Norm Meck on Green Water . . .

[Russell Peters]

Quote: Originally Posted by MikeM LOL. Yes, but who is excluding what and when? ....The real devil is in the "how".

As JR says, it is just competative exclusion and the way we deal with it is that we add the heterotrophic bacteria we want to "win" each week in large numbers. They work until it freezes, so when it gets colder we add more.

Russ

[KoiCop]

now that you're here, I guess the game's truly afoot.

Whilst I'm perfectly willing to agree that competitive exclusion is the primary force at work in maintaining the desired result in a mature and properly stocked/maintained koi pond, there would also appear to be less understood forces at work in the lead up to that algal equilibrium.

Would you please address this excerpt from Norm's paper:

THERE IS SOME COMPONENT IN CLEAR ESTABLISHED POND WATER THAT IS TOXIC TO THE BLOOM ALGAE

A third set of tests was conducted using the same procedures as the second test set except the filtered pond water samples were diluted with varying amounts of aerated distilled water. The result of a 1 part distilled water to 1 part pond water dilution was the same as for the second test set, i.e. the starter bloom algae died quickly. At 2:1, the starter bloom algae did not immediately die but no significant growth was observed. At 3:1, some growth was observed but at slower rates than the first test samples. At 4:1, rapid bloom algae growth was observed, essentially the same as in the first test set. These results suggest that whatever this toxic substance is, when it is diluted down by about 75%, it is no longer an effective inhibitor.

THEORY: Based on these semi-controlled experiments, other experiments and observations, and from researched literature, this is what I think is actually happening in our ponds: When algae dies and is subjected to aerobic bacterial decomposition by heterotroph bacteria, a by-product of this process is a substance, released into the water, that is toxic to the living algae.

This theory is exactly the opposite of competition effects. [emphasis added. DPC]

[PapaBear]

Quote: Originally Posted by KoiCop ...A third set of tests was conducted using the same procedures as the second test set except the filtered pond water samples were diluted with varying amounts of aerated distilled water.

Not James, but I'll chime in. Feed alagae (or ANY form of plant life for that matter) distilled water and it will starve to death. No toxic competition required. Distilled water contains zero nutrient value, even you and I would become sickly if we relied on it for liquid sustinence. It is devoid of minerals needed not only for nutrition, but for the basic function of cellular activity at its most rudimentary level.
Conclusion, the third set of tests is flawed and completely irrelevent to the competetive exclusion aspects of the discussion.

[KoiCop]

whoops, you must have missed this from Test #2:

A second set of tests was made with the water samples taken from clear, established ponds. The first of these samples was filtered through a coffee filter to remove most particulate matter but not any of the microorganisms. A second sample was then additionally passed through a micron filter to remove any microorganisms larger than 2 microns. Identical quantities of nutrients and starter as in the first test set were added to both samples. Most of the starter bloom algae added to these samples died within just a few hours and ended up as sediment on the bottom of the containers. [emphasis added. DPC]

In Test #3, he started diluting the solutions and observed that as the dilution increased the algal growth increased.

[PapaBear]

I understood the dilution rate to be increasing pond water ratio to distilled. The verbage is a bit vague.
For algae growth in distilled water to increase, more nutrients must be added as distilled water in incapable of sustaining cellular osmotic function unless I've forgotten everything I ever learned in biology and physiology . (that'd really suck )

[KoiCop]

Norm's paper is 11 pages long and I only extracted a few key paragraphs for JR to comment on because competitive exclusion would not appear to explain Norm's experimental results.

Sorry for the confusion -- I recommend reading the entire enchilada to get properly oriented.

[johnsmith]

Hi Don, I suspect old Norm was curious about barley decay as a controler of blank weed and later- some how applied to green water? In that case, the combination of barley decomposition and the bacteria species that cause the decay, combine to add a TEMPORARY chemical to the water that inhibits blanket weed ( for sure) and some believe green water ( not proven). Please note that this is in a none circulating system like a field pond. When duplicated in koi ponds, it has been demonstrated that new pond syndrome maturation will correct this problem more reliably than the momentary release of enzymes/chemicals of barley decay ( mineralization) by heterotrophic bacteria. And of course, all koi ponds eventually battle through new pond syndrome ( and associated difficulties such as green water, cloudy water etc) as the competitive exclusion principle is completed.

Honestly I see two flaws in Norm's experiment that make his conclusions shakey. What Norm need to do are two things- isolate the species he suspects, culture it and have it attack green water. Isolation is critical to his theory as without that there are way too many factors including the simple reality of competitive exclusion to make his theory anything more than wishful thinking. He also needs to address the concept of luxury nutrient and the ability of dying algae cells ability to pass on this vital material to future genrations of cells. This variable is not effected by new water- at least not initially.
JR

[MikeM]

Well, JR, I guess I disagree to a limited extent. I agree with the basics of your post, but think there is a role played by allelopathy which is just as natural as nitrifiers colonizing available surfaces. In a two year study of phytoplanktonic growth in 6 Spanish ponds (natural ponds, not koi ponds), L. Serrano and C. Guisande reported in the International Journal Limnology (1990) in an article "Effects of Polyphenolic Compounds on Phytoplankton", that the natural phenol concentration in the water varied between 4 mg/l and 26 mg/l primarily in relation to seasonal flooding of the ponds. When phenol concentrations were above 10 mg/l there was little algal growth. When phenol concentrations were low, phytoplankton thrived. Typically the release of phenols bt healthy, living plants would be quite small, but a number of studies have found that there is a considerable storage of phenols and other alelochemicals in plant tissues, which are rapidly released when a plant dies and decomposition sets in. For example, A. Otsuki & R.G. Wetzel, 19 Limnol. Oceanog. 842-845 (1974), "Release of Dissolved Organic Matter By Autolysis of A Submersed Macrophyte, Scirpus subterminalis". The Serrano & Guisande report was supported in the same journal in a 1993 study authored by B. Kim and R.G. Wetzel, "The Effect of Dissolved Humic Substances on The Alkaline Phosphatase and the Growth of Microalgae". Kim & Wetzel found that a 10 mg/l concentration of aquatic plant phenols was inhibitory to the growth of some (not all) species of algae and cyanobacteria.

It is known that algae are more actively releasing the chemicals they produce than other plants due to the cell structure being so open to the water. In a study from 30 years ago, K. Keating, "Allelopathic Influence on Blue-Green Bloom Sequence in a Eutrophic Lake" [Science] followed algae blooms over a 3 year period in a polluted pond. The sequence of algae blooms was related to water-borne inhibitors. It appeared the dominant algae released substances into the water (allelochemicals)which inhibited the predecessor algae ...and the possibility was suggested that the same chemical barrage may stimulate other algae.

Running much too long.... When thinking of seasonal shifts in the algae population of a pond, consider that seasonal triggers, such as temperature rise, are operating at several levels at once. And, that the volume of pond water being filtered through the cell walls of the algal community over the course of a day is going to be very substantial. ...Which do you suspect is the greater... the dry weight of the bacterial colony or the dry weight of the algal community?

[johnsmith]

And this paper has WHAT to do with koi ponds????
I think your study is a perfect example of 'succession'. Succession rates are linked to closed bodies of water such as lakes that go through complete species shifts and complete community reorganization and are known to not always be dominated by the same species. And this is very typical in these nitrogen rich lakes-

eudorina to pandorina to volvox to uroglena to mallomonas to dinobryon.

interesting stuff but having ZIPPO to do with a circulating koi pond. the old round peg in a square hole , I'm afraid. The ONLY time such succession rates occur in koi ponds is in new pond syndrome period. After that, a pond is in equilibrium with it's constant nutrient source.

JR

PS and of course blue green algae is not actually algae! It was actually reclassified as a bacteria after some of these studies you posted. If you have substantial blue green algae growing in your KOI POND, you have bigger problems than competitive exclusion!

[johnsmith]

Mike and Don, lets try this another way--

Lets get Norm to complete his experiment to the point where the special toxins from his bacteria have beaten back all green water and algae. Then lets slow circulation ( lower oxygen), stop all water changes, warm the water and add both nitrate and phosphates. I assume the special toxins are a constant and build up even higher once the water changes have stopped? What do you think we might see at that point?

JR, the devil's advocate