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Re: Herbicides

> Time for some stupid questions....
> Being totally ignorant about algae and unwanted plants in natural waterways,
> I'm asking myself what is causing the problem in the first place.

Often it is human induced ....but not always. Some lakes/ponds are naturally
eutrophic and juicy. A nutrient rich system is good in some cases. I just
got back from one. Water levels have dropped, loads of driftwood!

> Is it
> fertilizers and other contaminants that we are dumping into the waters or
> letting leach into water ways that are the cause of these problems?

Certainly one of the causes. But it's also things like lawn fert's, oil from
boats and cars, urban runoff. Folks are quick to blame agriculture but the
effect of urban run off can impact a system/water shed. Channelization of
streams and swamps etc whwere once the system slowly absorbed nutrients are
now quickly swept out to sea or into the lake or river.

> Is it
> native plants/algae being introduced into eco systems where they would
> otherwise not occur naturally?

In some cases. But Hyacinth, Salvinia, Hydrillia, these are hell weeds from
the River Styx and are all over.

> I'm sure  it's not a natural occurance right?

Well, not always. Some are natural juicy and rich in nutrients. Most
generally are not and humans have done a great deal to muck up
lakes/pools/ponds and rivers/streams. I will not go into the marine systems.

> Is it too expensive or too late to do anything about fixing the source of
> the problem rather than resort to temporary solutions which some sound
> nearly as bad as the problem itself?

No, especially on a small pond like the original post. Draw downs on small
and/or shallow lakes is well suited and cheap.

You need not draw down that far in many case since in the deeper waters the
plants generally are not present. So if you draw down a shallow basin lake a
meter or so and it's only 2 meters deep, the new shore exposed will have
lots of dried dead plant matter.

Deep lakes are more able to buffer nutrient inputs but up to a point. They
generally don't have weed issues, nor rooted macrophytes like shallow lakes.
Draw down is rather ineffective there but they tend not have weed problems

I've seen a number of golf courses with bad weed issues in their ponds. I
consulted with one and told them to try the draw down and use the water for
irrigation and use the sludge for soil fertilizer. They did this and were
quite happy with the results.
Now I know what types of crap and herbicides, fert's these people put on
their course greens and the waste of water/land and on on, but draw down is
better than most alternatives where there is a weed problem. Another nursery
had a large lake with lots of floating algae mats, they did a similar thing
and it worked out great. They now use their lake as a holding pen for
irrigation water. They both get something useful and a method that is better
for everyone. The only real cost is the labor and energy to remove the water
and sludge which for many businesses like these and public works dept's,
they have the equipment and the operators to do this work.

The thing is, this exports the nutrients periodically out of the pond/lake.
If humans are putting it in there, they need to take it out or else you will
have weeds or algae or both. Humans can find uses for nutrient rich sludge
and nutrient rich water.

Nature is resilient but you cannot just keep dumping more nutrients/crap and
then add quick fix herbicides to solve all your problems. These are billion
dollar issues that should have some sort of management plan. Restoration and
creation can go a along way and improve the quality of life for humans and

Restoring a pond is not difficult and makes a good community local project.
Parks and nature preserves are nice next to your house/within anyone's

There's enough rampant development with little consideration for the natural
surroundings in most parts of the world. We certainly need the methods to
restore and create what we destroy. Quick fixes tend not to be the way with
planted tanks nor nature/ponds/lakes.

While many folks feel as if all is lost, remember attitudes towards nature
have changed, wetlands are not longer referred to in a negative detail in
Dante's fifth level of hell(read that account of swamps!). Folks are more
concerned about future management and environmental issues these days.
Attitudes can and do change fast. Hopefully fast enough to save some of the
Rainforest, swamps, lakes, temperate forest, other threatened environments.
Remember that plants grow fast when happy, but we have to give them a chance
to grow back. 

Saving what's left of nature will save us. Long after humans are gone, the
planet will grow anew. New species will evolve and exist. In the end, we
only screw ourselves by not taking care and managing what we have in an
effective manner. 

Tom Barr    





> Regards
> Giancarlo Podio