Up from the Bottom

There are visitors to the screens of our lakefront porch this week. A number of mayflies and countless tiny midges cling to the screens and, for that matter, to the siding of the cabin. They’ve come up from the bottom of Birch Lake and up to our place, more than 75 feet back from the water and up a considerable hill.

One thing I know about mayfly hatches is that they don’t help the walleye fishing. But that’s not the main point of interest. Are mayflies hatching on your lake? Maybe you already know their story and where they come from, but in case you don’t, here it is.

Mayflies are insects that belong to the scientific order Ephemeroptera, a name no doubt chosen because these flies are ephemeral. The adults, with their triangular wings that propel them in silent flight in a posture that resembles a man with a jet backpack, live only two nights. They have no functioning mouthparts because they don’t eat – they have no need to. During their brief time in the air above a lake, male and female mayflies mate in swarms. The female deposits eggs as she flies low over the water or dips her abdomen. Some species (there are many) even submerge themselves and lay eggs underwater.

From eggs, mayflies develop into adults through several stages of molting. Different species have different molting stages, which also can vary with temperature and water conditions. The insects in immature stages swim to the surface or grab onto rocks or plants. There, according to the Texas A&M University Agri-LIFE extension website, they molt in minutes or second into winged subimagoes, which fly quickly from the water to nearby plants. There they molt again into adults (imagoes) that fly out over the water to begin the mating cycle anew.

Mayflies are the only group of insects that molt after they have wings, says the Texas A&M website. In all other insect orders, winged forms are found only as adults. A typical mayfly lifecycle lasts one year.

Immature mayfly stages have chewing mouthparts and feed by scavenging small pieces of organic matter, such as plant material or algae that accumulate on rocks or other surfaces. Mayflies require water relatively high in dissolved oxygen, which is why they thrive in fast-flowing trout streams. If your lake has mayflies, that’s one sign (certainly not the only indicator) that it’s in decent condition.  

So how did the mayflies affect the walleye fishing here on Birch Lake? Well, yesterday afternoon I caught two, one of them a 17-inch keeper that I brought back to join another already in the freezer as a fish fry for my wife and me. I put the fish in a landing net and set it on the pier while I moved my boat cover from the pier onto shore. Before I made it back to the net, the walleye flopped free and into the water. There went dinner.

Fishing was deadly slow last evening. Could be the mayflies, could be the east wind that brewed up, could be the Birch Lake gods working their will. Could be plain old angler ineptitude. There are too many variables on which to base a conclusion.

Bass on the Beds

Birds nesting, newborn fawns trying their legs, toads and frogs singing in the swamps.  These are all spring magic, but none greater than fish spawning in the shallows of the lakes. Older brother Steve visited our Birch Lake cabin two weekends ago, and while fishing we spotted smallmouth bass tending round gravelly beds they had cleared of sand and silt so as to lay and hatch their eggs.

Now, anglers sometimes debate whether it’s OK to fish for bass while they’re bedding. I can buy the argument that it’s not altogether sporting. Drop almost anything onto a bed and the bass guarding it is compelled by instinct to pick it up and move it away. So an accurate cast to a bed is almost certain to trigger a strike. And it is in fact a bit too easy.

As to whether fishing for bedded bass harms the population, most of what I read says it doesn’t. If you release the bass where you catch them, they’ll go right back to the nests. And in my lake there are essentially no bluegills or other interlopers to eat the eggs for the few minutes when the resident bass are missing.

So Steve and I prowled along the shoreline looking for light-colored circles in the rocky, gravelly areas, finding them often next to sunken logs. Since I am at the lake much of the time and Steve is a once-or-twice-a-year visitor, I mostly just steered the boat, not fishing the beds myself, satsified just to aid and abet and show my big brother a good time.

Birch Lake holds trophy smallmouths, and Steve caught at least one measuring more than 20 inches – 20 and three-quarters to be precise, just as long as the biggest one I’ve ever caught there. He got one or two that might have crossed the 20-inch threshold but that we didn’t bother to measure. If we had been into the taxidermy thing, Steve would have had himself a trophy for the wall, but we both prefer just to let smallmouths go, in some cases after snapping a picture.

We didn’t overdo it – we stopped after had Steve caught half a dozen bass – all lip-hooked and released unharmed – and had enjoyed one of the better fishing times of his life. By the time I get back to Birch again this weekend, I suspect the spawn will be over, the beds empty, the smallmouths in a resting phase, so that I must focus on walleyes. And that’s fine. If some bass are still on their beds, I may just let them, content to observe. I'm just glad I got to witness the spring ritual of smallmouth bass creating the next generation of their kind.