How To Find Diatoms

[KurtM]

On my "Catch Of The Day" thread ( viewtopic.php?f=6&t=4581 ) I wrote:

So I'm driving along minding my own business and notice a muddy flat exposed by a low tide. As I have done many times, I stop to take a closer look, and this time see patches of golden brownish greenish looking slime on the surface of the muck. Diatoms!

So here are a couple pictures of what I saw, thought maybe some of you might be interested to see a classic example of diatom slime as it appears in the wild: as a golden-green, or golden-brownish-green, colored slime coating.

I once heard a naturalist describe diatoms and being primarily responsible for the super slippery slime-covered rocks often encountered in rivers and lakes, and that if you've ever busted your fanny while wading, then you probably slipped on diatoms!

This slime may be scrubbed or scraped off of whatever it was found on, or as in this case, skimmed off the top of the mud below. Which means you can actually do a little diatom farming if you like: just place something made of glass or plastic or other smooth material in some water and let it grow a slime coating, then scrub or scrape your slime off and examine it. For diatom cleaning and making permanent slides, see Rod's excellent "Doing Diatoms" thread at:
viewtopic.php?f=10&t=3036

[zzffnn]

Thank you for sharing, Kurt.

I have not seen that much diatom slime at one time/location! The most that I have found was at Galveston's Moody Garden's bay, one a few big slimy rocks (they did look golden brownish).

[billben74]

Cool.
It really is amazing how stuff that to most is mearly slimy, slightly dangerous stuff is quite possibly the source of the greatest beauty on the planet.

[rnabholz]

Cool.
It really is amazing how stuff that to most is mearly slimy, slightly dangerous stuff is quite possibly the source of the greatest beauty on the planet.

Not to mention that Diatoms are estimated to produce somewhere between 20 to 40% of all oxygen on the planet - hard to imagine it could be possible.

Interesting pics Kurt, not much experience with Tidal Flats here.

By way of showing a common diatom hunting ground for my neck of the woods, the long streaming strands visible in this photo are chock a block full of diatoms, and generally produce a very clean sample with minimal minerals - alot of alliteration all of the sudden. ;^)

Claw Target.jpg (230.44 KiB) Viewed 5531 times

[KurtM]

I have not seen that much diatom slime at one time/location!

I know the feeling, that's why there's skid marks on 7th street! Seriously, I wasn't out to collect samples at the time, but when I saw those mats it was like whoa Nellie!! Of course, there's a sample collection kit that lives in my truck - never leave home without it.

I was hoping you might post some of your happy hunting grounds pics, Rod. Here's another couple from me taken last March near Fort McKavett, Texas on the San Saba River near its headwaters, and from which I got a particularly rich harvest.

[Charles]

I drive by bodies of water all the time around here and I always ask myself what samples to take and what I would find in these waters.

I have this theory that the best source for a wide variety of diatoms would be where they float off to die and not what objects to collect while they are alive. My thinking is, diatoms are everywhere in the water. And depending on species, some attach to certain things and others are just floating around. But, when diatoms get eaten by other organisms or just die of old age, every species will all eventually sink to the bottom of the water source. So what better source to get the best variety of diatoms than the bottom of the water source...sand, mud. That's how diatom deposits are formed and then mined. My ideal site would be where water pools and then dig into the mud and sand to get what has already died and sunk into/onto the bottom. That has been the focus of my collecting so far...sand and river bottoms. But those kinds of collections are harder to clean and separate.

[rnabholz]

Hi Charles,

I think your theory is sound, collection from the bottom could provide the full range of forms in a given body.

As you mention, cleaning those samples can be a challenge. Less of an issue for a "picker" like yourself, a nightmare for a strew slinger like me ;^)

A nice sandy sample is manageable, but the fine silt that is often found rivers and streams here can be a real detriment to a pleasing result.

Whatever the method, it is always exciting to gather a new sample and see what you get.