Jelly-like zooplankton turns Canadian lakes into clear goo

Some lakes in Ontario have experienced greatly-altered water chemistry in the past decades due to acid rain and human impacts. This acid reacts with calcium in soils surrounding the lakes, reducing the amount of calcium that makes it from the watershed into the lakes.  This is impacting Daphnia, a kind of zooplankton that incorporates calcium into their bodies.  As Daphnia numbers decrease, another species of zooplankton called Holopedium are thriving.  They use much less calcium, and coat themselves in gel to protect themselves from predation. These gooey Holopedium blobs are coating swimmers and could start clogging filtration systems for drinking water. They could also have a large impact on the food chain if fewer animals eat them compared to Daphnia.

http://www.citylab.com/weather/2014/11/acid-rain-has-turned-canadian-lakes-into-a-kind-of-jelly/382922/

Holopedium coating someone's hand after dipping it into a lake.  Photo credit: Ron Ingram/Ontario Ministry of the Environment and Climate Change