Further to my message of 22.10.02 re the lake in Minippi Park in eastern
Brisbane being choked by Salvinia, my thanks to the several good folks who
advised me of the possible biological control - a weevil, Cyrtobagus
salviniae, introduced to Australia by CSIRO.
I phoned the Brisbane City Council to try to be sure action was being taken.
Unfortunately the receptionist at the Council's "one phone number fits all"
was unable to 'fit' this one, and find an appropriate Council officer for me
to talk to. I just left it with her to pursue the matter and make sure the
message got through, because Ruth Kemp had already emailed me to say she had
spoken to Council and they were taking action.
Bob Forsyth, helpful as always, gave me two internet sites for information:
http://www.nrm.qld.gov.au/factsheets/pdf/pest/PP12.pdf
http://www.upperparrariver.nsw.gov.au/water_quality/facts/salvinia.htm
Confirmed my worst fears. Under the right conditions, Salvinia can double
the surface area it covers in two days.
Think what this means: today you have a relatively insignificant patch of
Salvinia in your lake, it covers only one-sixteenth of the surface. But in
two days time it will cover 1/8; 4 days, 1/4; 6 days, 1/2; and in 8 days,
the lake is choked. Just over a week, to go from 1/16 to totally covered!
And I guess from then on it just packs tighter and tighter.
Bob says the weevil was used successfully in Mt Isa's Lake Moondarra. But
it seems that the colder the climate, the longer it takes for the weevil to
become established and get the upper hand, so to speak.
Here's hoping Brisbane is warm enough for a reasonably prompt control. The
Salvinia is certainly doing well. Didn't really need the top-dressing of
soil that it got from our drought-stricken interior - worst dust storm for
forty years according to the 'cretiniser' (TV). It surely was hot enough to
please a weevil in Brisbane yesterday.
Cheers
Syd
Birding-Aus is on the Web at
www.shc.melb.catholic.edu.au/home/birding/index.html
To unsubscribe from this mailing list, send the message
"unsubscribe birding-aus" (no quotes, no Subject line)
to
|
