Table 4. Spearman Rank Correlation (BEST Bio-Env analysis) between echinoderm community structure and 14 main environmental variables (see Table 1 and text for details and abbreviations).

a. 16x collectionsecoregions included	rho	best variable combination	best single variable
NEP, NWA, CAR, ARC	0.948	SST, INP, NUTC	SST (rho = 0.0.894)

Analyses were based on Theta dissimilarity of taxa on the ecoregion scale correlated with environmental variables on the ecoregion scale for A. echinoderm assemblages from 16x quadrat collections; and B. echinoderm assemblages from 100x quadrat collections. Best variable combinations yielding the highest correlation coefficient are listed. In addition, correlation coefficients of the single best variable are listed.