The Colorado River -Matagorda Bay Study 

 Charles H. Koski 



The purpose of this project is to ascertain the probable effects on 

 estuarine fauna of reduced fresh-water discharge into the lower basin and 

 adjacent bays caused by proposed impoundments in the Colorado River water- 

 shed. This project is supported by funds supplied through the Branch of River 

 Basins, Bureau of Sport Fisheries and Wildlife, Region 2. 



Field operations were initiated in February 1962 to determine the 

 distribution and abundance of the estuarine fauna. With each being occupied 

 once every 2 months, three stations were established in the Colorado River 

 below the town of Matagorda, two in West Matagorda Bay (west of the river), 

 three in East Matagorda Bay, and two in the Gulf Intracoastal Waterway. (See 

 figure. ) Salinity and temperature measurements (surface and bottom) and a 

 5-minute trawl tow for biological samples were made at each of these stations. 

 An additional station was established at Parkers Cut, between the river and 

 West Matagorda Bay, to measure salinity, temiperatures, and approximate 

 current. Irregular bottom and swift currents prohibit trawling at this sta- 

 tion. Meteorological conditions are noted during each trip. 



/ 



COLORADO 

 RIVER 



GULF OF MEXICO 



BROWN CEDAR 

 BAYOU 



• = Sompling stotions 



Colorado River -Matagorda Bay sampling stations. 



In one West Matagorda Bay station, a 1/8-inch mesh nylon cover 

 was used over the cod end of the trawl net to obtain postlarval shrimp and 

 other small forms, which would normally pass through the larger mesh of 

 the net. 



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