mayfly 2016

Photo taken Monday, May 9, 2016

Another sign of spring is in the air, or perhaps evident on your windows, siding or boat lift.  Mayflies are making their appearance, though there have not been reports of a massive hatching. According to Wikipedia they live in fresh water “where their presence indicates a clean, unpolluted environment.”  When they hatch, they emerge from the water fully winged.

John Deming observes that mayflies tend to hatch “when the water temperature is between 62 and 65 degrees and their arrival coincides with the spawning activities of bluegills and bass.”  When last checked yesterday (Monday 5/9), the water temperature was 59 degrees.  A couple of warmer days may encourage more of them to emerge.  When major hatchings take place, you can actually hear them as they pop out of the water.   Swarms of mayflies over Lake Erie have been detected by Doppler radar!

Although Clark Lake experiences major hatchings about this time of  year, they can show up all summer long but their appearance may vary.  They can be lighter in color and of a larger size.

As noted earlier, mayflies are a sign of a healthy lake.  A lot of particulate in the water diminishes their numbers.  While in the water, they breathe through gills and turbidity prevents that from happening.  Further, fewer mayflies may inhibit growth of the fish and bird population as both feed lustily on them.  So if there is a big hatching, that’s good news.  Just don’t breathe through your mouth if you walk into a swarm of them.


Mayflies in 2015