By David Czarnecki
I like biology, always have, and always will. I'm especially intrigued by little creatures, mostly those that live in or around water and can only be observed under a microscope. I find almost everything about them interesting. I really don't know why for sure.
I experienced a rather unremarkable suburban childhood, yet one enhanced by summer visits to my grandfather's lake home near Remer. My grandfather was an avid hunter, birder, and angler. He loved his walleyes and lake perch and disdained nearly everything else. Sunfish, largemouth bass, and northern pike, he said, preferred warm "dirty" waters and should be caught (and eaten) only as a last resort. "Avoid the weeds," he would say. "Fish caught there'll taste muddy."
Over the years, however, I found that I caught a lot more fish and got to see a lot more stuff in the waters of the weedy, shallow lake across the road from his clear, cold lake.
Later as an undergraduate at Bemidji State University, I found to my delight that some of my teachers could relate to that same stuff, and they had microscopes to see it up close. During one very cold winter, I saw something in a few drops of water that turned my usual lackluster observations into a solar flare of pure astonishment—a live diatom, a freshwater alga, collected from a depth of about 20 feet of water under 4 feet of ice cover!
How could anything look so healthy under such conditions? I was immediately smitten and have been ever since. Of the million or so drops of water I've examined under a microscope, very few have failed to enlighten and amaze me.
The majority of life forms exist beyond our immediate recognition. The unaided human eye can resolve a dimension as small as about 1/100 inch; and except for just plain size, little else can be interpreted at that scale. Equipped with a decent compound microscope, however, a person can see a dimension 1,000 times smaller. This is the world of algae, bacteria, protozoa, and myriad microinvertebrates—literally the world of cells. To me, this microcosm is at least 1,000 times more interesting.
A few years ago at Itasca State Park, I had the good fortune of encountering a microworld brought to my attention by my youngest daughter, who was swimming at the time.
"Hey, Dad, what's this green, slimy blob stuff floating everywhere in the water?"
A glance through the microscope showed me a colony of slime-producing protozoans known as Ophrydium. Though rarely abundant, Ophrydium is not all that uncommon in northern temperate freshwaters. What I found odd was the large size of some of the colonies—some bigger than a tennis ball—and the diversity of diatoms within the slime.
I collected several of the blobs, so I could identify the diatoms. For the next two summers, I collected and characterized more colonies from area lakes and ponds. Interestingly, I discovered that the diatom inhabitants were associated primarily with their lake or pond, rather than collectively associated with Ophrydium.
I also uncovered two mysteries. First, one of the species of diatoms I encountered, Nitzschia flexoides, was originally described from Lunz Lake in Austria and, to my knowledge, has not been found elsewhere—except Lake Itasca, where it has appeared in every colony I have observed. Second, at the end of the growing season, the colonies break up into individual cells, and the slime disappears; yet I have not encountered N. flexoides in any other of my numerous diatom collections from Lake Itasca. I wonder how and where these diatoms live when the slimy colonies are not around.
Another small wonder I've studied is the "lake ball" of Lake Bemidji. Cladophora aegagropila (more recently classified as Aegagropila linnaei) is a coarse-walled, branching filamentous green alga that forms rocklike aggregates, rolled by wave action along sandy shorelines, much like a scouring pad put in a rock tumbler.
Sponges, mosses, cyanobacteria, cockleburs, chestnuts, and other round forms found along shore may also be called lake balls. But true Cladophora balls, like those of Lake Bemidji, appear to be rare or nonexistent elsewhere in North America.
Yet lake balls are common in parts of Europe and Asia, and usually bigger than the ones in Lake Bemidji, which are less than an inch in diameter. In Japan, where they are called marimo, lake balls have been given Special Natural Monument status and are thus protected. They are also found in Lake Mývatn, Iceland, where they are known as Kúluskítur. Strangely, the lake ball populations found in Lake Bemidji, Japan, and Iceland appear to be the same genetically, but they differ from those of Austria, Estonia, Russia, and Sweden.
How much do we really know about the life that exists around us? How many creatures are out there? What are they doing? How long have they been doing it? Why? I doubt we will ever know for sure. But from my standpoint, one of the most gratifying human experiences is to keep looking.
Does our survival depend on other creatures? If so, which ones? Oops, are we sure? Who's to say, since we don't know what creatures are out there or what they might be doing?
My greatest fear is that two classical branches of biology—natural history and organismal biology—could disappear if the patient, often plodding observation needed for such biology is no longer respected as a worthwhile endeavor.
And yet new discoveries are to be found everywhere, even in places one would least expect to encounter them. For example, a few years ago, a colleague and I did biological inventories of several abandoned mine sites and discovered a diatom that apparently had not been previously described. We named the new diatom Pinnularia (meaning "feather") ferroindulgentissima ("very loving of iron"). It certainly is one tough critter.
So if you want to have some fun, take time to just look around. Get to know your biotic neighbors, large and small. Take an "ology" course, one that lets you see creatures where they live. Then take a peek through a microscope. A whole new universe awaits you.
David Czarnecki died this past May. He was professor of biology and curator of the Freshwater Diatom Culture Collection at Loras College in Dubuque, Iowa, and visiting summer professor at the University of Minnesota's Itasca Biological Station and Laboratories in Itasca State Park.
