While shrimp catches are important, processing is a 

 necessity to distribute the various shrimp products. Shrimp 

 producers sell shrimp in several forms including fresh 

 headless, fresh peeled, fresh heads-on, frozen peeled, frozen 

 heads-on, frozen heads-off, canned and dried. The Louisiana 

 Advisory Commission (1973: 187-188) recommends that the 

 dockside value of commercial catches be multiplied by a 

 factor of between 2.5 and 3.5 to obtain the total worth of 

 production after value added in processing. Using a factor 

 of 3, a catch of 59.5 million pounds in 1974 (Table 3.2) is 

 valued at $32.2 million before processing and $96.6 

 million after processing. 



3.4 — THE OYSTER INDUSTRY 



The Eastern oyster, Crassostrea virginica Gmelin, 

 is the only commercially valuable oyster taken in Louisiana 

 waters (Pollard, 1973). Although Crassostrea virginica 

 may live in a salinity range of 10 to 30 ppt, it is usu- 

 ally found in salinities of 10 to 15 ppt. Large populations 

 of the Eastern oyster inhabit lower salinities compared to 

 many less tolerant oyster predators, such as the fungus 

 Dermocystidium marinum and the conch (commonly called oyster 

 drill) Thais haemastoma . These two predators cannot survive 

 in a low salinity environment. 



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