The species diversities were low on the sound beach, averaging 

 between 1.0 and 2.0. Boesch (1972) recorded species diversities for 

 marine and estuarine habitats in Virginia. The estuarine systems of 

 the York and Pamunkey Rivers ranged from 1.5 to 2.8, with the lowest 

 diversities in the low salinity areas (0 to 5 parts per thousand) of 

 the upper Pamunkey. Gaspers (1967) indicated that species diversities 

 are low in estuaries, and Day (1951) stated that a complex of changing 

 parameters limited the number of colonizing organisms. 



The low diversities on the sound sites were caused by stress. The 

 oligohaline salinity of the zone and the periodic exposure by wind 

 tides resulted in the very low diversities on the nearshore sites of 

 transects IV and V. 



The oligohaline environment limited the diversity at the deep sites, 

 but the marsh area on transect IV decreased stress, and diversities 

 were slightly higher in that area. As the marsh develops and expands, 

 the export from the marsh should increase diversity in the surrounding 

 area. The species diversities within the marsh should rise as 

 additional species colonize the area. 



88 



