EFFECTS OF BEACH NOURISHMENT AND BORROWING 

 ON MARINE ORGANISMS 



by 

 Syed M. Naqvi and Edward J. Pullen 



I . INTRODUCTION 



Shore erosion is a major problem along the U.S. east and west coasts and 

 along the Great Lakes, resulting in significant property damage, the loss of 

 land, and the loss of recreational beaches. Beach nourishment with dredged 

 material can provide a means of counteracting beach erosion in some coastal 

 areas. This is generally done by borrowing sediment material from offshore or 

 inshore locations and pumping the material to an eroding beach (Fig. 1), How- 

 ever, a massive displacement of the substratum can inadvertently disturb the 

 fauna and the topography of borrow and nourishment areas. Such an ecological 

 perturbation can extensively damage benthic nonmotile communities (i.e., corals 

 and clams) or cause habitat alterations (i.e., for sea turtles and fish). A 

 well-planned nourishment operation is important to minimize the ecological 

 effects, and may even be beneficial for certain marine animals, if environ- 

 mental conditions are favorable. 



This report summarizes the results of the latest research on effects of 

 beach nourishment and borrowing on coastal ecology. Based on experimental and 

 field studies, recommendations have been formulated especially for the benefit 

 of the coastal manager. It is emphasized, however, that physical and biologi- 

 cal conditions tend to vary from one geographical region to the next. There- 

 fore, strict compliance to these recommendations may not be feasible in all 

 situations. 



II. BEACH AND NEARSHORE ENVIRONMENT 



A coastal beach system includes the unvegetated part of the sandy shore- 

 line and the submerged nearshore area (Fig. 2). Ecologically, the beach system 

 is a specialized environment occupied by those animals that have the capacity 

 to adapt to the regular displacement of sediments. The coastal beach system 

 is generally in a state of dynamic equilibrium, continually shifting in re- 

 sponse to waves, winds, currents, and tides. Each part of the beach is capable 

 of receiving, storing, and losing sand. This depends on the constantly changing 

 natural forces. 



Sandy beaches provide a unique habitat for burrowing animals which 

 represent the majority of the invertebrate fauna. Several vertebrates have 

 also become an integral part of beach fauna. Fish, birds, and reptiles use the 

 beach for spawning, breeding, nesting, feeding, or just resting. There are 

 also other animals that are occasional visitors to the coastal beaches, e.g., 

 the sea turtles including the threatened loggerhead (Caretta aaretta) and the 

 endangered green turtles {Chelonia mydas) (Fletemeyer, 1980). In addition, 

 the shallow waters of the nearshore zone provide an excellent habitat for a 

 variety of shellfish and forage fish which, in turn, attract predatory birds, 

 fish, and man. 



