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Smallaxe! Interesting info on smelly lake syndrome

Discussion in 'Organic Lawn Care' started by ICT Bill, May 18, 2008.

  1. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,115

    This is from another discussion on another board about using protozoa to control misquito populations. Elaine chimed in with some interesting information and maybe some contacts to follow up on. Please read below, I had never thought of this issue from this direction

    Protozoa eat the young larval stages of the mosquito.

    In good water with lots of air, the protozoa best at eating all that zooplankton type of life are the flagellates and amoebae, along with a few ciliates.

    When water gets stagnant, the flagellates and amoebae diminish in numbers and activity. Only protozoa are left, but when water gets really bad, not even the ciliates are left, and that is when mosquitos get to be really bad.

    Fish fry - the youngest stags of fish after they just hatch - are also really good at eating mosquito larvae, and eggs too.

    But again, if water is stagnant and putrid, i.e., anaerobic, then these biological controls measures are non-existent as well.

    Algal blooms are significant players in this, and work by Steve Carpenter at the Univ. of Wisconsin showed, back some 15 or 20 years ago, that algal blooms are the result of losing the zooplankton, which of course, includes both the groups I was pointing out above.

    The zooplankton were lost, in the case of Lake Mendota, because the fish that consume the things that eat the zooplankton were being eaten by the sports fish that the US Fish and Wildlife were stocking the lake with.

    They stopped putting in pike and European trout (don't ask me the species, I'm not a fish person), and allowed people to take any and all of those species when they caught them, but the native sunnies, and a different trout and something else had to be released.

    The population of fish that eat the fish that eat the zooplankton rose back to pre-European levels, the zooplankton now started consuming mass quantities of algae, and there was no algal bloom on the lake again.

    As a student, I remember being able to walk across the lake on the algal mat that bloomed every summer. The smell mid-summer from the lake was awful when you sat at the beer garden at the Univ of Wisconsin, which is right on the lake.

    And the mosquito problem was notable, even for a place like Wisconsin, where the state bird is the mosquito.................

    I remember professors saying that algae PUT oxygen into the water, so how could the algal blooms be causing a problem?

    Think it through..................

    Think you have the answer? then read on.......

    Sunlight only penetrates one or two cells depths when a mat starts to develop.
    By the time a mat is thousands of cells thick, the cells on the bottom of the mat are no longer alive, and the bacteria grow so fast on all that dead sugar-containing algal material that the bottom side of the mat goes anaerobic by the time the mat is just maybe 10 to 100 cells thick.

    Expand that problem over the whole of one end of the lake, and you can imagine the smell.

    and the mosquitos happily eating all those bacteria and getting to adult size in no time flat.......

    Steve got the USDW to change the fishing regs, and within one summer, the algal blooms practically disappeared, and the mosquitos are now just normal at the beer garden.......

    If an effort was made to add the necessary organisms to the lake, if the regs would prevent people from using chemical fertilizer to the lawns around the lakes and streams, the even those few mosquitos would likely not exist either?

    What would birds eat?

    Worms. all those worms that would be back in the lawns, where they are supposed to exist........
    but can't because of the toxic level of chemicals poured on those lawns.
    OK, we are all working on putting an end to that insane amount toxic material going on soil, right?
  2. lawnsbytim

    lawnsbytim LawnSite Member
    Posts: 47

    Ah yes - the Memorial Terrace at the student union on Lake Mendota. The DNR has lowered panfish limits from 50/day to 15 - resulting in good populations of blue gill and sunnies. Catch and release on smallmouth bass has increased numbers and size. I think they still stock muskie. The county has gone to a phosphorus ban on all lawn fertilizers to help with the algae bloom, and is trying to curb runoff from farms upstream. The lake is much cleaner then 15 years ago as evidenced from increased mayfly hatches. The milfoil is a huge problem as those beds die off in fall and winter, and the decomposing plant matter creates anaerobic conditions. Promotion of rain gardens and rain barrels keep some of the nonpoint runoff in check. Some of the cities are creating sustainable committees and organic lawn care is one of their agendas. Stuff is getting better.
  3. treegal1

    treegal1 LawnSite Gold Member
    Posts: 3,911

    there is no mystery there, another great micro herd thats easy to grow if you are patent. nice post, lets get some photos going.
  4. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,081

    Then imagine how much cleaner it would be if the anaerobic organic matter was removed. Things like rotting leaves and dead milfoil.

    I can't speak to Lake Mendota, but what I call the 'transition zone' does all the things mentioned in the article, in many lakes around here. [The transition zone is the waters edge that fills up with leaves and expands into the water a little more every year.] Aerobic decomp above the surface, anaerobic below the surface. No fish fry in the tz.

    Next step is water lilie proliferation trapping/creating more om. When the cattails start the tz officially becomes misqito infested swamp land.
  5. Tim Wilson

    Tim Wilson LawnSite Senior Member
    Posts: 795

    Hi Y'all,

    Bill no offence to you as you are just relaying info but I thought I better let you folks know that general protozoa population increase is not a solution to mosquito populations. Protozoa are eaten by mosquito larvae, not the other way around. There is some research in protozoa having a pathogenic effect on mosquito larvae but it is not a simple process. I have no comment on the rest of the post but here was my response to Elaine's statement;

    "Protozoa eat the young larval stages of the mosquito.

    In good water with lots of air, the protozoa best at eating all that zooplankton type of life are the flagellates and amoebae, along with a few ciliates."

    ""I had trouble envisioning protozoa eating mosquito larvae which are roughly 2 mm ( 0.0787 or about 1/16th inch) in the first instar and grow to around 12 mm ( 0.472 or about ½ inch) by the fourth instar so I delved into the subject. http://www.entomology.cornell.edu/MedEnt/MosquitoFS/MosquitoFS.html

    There are some amoebae in pond mud which can grow up to 5 mm (0.197 inch) (Pelomyxa palustris)


    but I can’t picture them chasing and trapping mosquito larvae. There are some large ciliates in ponds called Stentors, which are fascinating creatures by the way, that are known to grow up to 3 mm and I suppose could conceivably choke down a first instar mosquito larva but apparently the largest prey on their plate is the smaller strains of rotifers and water fleas.

    The majority of protozoa found in pond life are between 5 and 200 micrometers (microns; um) (0.005 mm to 0.2 mm or 0.000197 to 0.00787 inch), the larger faster moving ones usually being ciliates. As you can see, apparently these are much smaller than the smallest mosquito larvae making consumption a rather daunting task.

    Typically though, according to literature, it is the reverse which prevails, with the protozoa amongst bacteria, fungi, rotifers, detritus and some tiny invertebrates being the food of choice for mosquito larvae.





    It could, therefore follow that an affected increase in the general protozoa pond population may result in an increase in the mosquito population.

    There are studies and experiments indicating that there are various microorganisms having a pathogenic effect on mosquito larvae http://www.ias.ac.in/currsci/aug252003/483.pdf
    amongst them being some strains of protozoa but one could hardly count on raising such specific lineage in adequate numbers with a simple straw infusion.

    Something that does work for mosquito control is the broadcasting on ponds of Bacillus thuringiensis variety israelensis (BT). This is a bacteria spore which when consumed by the mosquito larva ends up killing it. We have used this successfully for a number of years purchased under the brand name Vectobac. Although I am unsure of the potential downside to using this product the benefits seem to outweigh any bad effects so far and it seems harmless to other pond life such as dragon fly larvae, etc.

    If there is a general population of protozoa which feed on mosquito larvae, I can find no evidence of this yet.""

    A good rule I think is, no matter who is giving information which is not just opinion, check to see if they give references for literature. This includes me.

  6. NattyLawn

    NattyLawn LawnSite Bronze Member
    Posts: 1,643

    Thanks for the correction, Tim.
  7. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,115

    Thanks Tim, please follow up with the thread after that

    Maybe not
  8. Tim Wilson

    Tim Wilson LawnSite Senior Member
    Posts: 795

    Yah. Maybe not. I don't think it is that productive.

    Cheers Mate!
  9. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,081

    Too bad I can't find references as to why cleaning leaves out of the dead waters of lakes will help reduce the OM for algae bloom. :)

    Perhaps there is a GOOD reason to leave the debri in the water.
  10. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,115

    Smallaxe, I think you already know the answer to that. too much is too much

    If local building has changed the way water enters the watershed and is bringing debris with it, you will need to try to organize a watershed association to raise awareness and change practices

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