Au Train “Beach Balls”

2018 November 17

We were driving home from Canada on June 27, 2018, and stopped for a bit at Au Train Beach. This is one of the Lake Superior beaches between Munising and Marquette, and is a spot where the bay is capturing a nice bit of sand. This is somewhat atypical for Lake Superior, which is more known for its rocky beaches (the more southerly Great Lakes are the ones with a lot of sand beaches).


Don’t let the sand fool you, though. The beach reverts to rock pretty much as soon as you get beyond the waterline

and once you go down the beach a ways, the sand completely gives way to rock

The sand is here because the shape of Au Train Bay acts as a trap for the waves produced by the prevailing northwest wind, catching particles and debris that blows here from the Keweenaw Peninsula and the North Shore of the lake. What comes here is not just sand, there is also a selection of wood, bark, and other miscellaneous plant parts. This gets macerated by the waves pounding it on the rocks, until it finally washes up here as patches of mangled debris that cover parts of the beach to a considerable depth.


This makes an interesting effect, because some of the debris is elongated twigs and pine needles and shredded wood and such, which the wave action mats together and rolls around on the beach.


This produces surprisingly durable “beach balls”, generally somewhere between the size of a tennis ball and a football.

Once they form, the balls can separate from the main bulk of the debris, and travel around the beach by either wave action or being blown by the wind.


They superficially look like they would be something built by living organisms as a shelter or a nest, but they aren’t. They are more of a hollow mockery of life, as they form and grow and reproduce (by breaking into smaller pieces that then enlarge again) and ultimately “die” when they wash out of the debris field and gradually decompose. I suppose that as they rot, they probably become inhabited by all sorts of little decomposition organisms like springtails and woodlice, but these were so freshly produced that they were mostly devoid of life.

Anyway, they are amusing things to play with when you’ve forgotten to bring any beach toys.

3 Responses
  1. December 3, 2018

    Way cool! Looking at the rocky beach, I wondered if you’d ever considered buying dive booties for strolling about. They make rocks much easier to handle.

  2. December 3, 2018

    Lake Superior is still just barely above freezing in June, so my “dive booties” are my heavy knee-high “Muck Boots” that do an excellent job of keeping the frigid water from touching my skin.

  3. December 10, 2018

    Please type a little louder! I can’t hear you from where I am on Maui!


    (Not really on Maui right now, but certainly some time in the next year.)

Comments are closed.