The Mayfly Mystery

NU researchers study the impact of mayflies on Lake Erie

If you've lived in Western New York for any amount of time, you're probably familiar with the mayfly. These distinctive-looking, large-winged insects, which have a very short lifespan, annually emerge from their nesting places at the bottom of Lake Erie and fly to the nearest waterfront property ... only to die, usually within hours.

Enter Dr. William Edwards, assistant professor of biology at Niagara University. In 2005, he began a research project focusing on oxygen levels in Lake Erie. Part of that research takes into account the mayfly's impact on those levels.

Assisting Edwards with his research is senior Ashley Bantelman, an NU biology major. Together, their work is garnering national attention from environmental publications.

"Back in the 1970s, Lake Erie was referred to as ‘the lake that died,'" said Edwards. "The lake was polluted to such a point that we fertilized it to death."

Far too much fertilizer, or phosphorus, entered the lake during the 1950s, '60s and '70s - from sewage, nearby industry, car washes and even laundry detergent. Algae flourished in the poor conditions, and bacteria would then eat away at the algae, using up the lake's oxygen and killing off just about everything else.

The mayflies started to disappear in the mid-1960s because they couldn't handle the low oxygen conditions in the lake. That caused great concern among environmentalists because the mayfly is an important part of the lake's food chain, a favorite feast of the smallmouth bass, yellow perch and walleye that call the lake their home.

 

Mayflies begin their life underwater, burrowed into lake sediment. Upon hatching, they make their way to the surface and then fly en masse to nearby coastal towns. Swarms can be large enough to appear on Doppler radar.

 

Thanks to enactment of the Clean Water Act in the mid-1970s, Lake Erie began its slow recovery. When large amounts of phosphorus were taken out of the equation, algae growth was slowed and oxygen levels once again returned to normal. And in the 1990s, an old friend, the mayfly, returned.

But then something strange occurred. When the mayflies returned to Lake Erie, the lake's oxygen levels once again started to fall off, which leaves Edwards and Bantelman asking a somewhat surprising question: Do mayflies actually have a role in causing low oxygen levels in Lake Erie?

As it turns out, they probably do. Testing done at NU indicates that the burrows in the bottom of the lake, created by the nesting mayflies, act as a sponge and absorb oxygen from the water. There's also the idea that old pockets of phosphorus are being released due to the burrowing.

To make a long story short, the mayflies may very well be contributing to their own demise.

"The next phase of the study," according to Edwards, "is to look at all the critters who live on the bottom of the lake and create burrows that can cause oxygen to disappear." Bantelman, in a side project, is investigating how other environmental factors impact the way oxygen is pumped into the lake.

"To ignore the situation would mean that lake managers won't be able to make good predictions about lake oxygen levels," Edwards said. "We're interested in providing the managers with useful information."

Edwards is currently looking to secure additional funding for his research through the Great Lakes Restoration Initiative. Should funding become available, he hopes to board a United States Environmental Protection Agency ship and conduct tests in the ship's labs right out on the lake.

After earning her bachelor's degree from NU, Bantelman plans to go on to a grad school where she can continue to study our lakes, and eventually earn her Ph.D.

As the future of the mayfly? That remains to be seen ... and studied.