Friday, May 26, 2006


(And maybe some good news on species extinction)

Well, it's stacks on the mill over at Larvatus Prodeo, now that some idiot has let slip to Dr Jennifer Marohasy that yours truly had doen a bit of a hatchet job on her recent post on salinity in the Murray River. So much for the spell of ennui I was planning for the rest of this week and most of the next - I may have to go with the schadenfreude option instead. Fine by me, as long as I'm not the one providing the schadenfreude.

Moving right along, in a spirit of something approaching fair-mindedness, I recently downloaded Dr Marohasy's IPA backgrounder Myth & the Murray: Measuring the real state of the river environment (PDF) from the IPA site. So far I've only had time to skim the report, but this section piqued my interest:

The Cooperative Research Centre (CRCFE) survey Fish and Rivers in Stress: The NSW Rivers Survey is generally considered the most comprehensive survey of fish in the Murray–Darling Basin. The survey does not provide any data from which trends with respect to improvement or deterioration in fish numbers can be determined. However, the survey undertaken in the mid-1990s does claim to give an indication of the abundance of fish in the Murray River relative to other rivers.

The report’s principal conclusions include that ‘A telling indication of the condition of rivers in the Murray region was the fact that, despite intensive fishing with the most efficient types of sampling gear for a total of 220 person-days over a two-year period in 20 randomly chosen Murray-region sites, not a single Murray cod or freshwater catfish was caught.’ [Dr Marohasy's emphasis]

A good scientist is usually wary of an absence of data. An absence of data (namely, catching no fish) could be an indication that, for example, they got their sampling method (that is, their fishing technique) wrong, rather than that there were no fish.

I have no major disagreement with that last paragraph - I remember applying much the same principle in my own science education, years ago. If, for example, you wanted to check whether a stream was contaminated with E coli, you'd go out, collect water samples at various locations, take them back to the lab and then put yourself through the tedious business of mixing measured amounts of stream water with nutrient medium, incubate the mixture for a known period (corresponding to a calculable number of bacterial reproductive cycles), serially dilute the resultant cloudy broth then pour measured amounts onto agar plates. Once you got that done, you got to the fun bit - using the dinky colony counter machine to mark all the bacterial colonies on your agar plate, while the counter mechanism clicked over every time you pressed the special marker pen on the base of the plate.

The trouble was, if your agar plates were clean, you'd miss out on the fun bit with the colony counter. To make matters worse, you would have to conclude, on the basis of the available data, that the stream was totally uncontaminated by any bacteria, let alone E coli. Apparently, though, good scientists don't take this approach when it comes to the question of whether a river is contaminated by a particular species of fish. Finding no fish in the river, despite your best efforts to do so, is not enough evidence to infer that the river is most likely fish free. Well, you live and learn.

I suppose the same principle applies to potential bird contamination of wind-farm sites - well, it does according to Ian Campbell. All up, this has to be good news when it comes to species we used to think were extinct - for example, the continental USA is widely believed, on the available data, to be completely uncontaminated by Passenger Pigeons and the island of Mauritius, on the same grounds, is considered free of Dodo contamination. But clearly, we've got it wrong. Any day now, these lost species might turn up, like one of those two dollar coins that starts making an almighty ruckus when it falls out of one of your pockets in the clothes dryer. And for all we know, there might well be a few piles of unicorn manure somewhere that have been mistaken for the horse variety. no good scientist could rule ou the possiblity out on the grounds that everyone "knows" that unicorns aren't real.

Nah - I think I might take the ennui option anyhow. Too many pieces in the "to-be-completed" queue - like the next episode of that damned serial. And I owe myself at least a few hours of relaxing to great symphonies with rushed openings, missing repeated sections and sub-standard maestoso passages.

On the Domestic Front ...

Warning: this post includes information that may spoil your enjoyment of a favourite piece of recorded music.

Zeppo Bakunin's been on my case over the past couple of days on the subject of music theory - he reckons I should get into it as a hobby. All I'd need do, initially at least, is take myself off to the local library, or the second hand book shops, and start tracking down text books and other works of reference. And maybe a few miniature scores as well. Then perhaps I could start blogging on the subject of musical recordings and dishing the dirt on conductors who rush the openings of violin concerti or skip repeats in the last movements of famous symphonies. Or, a particular gripe that makes one set of CDs I've got more or less unbearable to listen to, record important sections of major choral works with key instruments in the orchestral score completely missing. It's a flute playing counterpoint grace notes to a trumpet part, for anyone who might be interested, and hearing the phantom notes in my head just isn't the same.

It sounds like a good idea as it would combine quite nicely with the blogging hobby, and I might eventually end up with the web-site to visit for tips on how to buy classical recordings. Such as - any conductor who gets through the fourth movement of Saint-Saens' Symphony No 3 op 78 (the "Organ Symphony") in less than 8' 28 is stiffing you on the Maestoso. That benchmark is taken from a 1982 Karajan recording. I chose it because, out of all the recordings available in the record shop where I bought it, it had the longest final movement. Old Herbie must have slowed down in his later years.

It also sounds like a bad idea - because right now, some of you at least, are looking at your CD racks where the Saint-Saens' Symphony No 3 enoys pride of place, thinking I really don't want to know. Bugger that Gummo Trotsky for bringing the subject up at all.