Results of the Trinity Bay Study 



Richard A. Diener 



The Trinity River watershed covers about 17, 635 square miles in 

 the eastern half of Texas. The watershed, about 350 miles long and 70 miles 

 wide, empties into Trinity Bay east of Houston. Trinity Bay, a part of the 

 Galveston Bay system, covers about 89,000 acres, and is a valuable estuarine 

 habitat utilized by numerous commercially important species of fish and crus- 

 taceans. This importance is reflected in Texas landings, of which approxi- 

 mately 98 percent by weight is composed of species that are in some way de- 

 pendent on estuaries. 



Water developinent plans 

 in the Trinity River watershed by 

 various private. State, and Federal 

 agencies have not yet been com- 

 pletely formulated, but these will 

 include projects for flood control, 

 navigation, and conservation stor- 

 age for municipal, industrial, and 

 irrigation uses. When considered 

 on an individual basis, each project 

 will reduce the fresh-water dis- 

 charge into Trinity Bay by only a 

 fraction, but when the effects of all 

 are compounded, the reduction of 

 fresh-water discharge will be con» 

 siderable. A large share of the 

 runoff would be returned to upper 

 Galveston Bay (near Trinity Bay) 

 by way of the Houston Ship Channel 

 and the San Jacinto River. 



The effects of the reduced 

 fresh-water discharge upon the fauna 

 and the existing water conditions of 

 Trinity Bay are of vital concern to 

 the welfare of commercial and sport 

 fishing interests in Trinity, Galveston, 

 East, and West Bays, and to offshore 

 species dependent upon these brackish waters for nursery areas. The Trinity 

 Bay field study by this laboratory (supported by funds supplied through the 

 Branch of River Basins, Bureau of Sport Fisheries and Wildlife, Region 2 ) 

 was conducted to determine what effects the projects would have upon the Trinity 

 Bay estuarine habitat and to formulate recommendations which would minimize 

 any detrimental effects. 



Trinity Bay sampling stations 



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