Calcium concentrations for lakes sampled as part of the Lake Partner Program for years 2008-12

Your lake’s calcium levels
Email to all C.H.A. Member association Lake Stewards and Lake Reps (President or other rep as listed on your membership form)
·         Please find attached a listing of the calcium reading for Ontario lakes from 2008 to 2012. If your lake participates in the Lake Partner Program your numbers should be included here.
·        C.H.A. Research Director – Terry Moore and I attended a workshop on Calcium levels in our lakes and the impact of forestry practices on them last week in Bracebridge. Speaker was Dr Shaun Watmough – also in attendance and answering questions was Norman Yan who has been leading this charge (he spoke at our C.H.A.  AGM in 2011)
Here is some info that may help you:
1.      If your lake’s level is consistently above 4.5 your lake may be relatively safe
2.      Having said that levels are dropping fairly quickly – Dr Yan estimated they have dropped 10-20% in just in the last few years
3.      I have attached a Calcium fact sheet (Calcium in Ontario Lake)
4.      What happens if Calcium levels drop too far
a.      All living things need calcium
b.      Specifically zooplankton ( at the  base of the food chain)  including daphnia and all fish
c.       If your lake’s population of zooplankton decreases  algae will increase and fish populations will decrease
d.      They have also discovered that low calcium levels  seem to be preventing our lakes from recovering from the decades of acid rain
5.      If your lakes levels are at or below 4.5 you should look at the recommendations in the attached document
6.      More info – you can see Dr Watmough’s presentation at
7.      A study is currently underway to try and calculate the impact of forestry practices on calcium levels – it is due to be presented (not necessarily made public) in the spring
The C.H.A. will continue to follow this critical issue and bring you updates.