IV-87 



Shrimp is a primary food item for various estuarine animals, includ- 

 ing red drum, spotted seatrout, snook, and gray snapper; but the 

 estuary undoubtedly provides more vegetation and debris for protec- 

 tion than open waters, and sufficient alternative foods exist in 

 the estuaries to remove some of the pressure from the shrimp. 



MENHADEN 



Spawning occurs at sea along the continental shelf, and the eggs hatch 

 in the ocean after about two days. Larvae move into the estuaries 

 as far as the freshwater interface. A transformation of physical 

 characteristics accompanies the entrance into the estuaries as larvae 

 grow and shift from being selective, particulate feeders to being 

 non-selective, filter-feeding juvenile menhaden which can tolerate 

 wide variations in both salinity and temperature. 



The menhaden population of a particular estuarine system seems to be 

 determined by the number of larvae entering the waters, food, oxygen, 

 competition, and predators. Because they are primary consumers, 

 feeding directly upon the natural vegetation, menhaden represent the 

 base of the food chain for many predators, such as the bluefish, 

 striped bass, and sharks. 



SALMON 



There are today only token runs of Atlantic salmon into a few rivers 

 in Maine to spawn, although in colonial times this species was 

 extremely abundant from the Housatonic River to the St. Croix River. 



