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distribution of the samples. Another approach, as described by S. Weinberg
and D. Pfeifer 42 , was sampling the so-called “minimal area”, regarded as
the smallest observation area for a representative collection of most of the
abundant species of higher taxa. This approach calculated the minimal
area but eliminated rare taxa from the analysis; depending on the taxonomy
level, it did not require large sample numbers but it could help to prevent
the exclusion of statistically important taxa. While this method
encompassed the main abundant taxa, it excluded some minor taxa and
thus probably did not meet the requirements of a diversity study. Using this
approach in analysing their data, DISCOL researchers had calculated
minimal sampling areas for future use in the same area. Such calculations
required samples from the area to be investigated. The results were:
?? For the megafauna, a minimum area of 10,000 m² to be observed
and evaluated, requiring an ocean-floor observation run at least 2 m
wide and 5000 m long;
?? For the macrofauna, an area of 0.5-1.5 m², equivalent to 2-6 boxcore
samples of 0.25 m² each, and
?? For the meiofauna, an area of 142-355 cm², requiring 2-5 multiplecorer
tubes of large size, 71 cm² each.
The programme for calculating the minimum area was available from
Professor Dietmar Pfeifer of the University of Hamburg (Germany).
Suggestions for future experiments
Schriever then discussed how future experiments might differ from
DISCOL, which had consisted of baseline studies, the disturbance and four
post-impact studies. Based on their evaluation of data, DISCOL researchers
suggested starting with a pre-baseline study to get information about
currents and topography along with an initial sampling of megafauna,
macrofauna and meiofauna, so that minimum sampling areas and the
required replicates of gear could be calculated. This should take place
about one year before the baseline study, to allow evaluation in the
laboratory. The current-meter chain should remain in place for at least one
year, with the data to be evaluated onboard at the beginning of the baseline
study. Afterwards would come a pre-impact study, the disturbance, the first
impact study directly after the disturbance and four more impact studies up
to ten years after the impact. They suggested one more impact study
because they had ascertained that the faunal composition was still different
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