Fig. 1.2 Sampling to detect an impact due to escape of fine sediments from dredging at×in areas
A, B and C in an estuary. In each area, there are sampling sites (•) within the distance predicted that
sediment would disperse if accidentally released (i.e. over the stippled areas in (a)). Control sites (◦)
are outside the predicted area of impact and at similar distances apart as the potentially impacted sites.
In (b) is the actual, much larger (stippled) area impacted; no impact would be detected because all the
controls are also affected.