links. You can also visit the FOCI website
to find out more about FOCIís Love the Lakes Stewardship Project, including their new Lake Stewardship Plan .
Coming soon! Thurs 27 July
6pm Mansons Hall Greenpeace Film Screening How to Change the World
, and Lake Fundraiser.Sun 30 Jul
Ė Love the Lakes Day. Join us for an early morning guided paddle. In the afternoon come and make a willow lake critter at Linnaea. Visit FOCI's Facebook page
to find out more.