The research cruises are providing information on distribution 

 and extent of spawning of commercial as well as associated noncommercial 

 species of shrimp, according to season and area. The same information is 

 also being obtained for the larval stages. Closely allied to the latter study 

 is the shrimp larval identification project which successfully reared three 

 more species of shrimp to the protozoea stage. 



In addition to expanding the offshore aspects of the program, mark 

 and recapture experiments designed to obtain information on movements, 

 growth, and fishing mortality of offshore stocks of commercially exploited 

 shrimp were begun. Three experiments were completed. Pink shrimp were 

 marked with biological dyes on the Tortugas grounds in September 1961 and 

 on the Sanibel grounds in April 1962. A similar marking experiment on brown 

 shrimp (Penaeus aztecus) was completed off the central Texas coast in April 

 1962. Using data from the Tortugas study, it has been possible to make the 

 first estimates of fishing mortality of a commercial shrimp population. Ex- 

 cellent growth rate information was also obtained. 



The commercial fisheries statistics obtained by the Branch of Sta- 

 tistics are now being supplemented by biologists sampling the commercial 

 shrimp catch for species and size composition at selected Gulf ports. 



In 1961, there was a 35-percent drop from I960 in poundage of 

 shrimp landed in the South Atlantic and Gulf states. Much of the industry was 

 in distress and seeking assistance regarding the future of the fishery. In 

 early 1962, enough information on various aspects of the brown shrimp life 

 history was available to make a prediction for improved shrimp prospects 

 during the 1962 season. 



This prediction was based on comparable measures of shrimp abun- 

 dance obtained since 1959. Indexes of abundance were obtained for postlarvae 

 at the Galveston entrance and for juvenile shrimp from the Galveston Bay com- 

 mercial bait fishery statistics. In I960 and 1961, a strong correlation was ob- 

 tained between the postlarval and juvenile indexes and the subsequent catch of 

 commercial-size shrimp. 



In 1962, the postlarvae and juvenile indexes for the February -April 

 period v/ere similar to those of the good offshore fishing year of I960. Bait 

 shrimp (juvenile) production in May 1962 was the highest ever recorded for 

 that month. 



Primarily on the basis of these observations, good to excellent fish- 

 ing was predicted for the 1962 season. 



12 



