6-34 



as compared with the other two areas . This is probably related to the 

 combined factor of reduced pollution stress and increased physical 

 stability of the substratum. 



DiveY'si by 



Information- theory diversity values (Shannon- Weaver Diversity, 



Brillouin Diversity, Evenness, H and H . ) for all samples are 



max mxn 



presented in Appendix 1. The extreme variability of these parameters in 

 New Haven Harbor is apparent. Often the variability among replicates is 

 as great as the range of variability seen over an entire sampling per- 

 iod. Although there have been several attempts to relate absolute 

 diversity values to some observed or measured level of pollution-induced 

 stress, the applicability of diversity values as absolute indices of 

 environmental degradation has largely been dismissed. The consideration 

 of diversity indices in the New Haven Harbor program is generally 

 restricted to spatial and temporal comparisons of patterns of faunal 

 richness and abundance. 



Some patterns in the distribution of diversity values within 

 the harbor can be identified, however, even with the high within-station 

 variability. Brillouin diversity frequency distributions (H^) for 

 individual replicates from the R&M study are presented as histograms by 

 sampling period in Figure 6-7. Morris Cove and inner harbor stations 

 are presented as separate groupings and a third histogram combining all 

 samples is also included. Examination of these histograms establishes a 

 pattern of diversity in the harbor which is consistent with our earlier 

 observations of species richness and density. 



Morris Cove stations demonstrate a consistently higher range 

 of diversity values than inner harbor stations. In 1974, for example, 

 inner harbor diversities, rarely exceeded a value of 1.5. At Morris 

 Cove in 1974, values were frequently greater than 1.5, and often exceeded 

 2.0 even during March, the sampling period with the lowest mean diver- 



