because of the reduced transport of exported materials 

 and the loss of habitat needed by migratory and 

 nursery-dependent species that utili2e the delta. 

 Therefore, without freshwater inflow, the delta is not a 

 functioning component of the greater Nueces Estuary 

 ecosystem. 



SUMMARY 



Since 1982, the average annual amount of freshwater 

 inflow to the upper delta has decreased by over 99% 

 compared to the period before 1958 (Irlbeck and Ward 

 2000). This dramatic change indicates the large degree 

 to which human activity has altered the delta ecosystem 

 in a relatively short period of time {i.e., less than a 

 quarter century). Nevertheless, the demonstration 

 project successfully increased the amount of fresh 

 water diverted into the upper Nueces Delta by six or 

 seven times that which would have occurred without 



the project. Although this amount of restored inflow 

 was relatively small (only about 2% of the annual 

 average before 1958) when compared to historical 

 volumes, it returned a significant degree of ecological 

 function to the Nueces Delta and Nueces Estuary 

 ecosystems. Prior to the demonstration project, 

 persistendy high salinity concentrations severely 

 inhibited the function of the delta, and its natural 

 contribution to the greater estuary ecosystem was 

 limited to infrequent periods when natural flow events 

 occurred. With the restored regular interaction 

 between the river and Rincon Bayou, fresh water and 

 nutrients were more consistendy introduced into the 

 upper delta, stimulating critical chemical and biological 

 processes. As a result, habitat in the delta component 

 of the Nueces Estuary improved in both quality and 

 quantity, and foraging opportunities for many estuarine 

 species were increased. 



7-10 ♦♦♦ Synthesis and Conclusions 



