desired as an end result for that coast- 

 al area. The tradeoffs involved are dis- 

 cussed by Dolan (1966) and Dolan et al. 

 (1973). Altered salinity regimes in the 

 embayment can also affect life cycles 

 and productivity of various aquatic or- 

 ganisms, although this has been little 

 studied. 



CASE HISTORY - 

 COASTAL REGION 

 ATLANTIC 



BULKHEADS IN 

 6 - MIDDLE 



Within Coastal Region 6, a number 

 of references are available on effects of 

 bulkheads (Carstea et al. 1975a, Gantt 

 1975, Yasso and Hartman 1975, Chesa- 

 peake Research Consortium 1974, 1976, 

 Givens 1976). Most of the existing in- 

 formation refers to Chesapeake Bay, 

 but Yasso and Hartman (1975) discussed 

 bulkheads in the New York Bight. The 

 observations contained in the literature 

 are broadly applicable within this re- 

 gion, even though specific flora and 

 fauna will vary from location to loca- 

 tio n . 



Bulkheads in this region are used 

 primarily to protect upland areas from 

 erosion and to stabilize the existing 

 shoreline. Construction of bulkheads 

 with either steel or wood sheeting is 

 common. 



Impacts in this region due to con- 

 struction of a typical 150-ft (46- m) tim- 

 ber bulkhead and the associated dredg- 

 ing of 300 yd 3 (274 m 3 ) of fill were 

 considered in a theoretical case history 

 by Carstea et al. (1975a). In this case, 

 it was expected that there would be no 

 significant impact on water quality. The 

 increased turbidity would not affect wa- 

 ter quality significantly. There would 

 be minor air quality and noise construc- 

 tion impacts, and some organisms would 

 be directly eliminated by dredging and 

 burial. 



An alternative to the bulkhead con- 

 struction is the use of a revetment. 

 However, bulkheads provide mooring 

 facilities which may be desirable in some 

 situations. 



Once in place, bulkheads provide 

 protection for upland areas immediately 



behind the bulkhead; however, unpro- 

 tected areas adjacent to the bulkhead 

 may be eroded, and this can undermine 

 the bulkhead from the sides. Carstea 

 et al. (1975a) claimed that bulkhead con- 

 struction would have a positive effect 

 on water quality by stabilizing the 

 shoreline and reducing erosion. How- 

 ever, Gantt (1975) stated that scouring 

 may cause erosion at the toe of the 

 bulkhead and that unprotected adjacent 

 shorelines may erode because of the un- 

 dissipated wave energy resulting from a 

 bulkhead. Carstea et al. (1975a) con- 

 ceded that the roughness coefficient will 

 indeed decrease slightly with bulkheads 

 yielding an increase in the velocity and 

 the dispersion coefficient of the water, 

 but stated that, if properly constructed 

 and maintained, bulkheads will have no 

 significant effects upon erosion, sedi- 

 mentation, or deposition. On the other 

 hand, one can expect alterations to lit- 

 toral drift and currents, according to 

 Gantt (1975). Carstea et al. (1975a) 

 maintained that a small timber bulkhead 

 would produce no significant increase or 

 decrease in the storage capacity of the 

 water body and no additional drift pro- 

 blems. The differences in the conclu- 

 sions of these authors are considerable, 

 but may revolve around a different per- 

 ception of what constitutes a "signifi- 

 cant effect." Furthermore, a single 

 small bulkhead, such as the one consid- 

 ered by Carstea et al. (1975a), will 

 have much less of an effect by itself 

 than will many small bulkheads taken as 

 a whole. 



Biological impacts of bulkheads are 

 dependent primarily on the location of 

 the bulkhead, with upland locations pro- 

 viding the least damage. Construction 

 below the mean high water line is more 

 damaging, and construction below mean 

 low water is most damaging. Filling be- 

 hind a bulkhead will destroy organisms 

 located there. Isolation of marsh grass- 

 es from tidal waters will cause a loss of 

 part of marsh grass community (Carstea 

 et al. 1975a). Loss of wetlands will re- 

 sult in the loss of detritus production, 

 storage, and transfer of nutrients; loss 

 of feeding, breeding and nursery areas 

 for fish, shellfish, and the other organ- 

 isms; loss of flow regulation and shore 

 stabilization; and loss of habitat for the 



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