Figure 2-12: Example of Rangia middens {i.e., piles of bi-valve shells) found in Nueces Delta. This location 

 is along the southern edge of the central Rincon Bayou channel. 



Photo courtesy of University of Texas Marine Science Institute. 



'From a man who lived by the abaters of Nueces Bay 

 we rented a sail boat, at four bits a day. . .. Into this 

 hay empties the Nueces River, and at the junction of the 

 two is a mud flat, miles in extent The river is deep 

 and narrow, but at its mouth spreads out, as it were, to 

 cover this great surface with an inch or two of water. 

 The amount of water over the flat depends in a great 

 measure upon the wind; a hree;^efrom the east sending 

 the water from the bay over the shoals, while a strong 

 current of air from the west will have an opposite effect 

 and leave the crest of the flat above the water's edge. 



"From various sources I learned that years ago the bay 

 had extended several miles further back than now, and 

 that the boggji soil on the sides of the river was at that 

 time just such aflat as the one I have described If this 

 is true there is no reason why the whole bay may not in 

 time be replaced by land. Such a radical change as this 

 is to be hoped for, for if there are seventy five square 

 miles on this earth that disgrace it, those seventy five 

 square miles may be found here, Nueces Bay being one 

 big slimy slough, only fit for the habitation of alligators 

 and mud-snakes " (Peirce 1984). 



Peirce's description of the dynamic rate of siltation in 

 the delta indicates that there was, during that period, a 

 very large amount of sediment was moving down the 

 Nueces watershed and into Nueces Bay. In fact, 

 Morton and Paine (1984) have reported that the 

 shoreline of Nueces Bay had been accreting 



(advancing) into the bay for much of the period 

 between 1867 xmtil the time of their research in 1982. 

 White and Calnan (1990), who compared historical 

 photographs of the lower Nueces Delta (below the 

 eastern-most MoPac railroad) with those taken in 1959 

 and 1979, also reported an increase in total delta area. 

 Between 1930 and 1959, the total area of the lower 

 delta (which included both vegetated area and barren 

 flats) increased by 164 hectares (ha) (405 acres), and 

 between 1959 and 1979, increased by 52 ha (133 acres) 

 (White and Calnan 1990). This process of down-basin 

 transport of sediment was also subjectively verified in 

 the 1930's and 1940's, when La Fruta Dam, 

 constructed in 1935 on the lower Nueces River, began 

 to lose a significant amount of its storage capacity due 

 to siltation (Corpus Chris ti 1990). 



However, although in recent years the total area of 

 the lower delta has increased, the total vegetated area 

 has decreased and the total water and barren areas 

 have increased. During the 49-year period between 

 1930 and 1979, the total area increased by 216 ha 

 (534 acres), but the water/barren areas increased by 

 345 ha (852 acres), for a net loss of 129 ha (318 acres) 

 of vegetation (White and Calnan 1990). Subsidence 

 (Brown etal 1976) and the loss of fluvial sediments 

 from the Nueces River were identified as possible 

 mechanisms causing the increase in water and 

 barren areas and the loss of marsh vegetation 

 (White and Calnan 1990). 



Chapter Two ♦ 2-13 



