Getting better pond water samples and specimens

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GeekyWife
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Getting better pond water samples and specimens

#1 Post by GeekyWife » Mon Dec 14, 2020 3:53 pm

I have my compound microscope working very well, and I've figured out the basic techniques to use it effectively. Unfortunately, I am having trouble getting good examples of the biological microworld (in other words, pond life) from the field to a slide.

I live in a rural area a few hundred feet above the nearby small town, with a swale and an intermittment small stream in my back yard, and quite a few large ponds that lie in the leftover pits from abandoned granite quarries. Granite is the dominant rock in the region.

The soil tends to be acid. Moss and ferns are common, and none of the flowing or standing water I've seen has algae in it or mats growing along the shorelines. Instead, moss usually grows on the rocks just above waterline, and then ends abruptly where the water starts. Soil is also nutrient-poor, and growing a garden requires adding nutrients.

I use a jar to take water for sampling, and since there aren't any algal mats, I scrape some of the underwater mud and decaying leaf matter into the jar, and sometimes add some of the moss picked from just above the waterline.

The samples I've taken have shown a few small ciliates, much smaller than a paramecium, and one sample had many live nematodes. Small rod-like organisms that I would guess to be bacteria are also fairly common. An occasional diatom is seen. But there is a very high ratio of water and dead organic material (decaying leaves, etc.) to living matter (no algae, no paramecia, etc.) When I put a drop of water that includes significant amounts of dead leaf matter on a slide, I might find one or two ciliates in the entire drop.

Is there a problem with my sampling technique, or is my soil just very, very poor in the organisms that I'm seeking (large ciliates, rotifers, vorticella, etc.)? What would everyone suggest to find a greater density of more interesting microorganisms?

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75RR
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Re: Getting better pond water samples and specimens

#2 Post by 75RR » Mon Dec 14, 2020 4:17 pm

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You might want to have a look at the moss, apart from water bears you should find a range of animalcules. Soak in water in a Petri dish or similar contraption for a while first.

Use a toothbrush to scrape the rocks that sit in the water that have a brown/yellowish colour film to them, those should be diatoms.

A longer term solution would be to dam the intermittent stream or dig a small pond that it will feed into.
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Plasmid
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Re: Getting better pond water samples and specimens

#3 Post by Plasmid » Mon Dec 14, 2020 4:21 pm

GeekyWife wrote:
Mon Dec 14, 2020 3:53 pm


Is there a problem with my sampling technique, or is my soil just very, very poor in the organisms that I'm seeking (large ciliates, rotifers, vorticella, etc.)? What would everyone suggest to find a greater density of more interesting microorganisms?
My advice from personal experience is to look for as dirty but clear water sources as possible. I had the same problem when I started, getting samples from streams, and lakes yielded very little success, then I found the motherload,( retention runoff ponds). The subdivision where I live has a retention pond for water runoff; the large amount of pollutants from the street and lawns is the perfect breeding ground for Rotifers, amoeba, Stentors, and most of the large ciliates. Another source for me has been the Heatpump AC condensate tray located on the outside of the home, with lots of rotifers.

Greg Howald
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Re: Getting better pond water samples and specimens

#4 Post by Greg Howald » Mon Dec 14, 2020 5:01 pm

Most of the microbes we like to look at don't like acidic water and do not live there in abundance. Basically I find that if a dog will not drink the water it is too acidic for good result. Go ahead and test the ph of the water.
If the water is brown like tea it is probably tannic like a bog. Good luck.
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SWmicro
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Re: Getting better pond water samples and specimens

#5 Post by SWmicro » Mon Dec 14, 2020 8:56 pm

GeekyWife wrote:
Mon Dec 14, 2020 3:53 pm
I am having trouble getting good examples of the biological microworld (in other words, pond life) from the field to a slide.
Hi GW,
Perhaps allow birds to do the collecting for you ?

If the problem is local acidity (or other local depletion problems) and you have birds visiting your garden from further afield then make your own mini-pond; a bird bath with predatator proofed feeding station close by. The birds bring in stuff on their feet etc. Fill the bird bath with rainwater collected on an inert surface [plastic sheet, funnel or bucket preferably old or well rinsed, or rain run-off from your house roof if it has suitable tiles or slates )
Or scooped up recent snow saved into a water tank ( I think you get a fair bit of that in your winters over there ? are you near any industry ? )
Ideally use a limestone or similar carved alkaline rock bird-bath. If not available use an inert container with a limestone rock in it doubling as a perch / grooming area.

This all may may take until the spring to get up to speed. So perhaps a mini-pond aka micro-aquarium. see >
viewtopic.php?f=18&t=7846#p69137
Fill with rainwater or reverse osmosis water (local pet-fish shop ??) not your tap (faucet / local) water. So you can keep it in the warm and perhaps seed it with soil or plants from out of area (holiday visiting ?)

There are ways to make your local water neutral or alkaline but to maintain it that way needs lots of goblydygook terminology around alkaline buffers and water chemistry !

GeekyWife
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Re: Getting better pond water samples and specimens

#6 Post by GeekyWife » Mon Dec 14, 2020 10:32 pm

You've all given me several good ideas to try.

I picked up a sample from the back yard swale this afternoon, from a spot where the water running off from higher up the hill slows down and sits on the soil, spreading out. I'll look at that tonight.

I have a bird feeder up for the winter, so I'll grab some of the wasted shells underneath where their feet fall, add some spring water, and let sit for a while.

We have a sump that prevents water from getting into the basement. I will look at that water, which is ultimately rain or surface water percolated through the soil, and see if there is anything interesting in it.

I collected various moss varieties from different parts of the yard today, and they are soaking in spring water. I'd love to see some tardigrades if I can just find them.

My best rotifer sighting so far was filter-feeding, very interesting to watch. That specimen came from some mildew found in the bathroom!

No industry near here. Rural and quiet, the way I like it.

SWmicro
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Re: Getting better pond water samples and specimens

#7 Post by SWmicro » Mon Dec 14, 2020 11:19 pm

GeekyWife wrote:
Mon Dec 14, 2020 10:32 pm
No industry near here. Rural and quiet, the way I like it.
Me too ! and my wind (and rain!) is straight off the Atlantic :)

Good plans, good luck.
The only caveats I would raise is with your "spring water"(*1) and your "ultimately rain or surface water percolated through the soil"(*2) in order to investigate what others have said about the acidity problem.

(1) If it is from a local spring it is likely as acidic as your local ponds if it is a shallow spring, or low hardness if it is from a deep well or bore hole in your area and liable to become as acidic as your local ponds when you add your local soil (we are back to buffers)
If it is commercial bottled "spring water" all bets are off.

(2)when rain water percolates through your local soil it will become similar to your local ponds. The rain (or snow) needs to be collected au naturel and then added to a non-acidic substrate/soil or other inoculum.

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micro
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Re: Getting better pond water samples and specimens

#8 Post by micro » Mon Dec 14, 2020 11:39 pm

If you can find a pond with fish in it that will be good, fish means there's an ecosystem and a pond = still water. Streams don't have much to look at because the flowing stream stops microbes from congregating there. They get pushed farther down till the stream ends.

GeekyWife
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Re: Getting better pond water samples and specimens

#9 Post by GeekyWife » Wed Dec 30, 2020 3:10 pm

There are some fishing lakes here, but not too close to me, and this time of year everything is frozen. I will probably have to wait until spring to get water samples from lakes with fish.

GeekyWife
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Re: Getting better pond water samples and specimens

#10 Post by GeekyWife » Wed Dec 30, 2020 3:12 pm

SWmicro wrote:
Mon Dec 14, 2020 11:19 pm
If it is commercial bottled "spring water" all bets are off.
Yes, it's commercial bottled "spring water". I use it because unlike my tap water, it isn't chlorinated.

DonSchaeffer
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Re: Getting better pond water samples and specimens

#11 Post by DonSchaeffer » Wed Dec 30, 2020 6:48 pm

When I first started last Spring, I gathered grass from the edge of sidewalk, put it in sink water and waited just hours. Rotifers, a variety of ciliates, and amoebas emerged from the grass. This forms the basis of my current artificial puddle.

SWmicro
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Re: Getting better pond water samples and specimens

#12 Post by SWmicro » Wed Dec 30, 2020 7:31 pm

GeekyWife wrote:
Wed Dec 30, 2020 3:12 pm
chlorinated.
Fairenuf :)
But, no need to worry if it is chlorinated with chlorine, just leave to stand a while or boil.

If it is chlorinated with chloramine then that is slightly more involved to rapidly treat, or just leave to stand for much longer.

PS. all the above I mean for your little creatures when you find them,,, not for you to drink !

einman
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Re: Getting better pond water samples and specimens

#13 Post by einman » Wed Dec 30, 2020 11:49 pm

Hay infusions are great! If you can access some hay just put it in a jar and wait. Soon you will have a menagerie, assuming he hay was not treated in any way.

GeekyWife
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Re: Getting better pond water samples and specimens

#14 Post by GeekyWife » Sun Jan 31, 2021 2:48 pm

Fortunately, our local water system uses chlorine, not chloramines. So yes, leaving it to stand for a while for remove the chlorine.

Hobbyst46
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Re: Getting better pond water samples and specimens

#15 Post by Hobbyst46 » Sun Jan 31, 2021 4:11 pm

A good source for cilliates is decaying banana peels. Put some in a jar of water and let it stand on a shelf at room temperature. Equivalently, a bunch of dry hay. Within a few days the water becomes rich in protozoa.
However, a natural spring of non-polluted water is heaven for sampling IMHO, and offer biodiversity.
I would follow 75RR's suggestion above. Another possibility is to submerge some slides or similarly sized glass plates in undisturbed points of the stream or water reservoir. Among stones/rocks on the bottom, such that they are not strongly flushed by the streaming water. In a couple of days or weeks these may become interesting organism-sources.
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