Last Sunday I awoke to find a few dozen, perhaps maybe 100 mayflies scattered about our Precision 23 sailboat. I am today feeling quite lucky. Lucky that the hatch associated with the below image missed Lake Pepin. The radar image came from down river about 45 miles. Whew! Ducked that mess. I have heard that sometimes the road crews have to bring out their snowplows to clear bridges after mayfly hatches like the one here. The image loop shows the hatch beginning and waning, with the bright green color representing the densest area of the hatch. According to NOAA, the Doppler radar was set on “clear air mode,” which makes thing like dust, pollen and insects visible. The mayflies were hatching from Winona, Mn all the way down river to Guttenberg, Ia. That is approximately 116 miles of swarming mayflies! That would make for a very interesting rendition of “guess how many marbles are in the jar” game. Any guesses, anyone? Any entomologist, sailors out there?
This hatch occurred July 19, starting shortly after 9pm, which almost made it a most unwelcome birthday gift for me. I’m sure the birds and fish got nice and fat on the millions of mayflies though. Not quite as dramatic as a right whale dis-masting a sailboat perhaps, but then we don’t have any whales in the Mississippi River. What we do have is leaping carp, along with many other scourges brought to us by our own hands. At least the mayflies are supposed to be part of the indigenous fauna of our river system.
Image from MN Sea Grant
I wonder what sailing through a blizzard of mayflies would be like? I don’t think I really want to find out.
Click on image for hilarious news report from Sidney Morning Herald.