As the warmth of summer envelopes the western shores of Lake Erie and Lake St. Clair, anticipation fills the air for the arrival of mayflies, affectionately known as fish flies. But when exactly will they grace us with their presence, and in what numbers? Let’s delve into the intricacies that govern the timing and abundance of these transient guests.
Getting to Know Mayflies
Mayflies, also called fish flies, are aquatic insects that spend the majority of their lives submerged in water. They endure the winter nestled in the sediment at the bottom of lakes and streams, emerging as adults for a fleeting span of two days to fulfill their reproductive duties before meeting their end.
Factors Influencing Emergence
The emergence of mayflies hinges largely on water temperature. Once the temperature at the water’s depth reaches 20 degrees Celsius (68 degrees Fahrenheit), the mayflies begin their ascent from the depths. In the relatively shallow waters of Lake Erie and Lake St. Clair, surface temperatures closely mirror those below, offering a reliable cue for emergence.
Tracking Water Temperature
Monitoring surface water temperatures is key to predicting mayfly emergence. Buoys equipped with sensors provide real-time data on temperature variations. A few days following the attainment of a 20-degree Celsius surface temperature, the mayflies are poised to emerge.
Tools like the National Oceanic and Atmospheric Administration’s experimental forecast product and the Seagull platform offer invaluable insights into current water temperatures.
Unraveling the Prolonged “Season”
Despite their brief adult lifespan, mayflies grace us with their presence over several months, typically spanning from June to August. This prolonged season is attributed to the staggered emergence of different mayfly cohorts, each adhering to its unique development timeline. Variations in emergence rates among species and environmental conditions further contribute to the extended season.
Forecasting Emergence Numbers
Predicting the exact number of mayflies that will emerge each year presents a challenge due to multifaceted environmental factors.
Survival rates during winter months and oxygen levels in Lake Erie’s depths wield considerable influence over emergence numbers. Harsh winters may diminish survival rates, while oxygen-deprived conditions can impede larval development.
Impact on Land
Not all mayflies that emerge will make landfall, with some finding sanctuary on nearby islands. Wind speed and direction play pivotal roles in determining their destination, whether it be the United States or the Canadian side of Lake Erie. Swarms typically materialize within days of water temperatures hitting 20 degrees Celsius, persisting for up to 10 days.
Final Reflections
While the sight of mayflies may initially overwhelm, it’s essential to acknowledge their role as indicators of water body health. These insects serve as vital sustenance for birds and fish, contributing to the delicate ecological equilibrium of the region’s aquatic ecosystems.
As the mayfly season unfolds, let’s marvel at nature’s spectacle and cherish the invaluable role these creatures play in preserving our local environment.