standardization of environmental data and information - International ...

e needed to elucidate data about dose-response, chronic disturbance, time
scales of recovery, bioturbation and plume dispersal. Given such information,
it would be possible to make predictions about potential impacts and to
optimise a sampling design. Such experiments could potentially be done at a
single location, and if they were done early, the information they supplied could
be used to design new sampling programmes at a variety of locations,
assuming that the results could be generalised to larger scales.
SUMMARY OF DISCUSSION
An engineer among the participants observed that the impact zone had
two areas of interest – the mining area, where the animals would be destroyed,
and the area where the plume settled (provided that the plume area remain
unmined, for otherwise it would fall in the first category). Why did the proposed
design, by suggesting two control areas to the one impact area, focus more on
the controls than on the impact?
Dr. Etter responded that his strategy was not to focus more on the
controls than on the impact, but rather to suggest a bare minimum course for
detecting the effects. It was known that in the area where the sediment had
been torn up there would be a strong impact. If the aim was to know exactly
what had happened in the impacted area, more samples should be taken
there. However, he did not want to force contractors to take many samples
where the results were going to be straightforward. On the other hand,
perhaps no one knew exactly what would happen in those areas. Therefore,
some balance had to be struck when deciding what information was wanted:
whether there had been an impact or how the impact changed from place to
place. To design a sampling programme, one had to know specifically what the
question was.
Asked how the sampling design took account of the fact that an impact
area would have places of heavier and lighter environmental damage, Etter
repeated that more sampling would be needed to deal with two different
questions: Did the light impact area differ from the controls? Did the heavily
impacted area differ from the controls? Another participant said the question
re-emphasised the need for dose-response experiments to avoid multiplying
studies ad nauseam.
One participant observed that statistical significance was measured by
levels of probability, with results falling below the 0.05 level being accepted as
significant. The amount of variability between replicates would determine how
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