General News · 9th May 2016
The spring blooms in Hague and Gunflint Lakes have been back during the last few weeks, and we are now experiencing the smell and taste in the water of the die-off stage.
After the large 2014 bloom, we collected water samples and identified Volvox algae, dinoflagellates, and diatoms, all non-toxic, but which deplete lake oxygen, and can kill fish and other species. We also observed “blue-green” algae, a cyanobacterium, which is toxic and can cause human health concerns.
The 2015 blooms were noticeable but less extensive than 2014. The bloom this year appears, so far, to be somewhere between those two previous years, serious enough to indicate that we should remain vigilant and active.
The algae blooms respond to many factors, and the two primary factors are warmer spring temperatures and access to nutrients (phosphates and nitrates from human septic and animals). The primary factor we can control, of course, is human septic, and every household in the watershed including ours is a likely contributor. Pumping and restoring septic systems will help. Also, avoid clearing foliage along the lakeshore (since these plants will take up some of the nutrients). Planting along the lakeshore can help. Planting cattails directly in the lake will also help.
I am currently preparing a review of the biological tests that have been ongoing on Hague and Gunflint Lakes, and this report will be completed and available soon from FOCI.
Warmer springs are expected over the next decade due to global warming. We cannot necessarily control this in the short term, but we can upgrade and pump our septic systems, plant any cleared lakeshore, and avoid using phosphate-based soaps. Both stores in Mansons stock non-phosphate soaps. Please use these. Septic upgrade involves personal expense, and we all may face this challenge. It might be a good idea to plan for septic work in your long-range home maintenance. Move outhouses away from the lake edge, or convert to compost toilets or a good septic field.
Locate farm animals far from the lakeside, divert water flow away from animal pens, and construct adequate manure storage.
Avoid inorganic fertilizers, which contain nitrates. Even organic manures can leach nitrates into the water table, so it is best to let manure compost completely before applying.
If all homes in the watershed contribute, we may be able to slow down these annual blooms.
Thank you. Rex Weyler