the overall condition of the plants began to deteriorate immediately 

 and continued to deteriorate through June 1978. The number of stems was 

 about 50 percent of those at area 3 in December 1977 and about 12 per- 

 cent in June 1978. Rhizomal shoot development was poor as compared to 

 areas 2, 5, and 6 during all monitoring periods (Table 6). The average 

 shoot height decreased to about 50 percent of that in area 3 by December 

 1977 and remained at that percentage through June 1978. Considering 

 the progressive deterioration of the plants in this area, it is doubtful 

 that this planting will result in long-term stability of the bank. It 

 is evident that new plantings are less tolerant to the destructive forces 

 of waves than are natural cordgrass-mussel communities. Once a stable 

 community has formed and the sediment surface is firmly anchored, indi- 

 vidual plants are not subjected -to abrasion by sand and shell fragments 

 propelled by waves. 



c. Alameda Creek (Area 5) Plantings . Area 5 is partially sheltered 

 from waves generated by the normal westerly to northwesterly winds. The 

 longest fetch in this area is about 7 kilometers. Sediment in this area 

 contained sand and pulverized shell fragments. Cordgrass-mussel bio- 

 constructs planted in this area had 100 percent survival and good plant 

 growth through June 1978. By December 1977 the plants were significantly 

 taller than those in area 3, and the number of stems per bioconstruct 

 was about equal to that in area 3 (Table 5) . A mean of 78 stems per 

 bioconstruct was recorded for area 5 in June 1978. This density is com- 

 parable to that of the fully developed cordgrass-mussel community at 

 area 3. Although no natural cordgrass-mussel communities were monitored 

 in the 23 marsh sites, it is evident that stem densities are lower when 

 cordgrass grows in association with mussels. Rhizome production and 

 growth of bioconstructs were high in area 5 (Table 6) . Based on 13 

 months of observation, it appears that the cordgrass-mussel bioconstructs 

 will eventually stabilize area 5. 



d. Alameda Creek (Area 6) Plantings . Area 6 is located along Ala- 

 meda Creek and is sheltered from waves with a fetch of less than 0.5 

 kilometer in any direction. Cordgrass-mussel bioconstructs planted in 

 area 6 exhibited good plant growth within a few weeks. The number of 

 shoots, including rhizomal shoots, continued to increase during the 

 winter period. Shoot height was significantly greater than that in the 

 other areas at all times, although there was some dieback by Februray. 

 The dieback was not a result of the death of inflorescence-bearing culms, 

 as was the case in natural stands, because of inflorescences developed 



in any of the areas. This area demonstrated cordgrass-mussel growth 

 under optimal conditions. Because of the absence of wave stress, this 

 area was superior in all growth characteristics measured. Stem density 

 in area 6 reached 170 stems per square meter (stems per bioconstruct) 

 and mean height was 9.5 centimeters. As noted earlier, the 23 natural 

 marshes averaged 650 stems per square meter with a mean height of 79 

 centimeters. The lower density and height in the bioconstruct plots is 

 in part due to their stage of development. However, it appears that 

 even in mature cordgrass-mussel communities stem density remains low in 

 comparison with areas where mussels are not present. 



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