Table 4. Effect of reductions in numbers of taxa on the Benthic Response Index (BRI).

Percentage of species with tolerance scores included in BRI-P	No of species with tolerance scores included in BRI-P	BRI-P vs. BRI Pearson Correlation Coefficient	No. of stations with BRI-P values
10	46	0.67	380
20	92	0.76	457
30	139	0.80	488
40	185	0.83	490
50	231	0.89	493
60	277	0.87	493
70	323	0.88	492
80	370	0.90	493
90	416	0.92	493
100	462	0.99	493

BRI-P values could not be calculated for stations where no species with tolerance scores were present in the data after the reduction.