2 



UJ 200- 



Figure 14. — Abundance of postlarval white shrimp, Sabine Pass, Tex., 1963-66. Open 

 circles represent averages of four tows per month. 



to a depth of 14.5 m. (8 fathoms) off Galveston 

 was completed in March. This investigation 

 was undertaken to determine the role of 

 currents in transporting postlarval shrimp. 

 The data are now being analyzed. 



A cooperative inshore current study be- 

 tween our Laboratory and the Institute of 

 Marine Science at Port Aransas, Tex., began 

 in October. Institute personnel are releasing 

 drift bottles monthly at depths of 0.9, 12, 

 and 14.5 m. (3, 6, and 8 fathoms) at 18 

 stations between Port Aransas and Port Isabel, 

 Tex. 



Kenneth N. Baxter, Project Leader 



would equal or exceed those of the previous 

 3 years. The 1966 harvest was 153,000 kg. 

 (336,000 pounds), and the annual average 

 catch per trip was 56 kg. (123 pounds); 

 both greatly exceeded similar catches for 

 1963-65, 



The abundance index for postlarval white 

 shrimp in 1966 indicated that the white shrimp 

 harvest would be relatively low. The harvest, 

 369,000 kg. (811,000 pounds), exceeded the 

 1965 catch but was lower than either the 1963 

 or 1964 production. The annual average catch 

 of white shrimp per trip was 135 kg. (297 

 pounds), slightly more than half that of 

 1965. 



STUDIES OF POSTLARVAL SHRIMP 

 IN VERMILION BAY 



Prediction of Commercial Harvest 



Systematic sampling for immigrating post- 

 larval shrimp continued in Vermilion and 

 Cote Blanche Bays, La. These studies are 

 designed to investigate seasonal fluctuations 

 in abundance and to deternnine indices for 

 predicting the abundance of juvenile and sub- 

 adult shrimp in the bays. 



The abundance of postlarval brown shrimp 

 in 1966 indicated that the commercial bay 

 harvest of juvenile and subadult brown shrimp 



Postlarval Shrimp Identification 



Electrophoretic, serological, and immuno- 

 electrophor etic techniques were investigated 

 as possible methods of identifying postlarvae 

 of brown and white shrimp. Proteins from 

 postlarval and adult shrimp had similar 

 electrophoretic patterns, but postlarval mate- 

 rial yielded an additional protein band that 

 may be characteristic of this stage. This 

 method shows promise as a routine technique 

 for identification of postlarval shrimp. 



Charles W. Caillouet, Jr., Project Leader 

 University of Southwestern Louisiana 

 (Contract No. 14-17-0002-179) 



ESTUARINE PROGRAM 



The increasing national attention being 

 focused on the estuaries emphasizes their 

 importance and the need for strong research 

 programs to develop the facts to preserve 

 them and to manage their fishery resources. 

 The increasing rate of physical destruction of 

 estuarine areas by residential, connmercial, 

 industrial, and agricultural expansion is 

 readily evident. During the fiscal year, more 

 than 435 private projects -were proposed for 

 various types of construction in the coastal 

 waters and marshes of Texas. 



In recent years, about 16 percent of the 

 17,401 hectares (430,000 acres) of water and 



marsh in Galveston Bay has been destroyed, 

 severely damaged, or isolated; another 6 

 percent soon will be converted to a fresh- water 

 lake. If this destructive trend is to be halted, 

 the public, construction planner, administra- 

 tors, and legislators must be informed re- 

 peatedly of the value of estuaries as a natural 

 resource which contributes significantly to our 

 national economy and to the well-being of our 

 people. 



The role of estuaries in perpetuating renew- 

 able fishery resources is but one of its values, 

 but this value is great. The Gulf of Mexico 

 contributes one-third of the total commercial 



