METHOD FOR COMPARING THE CAPTURE EFFICIENCY OF BENTHIC SAMPLING DEVICES

Traditional comparisons between the capture efficiency of sampling dev ices have generally looked at the absolute differences between devices . We recommend that the signal-to-noise ratio be used when comparing t he capture efficiency of benthic sampling devices. Using the signal-to -noise ratio rather than the absolute difference has the advantages th at the variance is taken into account when determining how important t he difference is, the hypothesis and minimum detectable difference can be made identical for all taxa, it is independent of the units used f or measurement, and the sample-size calculation is independent of the variance. This new technique is illustrated by comparing the capture e fficiency of a 0.05 m(2) van Veen grab and an airlift suction device, using samples taken from Heron and One Tree lagoons, Australia.