Figure 15. — Two types of containers used to transport stained shrimp to the sea floor. The disposable container now 

 in use Is on the left. When the block of salt dissolves, the container springs open. 



being used. The box is dropped overboard 

 while a vessel is underway. About 10 minutes 

 after the box reaches the water and begins 

 to sink, it springs open when a cube of 

 compressed salt that holds it shut dissolves 

 (fig. 15). 



Each of the refinements of equipment re- 

 quired for staining shrimp has increased the 

 efficiency of the operation, and some have 



led to releases of shrimp in better condi- 

 tion than previously. The three most recent 

 mark-recapture experiments have in- 

 cluded releases of between 7,000 and 12,000 

 stained shrimp; whereas, former ex- 

 periments were limited to much smaller 

 numbers. 



Charles E. Knight, Project Leader 



18 



