Wild Notes

By August, a summer of sunshine will have warmed a thin layer at the surface of Lake Superior to a balmy 60 degrees Fahrenheit before the chilly nights of September begin the journey toward ice. When a calm day makes the heat and humidity of the mainland unbearable, a paddle to the sea caves near the Apostle Islands National Lakeshore is in order. Sea kayaks are the most common boat I see on the lake, but a friend recently convinced me that paddleboards are better. First, you can’t swamp them. If you fall off, they don’t fill with water, and you can jump right back on. Second, sometimes falling off and getting back on is exactly the point.

[Which sea caves you visit might be determined by wind direction. The Meyers Beach Sea Caves are open to the northwest. The Roman Point Sea Caves are on the east side of a little peninsula (accessible from a tiny estuary in Lost Creek Bog State Natural Area). Or find your way to another rocky shoreline for a beautiful summer day.

Wild blueberries carpet the sandy hills of the Bayfield Peninsula in the tender light of early morning on the way to the lake. August might be a bit late for a bumper crop, but any blueberries you find along the roadside will be fully ripe…or dried up raisins depending on the year. If you’re able to gather a handful of these sun-warmed treasures, you can imagine you’re taking a dose of magic pills. Their anti-inflammatory pigments, called anthocyanins, have been shown to improve your heart health, vascular function, and gut microbiome. They are basically the elixir of life. I’ll leave after one more handful.

The smell of sulfur bubbles up from the muck as I launch my paddleboard into shallow water. A sand spit protects this estuary and boat landing from the waves of the Big Lake and slows the water of Lost Creek to almost a standstill. The lush marsh plants grow and die quickly. At first, microbes use oxygen to power decomposition in the muck, but when that runs out, decomposition slows down, and the little guys turn to sulfates instead. The fetid smell of hydrogen sulfate means decomposition is slower than growth, and carbon is being stored.

A breeze off Lake Superior quickly dissipates the odor of bacterial activity. The air smells cold. How can that be? We often equate the smell of cold with the absence of smell. Perhaps the clean water gives off no molecules to enter my nasal cavity, dissolve into the mucus, bind to receptors at the tips of neurons, and transmit chemical information to my brain. I inhale deeply.

The bottom drops away as I skim out from the sand spit, but ripple marks in the sandy bottom show that wave action reaches at least as deep as the sunlight. Big waves make big ripples in shallow water, but those same waves will make smaller and smaller ripples as the water deepens. The size of the sand grains also plays a role, with smaller sand grains moving farther with less force. However they form, watching the regular pattern of ripples roll under my board soon has me in a trance.

WHOOP! As I pop back up from a plunge into the icy water, the shock of the cold forces involuntary shouts and laughter from my lungs. No trace of an overheated lethargy remains. My skin, my muscles, and even my soul tingles with life…and the fight-or-flight chemical norepinephrine. Once the initial jolt has passed, I tread water for a minute, enjoying the way the silky lake flows over my sunburned arms. The warmest layer of 60-degree water only extends a few inches, so my toes are colder than my fingertips. Then, with a quick heave, I’m back up on the paddleboard and instantly warm in the sun. It’s much harder to do that with a kayak.

Fully alert, I paddle more briskly, soon coming to an overhanging shelf of sandstone. I run my hand over the rough surface of ripple marks. Unlike the ones I just paddled over, these are cemented together by the pressure of millennia and a thin cement of iron oxide. Just less than a billion years ago, streams broke off pieces of bedrock and carried them into a huge basin. Waves and currents tumbled and washed the rocks until all that remained were the most durable pieces of quartz, and even those had all of their corners worn smooth. Then they settled to the bottom. Waves shaped the ripple marks before they were buried by more sand and pressed into bedrock. Glaciers scraped off the bulk of the overburden, and water is revealing the ripples it sculpted so long ago.

The music of water echoes around me inside the cool shade of a domed cave. Tiny waves bounce and refract off the curved surfaces of rock. Grain by grain, sandstone returns to sand. This shoreline is a duet for the ages.

The giant leg of a sea arch braces against the shore, and as I paddle through the gap, I briefly think about all the rocks that have fallen right there to create the empty space. Recent research conducted in partnership between scientists in the Czech Republic and Ashland, Wisconsin, discovered that as caves and arches are excavated, the residual rock carries more weight and that presses the sand grains more firmly together. What remains gets stronger.

Perhaps wind-twisted red pines whose silhouettes add character to the skyline operate under the same principle. In a forest, trees are sheltered from the full force of the wind by other trees. Ample water and nutrients allow them to grow fast. But braced on the top of a cliff, with roots twisted into crevices, and bearing the brunt of winter storms, the red pines of this shoreline grow slowly. So slowly that their dense, resinous wood can withstand the extremes. What remains gets stronger.

A shadow crosses my board as I turn back toward home. Before I can even look up, a musical croak identifies the shadow as a Common Raven. Ranging across the extremes of the Northern Hemisphere, ravens use a high metabolism to keep them warm in the far north and bare legs to keep them cool in the desert southwest. Their big brains adapt easily to finding food in wildly different habitats.

I like to think that my big human brain is useful for optimizing different habitats, too. When summer gets hot, Lake Superior stays cold. And a paddleboard is the perfect way to both stay out of the water and jump into it.