Environment

Canadian Lakes 'Jellified' by Acid Rain

Decades of acid rain that have made many Canadian freshwater lakes more acidic have also profoundly altered the ecological balance and turned some lake bottoms to jelly.

Even though pollution controls have long since diminished the amount of acid rain, some affected lakes have not recovered from the pollution and have become home to expanding populations of a tiny, slimy crustacean called the Holopedium.

The invertebrate is surrounded by a bulbous coating of jelly.

Swimmers in affected lakes often emerge from the water with the caviar-like balls clinging to their arms and backs.

Writing in the journal Proceedings of the Royal Society B, researchers document that decades of acid rain have flushed away much of the calcium in the lakes, which Holopedium’s biggest competitor, the Daphnia water flea, needs to create an exoskeleton.

With the formerly dominant Daphnia now deprived of enough calcium to bulk up, and gradually disappearing, Holopedium has been able to reproduce unchecked since it needs far less calcium to make its gooey shell.

This competitive edge is creating a jellied mess that threatens to clog water intake systems in the lakes for residential and commercial use.

Top: Microphotograph of the Holopedium. Bottom: Researcher holds a handfull of the small invertebrates, which have slimed some Canadian lakes.