15. BOUMA, A.H., and HOLLIDAY, B.W., "Shell Dredging and Environmental Impact 

 Statements," Symposiim on Ocean I4ining, OSM 11, World Dredging Conference 

 Association, 1973, pp. 66-84. 



An environmental impact study was required for San Antonio Bay, Texas, to 

 determine the influence of shell dredging on the bay environment and on the 

 adjacent Aransas National Wildlife Refuge. Industry and nonbiologically oriented 

 agencies recognize a degree of harmful effects inherent to shell dredging, in- 

 cluding silting of exposed oyster reefs. Other groups and agencies heavily 

 oppose dredging because it may destroy certain benthic species and the food 

 chain of other animals. Comparisons with other states reveal that a proper 

 management program should be initiated to evaluate the problems in these two 

 viewpoints. 



16. BOUMA, A.H., HOLLIDAY, B.W., and HALL, G.L., "Environmental Statement on 

 Shell Dredging: San Antonio Bay, Texas," Sea Grant Publication TAMU-SG- 

 74-104, Proceedings of the Sixth Dredging Seminar, Mar. 1974, pp. 38-58. 



A study of the environmental effects of shell dredging in San Antonio Bay, 

 Texas, on the Aransas National Wildlife Refuge and the adjacent bays was under- 

 taken by a team of approximately 50 investigators. Certain changes to the bay 

 environment, which were a direct result of dredging, were studied and evaluated. 

 These changes included circulation, aquatic life, population density of dredge 

 holes, feeding habits of fishes, oyster reef distribution, dispersal of pollu- 

 tants and navigation routes. Other studies dealt with the effect of spoil 

 distribution from dredging operations on live reefs, dredging fossil reefs, 

 and implantation of artificial reefs. In addition, the effect on the economy 

 and revenue to the State, due to the termination of shell dredging as a detri- 

 mental measure or due to the depletion of resources, was discussed. 



17. BROWN, C.L., and CLARK, R., "Observations on Dredging and Dissolved Oxygen 

 in a Tidal Waterway," Water Eesouroes Research, Vol. 4, No. 6, 1968, 



pp. 1381-1384. 



Evidence indicates that resuspension of oxidizable bottom sediments in a 

 tidal waterway caused significant reductions in the dissolved oxygen concen- 

 tration of the water. During dredging, dissolved oxygen was reduced 16 to 83 

 percent below normal. 



18. BRUER, J. P., "An Ecological Survey of the Lower Laguna Madre of Texas, 1953- 



1959," Publications of the Institute of Marine Science, Vol. 8, University 

 of Texas, Austin, Tex., 1962, pp. 153-185. 



Hydrographic data and comments on the distribution and habits of marine 

 species are presented for the lower Laguna Madre of Texas, a shallow, hyper- 

 saline marine bay extending 122 kilometers north of the Rio Grande delta. In 

 summer, waters of the gulf move northward through the lagoon with increasing 

 salinity due to evaporation. The various species in the plankton and bottom 

 communities diminish with distance from the pass. In winter, the flow is south- 

 ward. A population of commercial oysters, Crassostrea virginioa, near the pass 

 apparently is adapted to high salinity conditions. Some ecological effects of 

 manmade changes are described, including the effects of opening Port Mansfield 

 Pass, the isolation and silting of South Bay due to dredged material disposal, 

 and the management of the Rio Grande River during floods. 



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