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Re: Aquatic Plants Digest V2 #215

>CULTIVATED roses have a generally well-deserved reputation for needing a
lot
>of insecticides, as they are quite susceptible to insect damage.  Among
these
>various insecticides are some which are "systemic," in other words are
taken
>up by the plant and stored in the bark and wood.  Chewing and sucking
insects
>are then poisoned and killed, just by chewing or sucking juices from the
rose
>plant.
>
>If the rose wood was from cultivated roses, it might well have been
treated
>sometime with systemic insecticides, which would make the wood extremely
>toxic to fish.  I have no hard scientific "facts" to back this up, but it
is
>worth thinking about.  To make it more puzzling, only SOME of the fish in
the
>aquarium died.  Poisoning would be much more likely to kill ALL of the
fish.

Pesticides often interfere with the breathing aparatus of insects, and are
frequently taken in through the gills of fish, (or the lungs/skin of human
beings, much of my pesticide info comes from information for training to
apply pesticides (which I decided not to do) or from learning how to train
agricultural field workers about pesticide safety) resulting in death of
the fish, some species or individuals may be much less seceptible to small
concentrations of pesticides than others. 
	Some human beings exhibit symptoms of pesticide poisoning after exposure
to only a fraction of the quantity that may be required to induce symptoms
in others. I immagine that fish are the same way.
	Also, I recall that Neale satd that one of the healthiest survivors was a
betta, which has a great advantage in not having its sole source of oxygen
be the water.

Neale may have revealed another possible source of problems in this
message:

>I did of course think of whether their were pesticides in the wood (albeit
>after the fish died!), but since we haven't sprayed the plants in over two
>years, and the wood had been cut and left on the compost heap all summer,
I
>doubted that was the problem.

	Compost heaps are rampant with bacterial cultures of all sorts, as well as
the various byproducts of decomposition, for instance, bacteria in rotting
hay (put away wet) can create so much heat that a fire may be caused. I'm
not sure how quickly these bacteria could load the aqurium with toxic (to
fish) byproducts, or perhaps use up much of the available oxygen, but it
might be quite quick in the nutrient rich waters of an aquarium, again,
this would pose little problem to a labrynth fish like a betta. 
	I would suggest boiling anything that had spent time on a compost heap
before even concidering putting it into an aquarium with fish. 

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