There is no doubt here on the lower river that the mayfly hatch is occurring. This morning we awoke and found our windows covered with the 1 1/2 inch long winged insects.
A little research taught me that this is an annual event. The immature mayflies live in the water feeding on water plants. The hatch occurs to allow reproduction and nothing else. The adult mayflies have no mouth parts so no eating is done. They live from 30 minutes to 1 day and then their life's purpose is fulfilled and they die.
Traffic on the river has been brisk this morning. I've seen the Canadian Olympic and the Maritime Trader and one unidentified Lower Lakes Towing vessel. I was out on a run and didn't have my binoculars.