I got my Master's Degree working with macroinvertebrates in surface waters,
so I find this study to be of great interest.  As I've mentioned in my
articles, I am greatly concerned about the effects of pesticide pollution
upon aquatic ecosystems.

So the question is whether the neonics are causing problems.  Allow me to
state clearly that I would fully expect high concentrations of neonics or
any pesticide in surface waters to cause species decline--especially of the
best indicator groups--stoneflies, mayflies, and caddisflies.

That said, let us now look more closely at the study.  First, look who it
was funded by: the Triodos Foundation’s Support Fund for Independent
Research on Bee Decline and Systemic Pesticides.

This funding source suggests that the funders had an expectation of what
they wanted the results to be, and also greatly limited the scope of the
"research" (actually consisting solely of statistical analysis of existing
data gathered by water monitoring entities).

The authors were not out to determine the causes of species decline, but
rather only looked to see whether imidacloprid appeared to have any
statistical correlation.  The authors make this clear.  The point being
that since imidacloprid is associated with bulb growing, one would expect
to find higher concentrations of it in bulb-growing areas (the southwest of
the Netherlands).  However, in those same areas one would also expect to
see high concentrations of some of the other up to 600 different compounds
monitored, including insecticides, herbicides, surfactants, fertilizers,
etc.  The study did not address the contribution by any of these other
compounds.

I personally have been involved in stream monitoring in California, and
have plenty of experience in seeing streams nearly devoid of aquatic life.
 No pesticides need be involved--simple exposure to fertilizers or road
runoff may be enough.  But if the only thing that a researcher looks at is
the concentration of imidacloprid, that is the only association that he is
going to find!

Even then, the associations for various individual taxa are pretty weak--as
imidacloprid concentration goes up a thousandfold, there is a far
lesser diminution of the abundance of a species.

Perhaps a better study to look at would be:

Current Pesticide Loads in Dutch Surface Waters
 http://www.academypublish.org/papers/pdf/442.pdf<http://www.academypublish.org/papers/pdf/442.pdf>

In this study, the authors conclude that: "It can be concluded that
pesticide loads in Dutch surface waters have declined, but not everywhere.
From 1998 to 2009 it can be said that in this respect there has been
a 70% improvement in general water quality."

Now Ghislain, before you jump down my throat, I'm not suggesting that
neonics could not be causing problems for ecological communities in surface
waters.  Indeed, I expect that they would cause problems in the
bulb-growing areas, in which they are vastly overused.  I'm simply saying
that we must carefully analyze each and every study before drawing
definitive conclusions.
-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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