There is a good side to mayflies

They're baaaaack.

Mayflies - an annual but relatively harmless annoyance for residents of the western Lake Erie basin - are out in full force, clinging to street lamps, windows, signs, gas station pumps, and just about any other surface they can find.

People who have lived in this part of the country any length of time generally have learned to put up with the swarms and their fishlike odors by remembering the positive side: Mayflies are sentinels of improving Lake Erie water quality.

Besides, the inconvenience is usually short-term.

Mayflies live only hours after they emerge from Lake Erie. Nature has equipped them with no mouth or stinger. They're harmless, unless they gather in such abundance to make roads slippery.

And, oh, do birds find them yummy.

Mayflies spend their first two years of life as nymphs, burrowing beneath lake sediment and waiting for their wings to sprout. As incredible as their masses seem during the height of a swarm, those which appear on land are but a mere fraction of the total. Most are eaten by fish before they even get out of the lake.

Try telling that to Jim Huff, owner of the Vito's Pizza franchise on Summit Street in Point Place.

"This is a little worse than they've been in recent years," he said, explaining how they were plastered on the side of his building this week. "It's the conversation piece of every person coming in here."

Ditto for the Oregon area, where researchers at the Univer-sity of Toledo's Lake Erie Center along Bay Shore Road have found them so thick in places that they've dimmed the street lights.

"I haven't seen them this thick for a long time," said Kristen DeVanna, a UT doctoral candidate specializing in mayfly research.

There are several reasons why some shoreline communities get slammed with them harder than others.

One of the biggest is the direction of prevailing winds as the insects emerge. One summer about a decade ago, relatively few were found along the Ohio shoreline, but the Ontario side of Lake Erie was smothered in them.

Don W. Schloesser, a research fishery biologist and mayfly expert for the U.S. Geological Survey's Great Lakes Science Center in Ann Arbor, said mayflies on Catawba Island in Ottawa County have just started to emerge. This year's overall hatch, so far, appears to be about average, he said.

John Hageman, manager of the Ohio State University's Stone Laboratory on Gibraltar Island near Put-in-Bay, said mayflies are just now appearing on the Lake Erie islands, one of their usual strongholds.

Although prevailing winds push the ultralight insects in one direction or another, they tend to hatch from west to east in sync with gradual increases in water temperature. Lake Erie is shallowest and, therefore, warmest in the Toledo area.

"We're getting substantial numbers, but not record numbers," Mr. Hageman said. "I don't think they've peaked yet. I think it'll be this week for our area."

Contact Tom Henry at:

thenry@theblade.com

or 419-724-6079.