Mayfly hatch disrupts fishing


I have spent a lot of time in the last month up at Lake Erie doing a lot of fishing. The action has been good with all three species, walleye, largemouth bass, and smallmouth bass but it recently came to almost a standstill for several days. The culprit? The hatch of the mayflies.

First it was the midge hatch a few weeks ago. Clouds of annoying bugs that don’t bite but sure can be a nuisance when you are covered with them by the hundreds. I can deal with them until they get around your eyes and nose and then it can be almost unbearable. Then came the mayflies. Why they are called mayflies is beyond me because the hatch always occurs in June. Now the mayflies don’t necessarily become annoying to you directly, but they sure can make the fishing come to almost a halt as they hatch by the billions.

The life of a mayfly is quite interesting. When we see them as adults, they have already lived for two years at the bottom of the lake. They dig down into the sediment and they filter out organic matter from the dirt. That is how they survive and grow. When we see the adults attached to cars and buildings, they are in the last few days of their life. Those last few days are their reproductive cycle and what is strange, is we won’t see their offspring for two years.

The female will travel back down in the water and lay her hundreds of tiny eggs and this year’s batch won’t be adults until 2025. And if you are curious, you can tell the difference between a male and female mayfly. The females are more yellow and the males are more orangish brown. What’s really unique is that adults are designed to not live very long because they don’t even have mouths. So there is no feeding and of course no biting on humans. They are just annoying.

Even though it can be extremely annoying to clean up the piles of dead carcasses (I am sure you have seen the pictures of the piles of them next to street lights that have been left on) and they can make fishing tough for a few weeks, they are a very good sign that the lake is healthy. Seeing lots of mayflies now tells us that the health of the lake was in a very good place two years ago when the eggs were laid. Not too long ago, in the 60’s and 70’s, there were very few mayflies because Lake Erie was so heavily polluted.

It is also important to realize that they provide a lot of nutrition for lots of wildlife. The newly hatched fish as well as the adults gorge themselves on the adult mayflies as they swim to the surface. The burrowing mayfly youngsters also dig into the lake bottom feeding on algae and they provide a lot of nutrition for perch and walleye. Even the newly hatched young ducks and goslings feed non stop on the adults as they come to the surface providing lots of protein and energy.

So, even though I am not a fan of mayflies because they are such a nuisance and the fishing slows down for a few weeks. I have to remember that not only are they a good sign that the lake is healthy but they also are a great source of food for lots of wildlife.

• The Ohio Division of Wildlife released several digital fishing tools last week that might be of interest to you. The Where to Fish tool equips anglers with a guide on where they are most likely to find the best fishing opportunity based on their interests and criteria. Users can enter the radius in which they are willing to travel, their sport fish species of interest, and their preference of population abundance or size of fish. The tool will filter the user’s selection to identify waterbodies nearby that match their preferences.

The Sport Fish Report tool displays relative abundances (catch per effort) based on a user’s selections of species of interest. Users can identify differences in abundance based on their elections of sport fish species, and whether they search statewide or by a specific location in Ohio.

The Angler Survey tool combines the outcomes of angler surveys for a waterbody and year of interest. Users interested in where anglers go most often to catch fish and how many are caught per hour can use this tool. Each summarized fish species, time spent fishing, the percentage of anglers who fished for that species, and their catch rates are displayed.

If a user is interested in identifying the sport fish in their favorite reservoir, stream, or pool of the Ohio River, they can use the Waterbody Report to select their favorite location and see changes in the sport fish abundance, size, and structure throughout time. In addition, they can view the average length-based growth data by species based on location and year or years of interest.

These tools join ODNR’s Ohio Fish Stocking Records, the most popular dashboard on the DataOhio portal with over 63,000 views. It contains records of fish stocked by the Ohio Department of Natural Resources dating back to 1970. Users can access these records and the new fishing tools by using the keyword “Fish” to search the Data Catalog. The four new dashboards may also be found on the DataOhio Portal’s homepage under “Featured Datasets.” All of these tools can be accessed at the ODNR Division of Wildlife website.

Until next time, Good Hunting and Good Fishing!

Ken Parrott is an Agricultural Science teacher with Northmor High School.

No posts to display