Just like animals come out of hibernation in the spring, lakes come out of hibernation also.
There has been ice on our lakes all winter, so sunlight has not been able to get through the ice to let plants photosynthesize and produce oxygen, and waves aren’t stirring up the water and mixing in oxygen. The animals that live under the ice are still consuming oxygen all winter long, so when spring comes, they are ready for things to be stirred up. That’s exactly what happens – when water hits 4 degrees Celsius (39.2 degrees Fahrenheit), it is heavy and it sinks, and it stirs up all the nutrients at the bottom of the lake, bringing them to the top so that algae can grow and provide the base of the food chain.
In the Glen Lake/Crystal River Watershed, we have dimictic lakes, which means they mix twice per year. All the nutrients and oxygen get replenished every spring and fall, right when the organisms who live there need them.
Watch this video of Joe Blondia explaining how our lakes turn over twice per year to learn more!