Figure 262. Comparison of mean species percentages in the water-column and the sediments. Species with enhanced presence in surface sediment samples. Data pooled in 5 x 5 degree Marsden squares and averaged for water column (plankton and sediment traps) and sedimentary materials separately. For those Marsden squares where data for both the water-column and the sediments were available mean proportions in the sediments were substracted from the mean proportions in the water-column. N values indicate total numbers of original data points involved in each comparison. Graphs are restricted to species where a strong bias toward the sediments is apparent.