(2) Oceanic Drift Lines . A second type of drift accumulation present 

 on Nauset Spit-Eastham was oceanic drift lines similar to those described by 

 Chapman (1976; Fig. 84). Because Nauset Spit-Eastham is an eroding barrier, 

 these drift lines are rare. On the southern end of the spit, however, large 

 deposits of algae, Ammophila bveviligulata, and salt-marsh grasses accumulated 

 during the spring and early summer. One tide deposited debris which became 

 burled by sand during the next tide and covered by more debris, creating a 

 layered drift line as deep as 90 centimeters. Organic composition varies 

 by location with algae, Ascophyllum sp. and Fucua viecosum, the most common 

 elements in 1978. Samples of Ascophyilum collected from oceanic drift lines 

 were dehydrated. Weight loss was 79 percent. Many seeds and a wide variety 

 of plant fragments were present in these drift lines. 



3 







Figure 84. Oceanic drift lines. 



Oceanic drift Lines are densely vegetated by seedlings and regenerating 

 fragments that can tolerate high levels of salt spray. These drift lines, 

 high In nitrogen-rich algae and fine organic material, supported eight species 

 of vascular plants on Nauset Spit-Eastham ir. 1978 (Table 29). A total of 20 

 species of vascular pLants appeared in 7 oceanic drift lines sampled on Cape 

 Cod in 1978 and 1979 (Tables 33 and 34). 



(3) Bay D rift Lines. A third type of drift line found on Nauset 

 Spit-Eastham, similar to the one described by Chapman (1976), was located 

 along the dune and salt marsh Interface ar.d at the edges of washover features 

 (Fig. 85). Composed largely of salt-marsh grasses (Spartina patens and Spar— 

 tina alterniflom) , these drift lines were, following the February stora, 

 also rich in fine organic material torn from dunes and other eroded features. 

 Organic material floating in the bay waters was deposited at the highest point 

 reached by spring tides. In late March the first stable bay drift line was 



138 



