Studies by Jon Smol and colleagues at Queens University on lakes in Nova Scotia and Ontario reveal a very worrisome trend – a change in the phytoplankton species associated with declining calcium levels. “Without calcium entering the lakes in run-off, some crustaceans at the base of the aquatic food chain, which make their exoskeletons from the mineral, are at a disadvantage, and they’re being displaced by species that have an jelly-like coating. These jelly-organisms are inedible to many predators, and disruptive to the lakes’ ecological balance.” (CBC report). Acid rain combined with inherently poorly buffered soils, especially in SW Nova Scotia, is the major driver; clearcutting is also cited as a factor. View references on our Water Quality Page.