Natural and altered estuarine habitats of penaeid shrimp.

This study demonstrates what can happen to a shrimp nursery area when it is altered by bulkheading. Two areas in Clear Lake were chosen - one adjacent to an unaltered vegetative shore and the other near a concrete bulkhead. Both had similar hydrology and sediment types, but differed in the amount of organic detritus in the bottom sediments and in water depth. Intensive sampling over a 10-month period produced 2.5 times more brown shrimp (Penaeus aztecus) and fourteen times more white shrimp (P. setiferus) from the natural habitat than the bulkheaded area. This preference for the unaltered habitat depended on the physical rather than the hydrologic characteristics of the habitat.