Pat-a-pat-a-pat-a-pat-a-pat-a-pat-a-pat-a-...

We read about the four signature calls of a common loon. Another sound they make is just as distinctive – when you hear it, you know it’s a loon.

You may remember the sound Fred Flintstone’s feet made as he ran his stone-wheeled car up to travel speed. That’s it: Pat-a-pat-a-pat-a-pat-a-pat-a...And not just a few pat-a’s. Loons have to beat their webbed feet in a long running in order to get airborne.

Loons are adapted best for life on and under water, not on land or in air. They make a living by diving and chasing fish for food, so they have short wings (for streamlining) and less-buoyant bodies than other birds (solid bones instead of hollow, for example). On land, they’re awkward, the feet positioned far back on the body. That’s why they nest right at the water’s edge. In the air they fly fast (some 50 miles per hour), though flight is energy intensive for them – they have to flap every second to stay airborne.

Getting into the air is the real problem. Ducks? Startle them and they leap right off the water, airborne in an instant. Loons need a runway. On a calm day they may need 600 to 700 feet. They need less if able to take off into a wind, and yes, they do aim themselves upwind, without the benefit of the wind sock human pilots use.

So if you’re out on your lake fishing, pier-sitting or kayaking and hear that pat-a-pat-a pat-a-pat-a-pat-a..., you’ll know what it is. Turn toward the sound and watch the show.

All days, all times, all seasons, all weather

When our daughter was a few months old (this was 31 years ago) a wise grandmotherly co-worker advised, “Be sure to take a picture of Sonya crying.” Her larger point was to remember children not just when all smiles on their birthdays but in all times and in all moods. So it is with the lakes we love. To know them is to visit them in all seasons, at all times of day, in all weather.

On this cold, windy, wet, miserable weekend just past, I was tempted to pass Sunday by just sulking in the cabin, waiting for a better day. Instead, after a long late-afternoon walk along the town roads, I took the stairway to our lakefront and stood at the end of the pier. As typical of the whole weekend, grey billowy clouds scudded along on the wind, here and there showing a patch of blue sky. The northwest wind put a forbidding chop on the water. Intermittent rain spotted my glasses. Then it all unfolded.

From over the white pines to the southwest came a bald eagle, then from the north, another. The two soared together for a while. Then one peeled off over the trees and the other sailed along the shoreline, slowly, into the wind, directly over my head, so straight up I had to look down at my feet and catch my bearings, making sure not to lose balance and topple into the water. The eagle made a couple of long, looping circles, then flew off to a perch in a pine off to the east.

Next, as if on cue, an osprey appeared above the trees along our shoreline, wings outstretched, motionless, driven downwind like a kite broken free of its tether, directly over where I stood. Then it looped back into the wind, made a few wide circles over the water, and looped back the way it had come. Over a reef on the lake’s east end, it hung in the air, wings beating steadily, just enough to neutralize the wind. It stayed there for at least a minute, then swung back my way again – yes, directly, absolutely straight overhead. And a few seconds behind it came the eagle again, soaring somewhat higher, closing the space between them until, if armed with a camera, I could have fit both into the viewfinder frame. They parted ways, the osprey east, the eagle west and upward. Both still patrolled the sky as I turned and headed back up the steps.

It’s an object lesson about knowing a lake. Visit it. No matter what. No matter how ugly the weather or your mood. You never know what rewards lie in store. For me, the rush of wind and waves and the rain in my face would have been enough. The eagle and osprey gave me a memory. Who knows what memories your lake waits to give you?

A field guide you’ve probably never seen

Head to a bookstore and you’ll find field guides to just about everything: Birds, trees, mammals, wildflowers, butterflies, fish, reptiles. You may even find field guides for each of these covering just your home state. There’s one you won’t find, though: A field guide to aquatic plants.

Fortunately, even though it’s generally not sold in bookstores or any store, such a guide exists. Through the Looking Glass...A Field Guide to Aquatic Plants, by Susan Borman, Robert Korth and Jo Temte, is a fascinating book. It’s published by the Wisconsin Lakes Partnership doing business as the division of Cooperative Extension of the University of Wisconsin-Extension and the Wisconsin DNR.

I got a copy of this book as part of the admission price for an aquatic plants seminar at a Wisconsin Lakes Convention a couple of years ago. I keep it handy at our home on Birch Lake near Harshaw, Wis., and I’ve been known to refer to it after snorkeling expeditions to help identify a plant I saw.

I’ll let one of the book’s authors explain the beauty of water plants, because he does it far better than I could. Korth says in a brief foreword: “The real magic of aquatic plants can be observed by slipping through the looking glass. In this world beneath the waves, plants unequipped to withstand the force of gravity are buoyed up in a delicate splendor. This underwater forest is a place where dream and reality move side by side.

“As on land, creatures exist at all levels in these aquatic groves. Small fishes soar like birds around the plants. Larger predators lurk in their shadows. Insects, snails, bryozoans, sponges and other curious creatures live out their secret lives in the nooks and crannies of this muted forest. This is a special place moving to an ancient rhythm.”

The book is beautifully and meticulously illustrated: You’ll have no trouble identifying a plant from the detailed drawings. You can find the book on amazon.com and other online sites. If you live on a lake or just happen to love lakes, you’ll find it worthwhile to learn more about the greenery that sprouts along the shorelines, springs from the bottom, and sways with the motion of the waves.

Want to know more about your lake than anyone? It’s easy.

You can live on a lake for years. You can fish it regularly and know the locations of every reef, cabbage weed bed and log pile. You can kayak and canoe and paddle-boat its surface. But you’ll never really know it until you get under the surface.

That’s easy to do with snorkel, swim mask and flippers – about $100 will get you decently outfitted. And if you snorkel, you will in fact know your lake better than anyone else. I say that because in 25 years of vacationing and now living on Birch Lake near Harshaw, Wis., I have never known anyone other than son Todd and me to snorkel here.

Now, maybe that’s because ours is not the greatest lake for snorkeling. The water is passably clear, though a bit cloudy on windy, wavy days like today. Other lakes here in the Northwoods are much clearer and more interesting to explore, with more rock features and shoreline sunken timber. On the other hand, when Todd and I snorkel those other lakes, we still don’t have any competition.

I guess snorkeling is something most people just have little interest in, or something they see as only worth doing on coral reefs in the Caribbean. It’s true of course that in a Northwoods lake you don’t get the Jacques Cousteau experience (although collections of fish I've seen around some cribs and fallen trees have come passably close). Whatever the reason, very few people (and even fewer 60-year-olds like me) look deep into their lakes.

One great thing about snorkeling is the ease with which you can swim when propelled by flippers. As a swimmer I am notorious for lack of stamina. I can’t last doing the crawl for more than a minute or two at a time; I am strictly a side-stroker and elementary back-stroker. But with flippers on I can easily go for an hour at a time. Kicking gently is all it takes. There’s no fatigue, no struggling to stay afloat, and of course no difficulty breathing, because the snorkel tube delivers all the air you want.

What can you learn about your lake as a snorkeler that other people don’t know? Qualitatively, you learn the beauty of the jungles of water plants and the colorful patterns on rocky bottoms, and the feel of waves washing over as you swim. More specifically, you discover fish haunts where you may not have suspected them. You’ll see the abundant and diverse life on the lake bottom – the twisty paths clams make in the mud, the snails, the crayfish (and as for that, my outing today gave lie to the belief among some on my lake that the rusty crayfish problem is coming under control).

As a bonus, you’ll come away with artifacts. For example, on our mantelpiece sits a cream-colored brick engraved LACLEDE KING that I found underwater near our rented cottage. My office shelf holds a coffee mug I fished off the bottom and cleaned up (but do not drink from). Pirate or shipwreck treasure it’s not, but those items wouldn’t be special but for where they came from.

I always enjoy my first canoe trip around the lake in early spring, soon after ice-out, but my first snorkel expedition means more. Once a season isn’t enough, of course. There are whole stretches of shoreline on this 180-acre pool that I haven’t yet explored. I will get to at least a couple of them before this summer is out.

I hope you’ll take time to get to know your lake in this manner. In a way, snorkeling your lake is like breaking through to a new level of intimacy in a friendship or marriage. Life just means more when we look below the surface, when leave our safe zone and go deep.

Three kinds of pads

I used to think all the plants with pads that grew on the water were one and the same species. There were those with big, tough pads, some with yellow blossoms, some with white. Then there were smaller pads, surely just the new and growing stage of the same plant. I thought this way until I attended an aquatic plant seminar at my first Wisconsin Lakes convention three Aprils ago. Then the scales (pads?) fell from my eyes.

It turns out three varieties of water plants with floating pads inhabit Wisconsin waters. The ones with the pure white blooms are water lilies, specifically American white water lilies. They grow long stems that shoot up from this root structures (rhizomes) buried in the bottom. The round leaves (pads) are up to 10 inches in diameter, with a slit that reaches almost all the way to the central stem. The blossoms open early in the morning and close up at about noon.

Unlike most land plants, water lily leaves have their stomata (pores where carbon dioxide enters the plant) on their glossy upper sides. The spongy leaf stalks have four air channels that carry oxygen to the rhizomes (which, by the way, muskrats love eating).

Spatterdock (also called cow lily) has pads similar in size to those of water lilies, and also with a slit, but they are heart-shaped, have wavy (rather than smooth) margins, and tend to be bigger. The stems and leaves grow from buried rhizomes. The real identifier of spatterdock, versus water lily, is the bright-yellow flowers, which when closed up on the ends of their stalks remind me of lollipops on sticks. The flowers aren’t as showy as the lilies – they don’t open up wide the way the white blooms do.  

Watershield (also known as dollar pad or water target) is a much more delicate plant. The pads grow no bigger than about six inches long by three wide. Perhaps most interesting, the stems are a little bit stretchy, so in rough water can bob up and down without breaking off. When the plants are young, the stems and pad undersides are coated with a gelatin-like substance that makes them quite slippery.

How does this plant get is name? Because the pads attach to the stem right  in the middle, giving them a shield-like look. The plants sprout little dark-purple flowers in summer that stand just above the water’s surface. Any fisherman will tell you watershield isn’t as tough as water lily or spatterdock; if a lure gets stuck in watershield, you can usually pull it free before your line snaps. How do I know this? Because fish love to hang out in watershield, and I cast into it if I find it.

So now you know one pad from another. And maybe, unlike me, you’ve known for a long time.

Can't catch this

The late great basketball coach Al McGuire had a vocabulary all his own. He called a close game “white knuckler.” The point when a game’s outcome became clear was “tap city.” An opposing team’s big center was an “aircraft carrier.” And a small, very quick point guard was a “water bug.”

If you live on a lake, you know that last term is apt, because nothing is quicker than a water bug – more specifically a water beetle, or more definitively a whirligig beetle. You’ve certainly seen clusters of these oval, shiny black shapes darting on the surface of still water, making tiny, intersecting V wakes.

As kids we liked to catch things – frogs, crayfish, butterflies, minnows. I can solemnly swear I never caught a whirligig beetle, not even with a scoop net. They are just too fast. These little beetles are rather flat and streamlined for life on the water. They have two sets of compound eyes that let them see both above and below the water (someone ought to design a snorkel mask that gives humans such capability).

They have fairly long forelegs, which they usually hold to the front. The middle and hind legs, shaped like short, flat paddles, provide locomotion (though to see these bugs swim with such smoothness and agility, you’d swear they were somehow jet-powered).

They have chewing mouthparts, and they feed on smaller insects that fall into the water, or on dead plant or animal matter. They can also dive underwater to catch prey. There are about 700 species of whirligig beetles in the world, and more than 50 can be found in the United States and Canada. It doesn’t matter exactly which species you see on your lake. They look and act pretty much alike. Just enjoy the beauty of their frenetic choreography – and don’t even bother trying to catch one.

That all-important DO

We know that fish and other organisms can because of oxygen dissolved in the water. But how does that oxygen get into and stay in the water?

First of all, oxygen doesn’t “dissolve” in water in the same manner as, say, salt or sugar. Salt, for example, is a compound of one sodium and one chlorine atom. In water, it ceases to be a solid, splitting into its two parts – a positively charged sodium ion and a negatively charged chlorine ion. Oxygen gas, on the other hand, consists of two oxygen atoms, and it remains in that form when mixed with water. So instead of referring to dissolved oxygen, should we really speak of suspended oxygen? Or entrained oxygen? (OK, now we are officially splitting hairs.)

Dissolved oxygen (DO) is single most important component of water quality because, quite simply, without adequate DO, next to nothing lives in the water. How does oxygen get into your lake? Mainly from the atmosphere (which contains about 20 percent oxygen) and from photosynthesis – the process by which plants turn sunlight into food. The amount of oxygen in water is tiny compared to the amount in the air. A healthy lake or stream will contain 6 to 8 parts per million (ppm) of oxygen – or 0.0006 to 0.0008 percent. If DO is less than 2 or 3 ppm, most fish will become stressed or die.

So does more of the oxygen in your lake come from plants or from the atmosphere? Well, besides the plants you recognize, like cabbage weed, coontail and water lily, your lake’s water is full of microscopic algae – phytoplankton. The plants and all these tiny algae constantly photosynthesize and produce oxygen while the sun shines. But if that’s the case, then why isn’t a lake with heavy weed growth or in the middle of an algae bloom rich in oxygen? Why in fact can an algae bloom lead to oxygen depletion and fish kills?

Well, remember that photosynthesis requires sunlight – so it doesn’t happen at night or on days with heavy cloud cover. During those times, the plants and algae are consuming food and using up oxygen, just like most other living things. Furthermore, the algae can die off en masse, at which point oxygen-using (aerobic) bacteria break the cells down. That can cause DO to plummet to levels unsafe for fish. Most periods of oxygen stress happen in summer, because warmer water holds less oxygen than colder water, and because oxygen-consuming processes, like decay of dead matter, happen faster at higher temperatures.

So, while algae and plant life contribute to dissolved oxygen, they are a bit of a mixed bag. The main source of life-giving oxygen in your lake is the atmosphere. And the most oxygen mixes in when a healthy wind kicks up waves. So next time you see a wind raising whitecaps out on the water, imagine that your lake has just filled its lungs with a big, deep breath of fresh air. And now the fish can, too.