Linda Grashoff's Photography Adventures

Walking Downriver in September—1

November 17, 2019

This post might have included 34 photographs, but my better judgement intervened. I still want to show you a lot of what I saw on the annual fall downriver walk that my husband and I take. But I’ll break up the photos into three separate posts, one today, one tomorrow, and one Tuesday. This batch is all about the iridescent evidence I saw of the benign bacterium Leptothrix discophora. As you know if you’ve followed this blog for very long, the iron bacteria, of which L. discophora is one, are obsessions of mine (and the subject of my book They Breath Iron: Artistic and Scientific Encounters with an Ancient Life Form). So here we go again: 19 images of L. discophora films, preceded by an overall photograph of the river as it flows downstream.












12 The orange material you see on the ground beneath the water in this photograph and others is iron oxide, which L.discophora precipitates out of the water.


14 This photograph and the one following show L. discophora‘s film on top of a pudding-like substance that is probably the product of another iron bacterium called Leptothrix ochracea.


16 Notice the iridescence on the leaf- and algae-covered shale in the middle of the photograph. It indicates that the film-covered water recently receded from this area. Click on the photograph to see it larger.



19 This is a crop of the previous photo.

20 And this is a tighter crop. Click on the photograph to see even more detail.

18 responses

  1. Porter, Laurence Marjorie

    Wow! Clicking on that last image for greater detail heightens the magic!

    Thank you for sharing these photos as a triple treat, Linda!


    November 17, 2019 at 2:57 PM

    • Thanks, Larry, and/or Marjorie. Yes, I really want people to see that magic up close.


      November 17, 2019 at 5:03 PM

  2. Do you know what effect a polarizer has on pictures of Leptothrix discophora?


    November 17, 2019 at 3:31 PM

    • It does make a difference, Steve. I leave a circular polarizer on my lens always. But whether it’s as simple as block the light or don’t block the light, I’m not sure. I’m a pretty sloppy photographer. I just turn the polarizer until I get the best image in my view finder without thinking through whether I’m blocking the reflected light.


      November 17, 2019 at 5:10 PM

      • Turning the polarizer until you get the best image in your viewfinder sounds to me like the right approach, given that we want our pictures to look their best.


        November 18, 2019 at 9:55 AM

  3. What a treat for your followers and probably for you as well. Al images are wonderful but #4 is stunning.


    November 17, 2019 at 4:50 PM

    • I’m glad you think these are a treat for my followers, Ken. I thought they might be a self-indulgence. You picked my own favorite in #4.


      November 18, 2019 at 7:57 PM

  4. Wonderful set, Linda! My vote goes to nr9.. 🙂


    November 18, 2019 at 5:24 AM

    • Thanks, Harrie. You may notice that #9 and #4 were taken from the same point, one zoomed out and one zoomed in.


      November 18, 2019 at 8:00 PM

  5. Beautiful pictures, my friend – I particularly like 18. Doing more but shorter posts is a good idea, I think. A 🙂


    November 19, 2019 at 4:04 AM

    • Thank you, Adrian. I agree that shorter and more posts are better, and that’s the way I used to post. But I just couldn’t keep it up and meet other obligations. Perhaps some day I can return to the old schedule.

      Liked by 1 person

      November 19, 2019 at 3:59 PM

  6. It’s good to see the iron bacteria again…some standouts for me are #6, #9, #11, the crops at the end, and tomorrow it might be different. It’s such an interesting phenomenon, and I’m grateful to you for finding it and photographing it so well. 🙂


    November 21, 2019 at 6:47 PM

    • Have you seen any evidence of the iron bacteria in Washington? Theoretically, it’s in all the states, but maybe not near where you live. I’m glad you are enjoying my little obsession. Feel free to change you mind about favorites any time, but I’m especially pleased that you like the more subtle look in #s 6 and 11.

      Liked by 1 person

      November 22, 2019 at 5:15 PM

      • I don’t think I’ve seen it. A mystery. #6 is like a song unfolding on a Japanese scroll, the way the slick flows and the leaves have dropped so gracefully. 🙂


        November 24, 2019 at 2:05 PM

        • “[L]ike a song unfolding on a Japanese scroll”—what a beautiful description, Lynn. Thank you.


          November 24, 2019 at 8:46 PM

  7. I gotta say, I never thought of bacterial pudding as a thing. 🙂 And your pictures show that bacteria can be beautiful as a part of the ecosystem. #4 is also a favorite but #8 is a close second. MMMM…pudding. 🙂


    November 22, 2019 at 5:22 AM

    • Well, I loved butterscotch pudding as a kid. Maybe that’s why pudding comes to mind. Thanks, Steve. (It’s fun to see that different people have different favorites.)


      November 22, 2019 at 5:19 PM

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