General News · 12th September 2014
Many people feel that clearing the lake outflow may not help reduce algae/bacteria blooms, so it seems we should not do it until we're sure it matters.
However, the bio-filter sites are going in around the lake where they might help take up bacteria and nutrients from human an animal septic. We still need alder chips for this work.
The bio-filter sites are fairly simple to install. They are essentially a mushroom garden, growing Garden-giant mushrooms that are great to eat.
We are awaiting the lab results for the first round of water sample tests, at which point we will know a lot more about which algae and bacteria inhabit the lake and what the level of nutrients are from the human/animal community.
The principle nutrients that feed algae/bacteria blooms are nitrogen and phosphorus, both of which enter the lake through human and animal septic, and in some cases from grey water (if homes are using phosphate cleaners.)
Anything we can do to reduce these nutrients from flowing into the lake will help reduce the chances of large-scale blooms.
Several residents have mentioned the number dogs around the lake during the summer, and yes, dog scat would contribute nitrogen and phosphorus to the lakes. We will be doing "source" tests eventually, so we'll be able to know precisely which species are contributing bacteria and nutrients to the lake, in which proportion: humans, sheep, dogs, cattle, geese, and so forth.
According to lake biologist Eric Demers at Vancouver Island University, the Cortes community is doing the right thing by monitoring the algae blooms in these lakes and by reducing nutrient flow from human and non-human animal sources. Lakes can appear absolutely fine for years, and then turn suddenly swampy, so monitoring the blooms appears worth the effort.
Thanks to Helmut Burke, who has conducted some water-flow tests. Among the interesting things he discovered: Water flows both ways between the two lakes. In the channel, during his tests, surface water flowed from Hague to Gunflint, while deeper in the channel, the water was flowing "downstream" from Gunflint to Hague. Hague is slightly warmer, so the warmer water appears to flow into Gunflint, where it cools, and returns in a cycle. This is a good thing, for the health of the lakes.
Thanks to David Shipway for the excellent watershed map you see above. The dotted blue line between Gunflint and Sprungman's pond represents a likely underground flow here.
Thanks to everyone who has helped, and for all the good ideas and serious discussion. We have received many fine tips and suggestions.
It will be interesting and informative to see what happens next spring.