The total carbonate and organic content (in grams per 100 grams) of 

 the sediments were recorded at each site (Tables 51 and 52) . The 

 carbonate content was low, ranging from 0.02 to 0.15 percent. There was 

 no significant difference between sites or sampling dates. 



The total organic content was also low, ranging from 0.11 to 0.97 

 percent. Organic content increased during the study, and was signifi- 

 cantly higher on site 1 of transect IV at the last sampling because of 

 the gradual marsh development on transect IV. 



f. Correlation Analyses . A correlation matrix was developed, 

 using the physical parameters and the major species. Twenty- seven 

 variables produced 351 nonredundant correlations (Table 53). The 

 correlation coefficients with season, transect, and site support the 

 analyses of variance. 



Sooleaolepides viridis was highly correlated with water depth and 

 horizontal distance from shore and R. cuneata was also correlated with 

 these variables. Both species were most abundant on the deep sites. 

 When wind tides exposed large areas of beach surface, shore birds 

 congregated in the area and fed on the exposed bottom. Several freshly 

 opened R. cuneata were discovered in the feeding area. The low densi- 

 ties of R. auneata and S. viridis on the inner sites are probably due 

 to predation, rather than to the species' inability to withstand 

 exposure. Leipdaatylus dysticus preferred the shallow, inshore sites 

 and was negatively correlated with depth and horizontal distance from 

 shore . 



A principal factor analysis with iteration and varimax rotation 

 (Nei, et al . , 1975) was performed on the correlation matrix; the nine 

 extracted factors, eigenvalues, and percent of variance explained are 

 presented in Table 54. 



The three major factors are interpreted below: 



(a) Factor 1. The factor loaded heavily for organic content, 

 oligochaetes, total organisms, tabanidae, and the dytiscid beetle, 

 Uvarus sp. These variables suggested that the marsh area was a 

 cohesive community and responsible for a major part of the variance in 

 the collections. 



(b) Factor 2 . The factor loaded heavily for site, horizontal 

 distance from shore, water depth, and the polychaete, S. viridis, and 

 is primarily a location factor. The heavy loading of S. viridis 

 indicated the organism's dependence on location, primarily distance 

 from shore. 



(c) Factor 5 . The factor loaded heavily for season, carbonate 

 content, temperature, and salinity. Factor 3 was a time and physical 

 parameter factor, because seasonal changes, marked by changes in 

 temperature and salinity, caused a large part of the variance in the 

 correlation matrix. 



79 



