An Oil Spill On My Pond???

Maybe.  Probably not.  How can you tell?  Stick your finger in it (or a stick, if you’re squeamish).

 Bacteria on Turtle Pond East


If it immediately “heals” – that is the shiny film closes back up again – it really IS oil.  If it doesn’t, it’s a naturally occuring bacteria or other natural source.  According to the USGS, these kinds of films “can be found anywhere that ground water, which lacks oxygen and carries iron and manganese, discharges into a stream.”  I assume ponds are likely candidates, too.  The article goes on to say:

Certain bacteria, the oxidizers, fix oxygen onto iron and manganese. Other bacteria, the reducers, remove the oxygen. In fixing or removing oxygen, some are getting energy and others are performing other life functions. Bacteria have been involved in the iron and manganese cycles for billions of years.

So, don’t worry about your pond being polluted until you stick your finger in it!

Learn more:

18 thoughts on “An Oil Spill On My Pond???

  1. I appreciate this post. I’ve seen that in places where I knew it couldn’t be oil, but never knew just what it was. Thanks!

  2. Oh yes, I have had to explain this same thing down here in the swamp. Of course, I then have to explain that the bacteria aren’t “bad” bacteria…
    Thanks for the post!

  3. You know, I was just wondering about this today!
    Now I know–my pool’s safe–for now!

    And I found a Hepatica for you–not as pretty purple as Monarch’s, but my first of the season.
    I’ll share with you.

  4. Glad I could inform a few. It puzzled me for a long time…

    Nina… thanks for sharing!

    Monarch… of COURSE I stuck my finger in it… you know me!

  5. I’m so glad I found this info. So is the bacteria harmful? Is there anything I add to my pond to make it go away? I linked to your site in my post today….

  6. maggie – it is not a harmful bacteria. it occurs naturally when the conditions are right – low oxygen and the presence of iron and manganese… If you don’t like it, i read somewhere (perhaps one of the links above) that you can dredge the pond to remove decaying material. The process of decay uses up the oxygen!

  7. Another Leptothrix discophora lover! I found your blog with my standing Google search for “Leptothrix discophora.” How coincidental that you pointed out yesterday that the process of decay uses the oxygen dissolved in water. In the last two days (honest!) I’ve been puzzling over why I so often see a patch of L.d. right above a leaf in the water. I had gotten as far as thinking that the bacteria responsible for decaying the leaf are doing something that the L.d. likes. I wondered whether the decaying process was liberating carbon that the L.d. was feeding on along with the iron and/or manganese in the water. But maybe your explanation makes simpler sense. I have posted a photograph of L.d. above a leaf in Ohio’s Vermilion River at, should you care to take a look.

  8. I never knew about this – I’ve always wanted to make a pond in our backyard, but with a hydrophilic dog, it just can’t happen (at least not and expect the water and liner to remain very long).

    Thanks for the info!

  9. Pingback: Hello - Manhattan Reefs

  10. Amazing. I just googled “why is there oil in my pond” thinking I’d find some info on these odd little “slicks” that appear from time to time on my pond. And your blog (of which I am already a fan!) comes right up in the second or third spot in my search. I’ll try this test tomorrow on my morning walk. Very useful info! (& I ordered that vernal pool guidebook you recommended and LOVE it, so I’ve been meaning to thank you for that as well).

Leave a Reply to montucky Cancel reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s