What are the positive and negative 

 effects of chancing the type of 

 habitat that occurs in the area 

 (e.g., rock vs sand)? 



Does construction-generated tur- 

 bidity clog fishes' gills or zoo- 

 plankton/filtration mechanisms. Do 

 avoidance mechanisms operate to 

 prevent this? 



Can loss of phytoplankton or mac- 

 rophyte primary productivity due 

 to structure shading constitute a 

 threat to an ecosystem? 



Can loss of phytoplankton or mac- 

 rophyte primary productivity due 

 to construction turbidity constitute 

 a threat to an ecosystem? 



What are the effects of structures 

 that protrude into the water or 

 channelize current upon the migra- 

 tion of fishes, mammals, and crus- 

 taceans? 



How do solid structures affect sys- 

 tems through alteration of circula- 

 tion? 



What are the biological effects of 

 structures such as rubble mound 

 groins or riprap revetments in 

 areas where this type of habitat 

 did not formerly exist? 



Under natural conditions, is avail- 

 able habitat one of the most impor- 

 tant factors controlling the produc- 

 tivity of a specific organism? 



What are the effects 

 wave energy patterns 

 ment composition and 

 biological productivity? 



of altered 



upon sedi- 



associated 



What are the zones of influence of 

 wave energy altering structures? 

 For example, how far away from a 

 bulkhead are the energy altera- 

 tions felt? Bottom profile and 

 sediment composition alterations 

 are included in this concern. 



What are the effects of various 

 types of submerged surfaces on 

 productivity? For example, does 

 a riprap revetment offer a better 



habitat than a bulkhead or con- 

 crete revetment? 



What are the cumulative effects of 

 many of the same type of struc- 

 ture in an area or a combination 

 of many types of structures in an 

 area? Studies similar to those on 

 bulkheadinc in Texas (Coastal Re- 

 gion 3) are needed in the other 

 coastal regions and about other 

 types of structures. 



What are the 

 structures on 

 wildlife? 



effects of shoreline 

 waterfowl and other 



142 



Answers to all the above questions 

 could be generated through field or lab- 

 oratory studies. There are certain ques- 

 tions, however, that could best be an- 

 swered through a literature review 

 which incorporates all three of the 

 aforementioned data bases. The results 

 of the literature review could answer 

 the questions or could serve as a firm 

 basis on which to design the required 

 field or laboratory studies. 



The case history studies for each 

 coastal region were selected based on 

 the recommendations of local U.S. Fish 

 and Wildlife Service personnel. Their 

 recommendations were based on the most 

 troublesome structures they encounter 

 when reviewing Corps of Engineers' 

 permit applications. In several cases, 

 there was not enough information avail- 

 able to write a case history, and theo- 

 retical case histories were constructed. 

 In other instances, the data base was 

 so poor that the majority of the case 

 histories was theoretical. Circumstances 

 where theoretical information was used 

 would seem to be appropriate topics for 

 detailed study. These topics were 



Southern California 

 Coastal Region 2 

 Bulkheads 



South Atlantic 

 Coastal Region 5 

 Groins 



South Atlantic 

 Coastal Region 5 

 E ulkheads 



