Weather Forecast


Fish forage has been abundant

Gerra Gentry holds up a beautiful walleye she landed this past week on Fish Hook Lake. The species has been somewhat persnickety on certain bodies of water recently due to an abundance of natural forage. (Jason Durham / Enterprise)

A few notable transitions have taken place in the aquatic environment over the past week.

First off, spawning for a few different species is either beginning, currently taking place, or finishing up. Largemouth bass, smallmouth bass, sunfish, crappies and rock bass are all in pre-spawn, post-spawn or somewhere in between.

Weather has had a major effect on spawning this season, with unseasonably cold temperatures coupled with high winds late last week, changing to high temperatures are little wind over this past week. That instability not only confuses spawning fish, but equally confuses fish that have finished the reproductive process. Fish can't think about the current weather, they merely react to it.

The final major influence on fish behavior over the past week relates to forage. Spring is a period of regrowth in our lakes and it's not only noteworthy fish species that reproduce. Minnows, insects and amphibians are most abundant in the spring, creating numerous feeding opportunities for all types of fish.

An insect that has hatched on several local lakes this past week are mayflies.

Two bodies of water, Fish Hook and Potato lakes, have experienced a bumper crop of the aquatic insect.

The life cycle of a mayfly varies since there are more than 600 different species in North America.

The common variable, however, is that mayflies hatch in clean water.

Once mayfly eggs hatch, the nymph goes through 20 stages of development. The nymph has a mouth to feed on algae and gills to breathe underwater. The series of developmental stages can take two years or longer. Mayflies ascend to the surface in a sub-adult stage with wings but underdeveloped legs and tail. Once the wings dry, the mayfly takes flight for one purpose; to mate. This takes place in flight and the eggs, up to 8,000 from each female, fall to the water and sink to the bottom to hatch, where the nymphs will live for the next few years, hiding under rocks and burrowed into the silt.

Adult mayflies don't live very long; from about thirty minutes to a couple weeks. Most commonly, mayflies live less than 24 hours. Because the period of existence is so short, adult mayflies don't have a digestive system, since they don't time to feed. Once adult mayflies have finished mating, they perish and fall to the waters' surface where some are eaten by fish.

In other words, mayflies are eaten by fish on their trip from the bottom to the surface and additionally after they've flown through the air and fallen back to the surface.

Walleyes, for instance, love mayflies. Since the state fish commonly feeds near the bottom, it's likely that they gorge themselves on sub-adult mayflies as they make their way to the surface.

After witnessing the thick mats of mayflies covering the water on some of the local lakes, it makes sense that there were a few days of sub-par angling success. However, it shouldn't take long for fish of all species to become active again.