Figure 21. — Growth of juvenile oysters in natural and altered areas. ILI is initial length in- 

 terval in millimeters, and N equals the number of oysters placed in each area, Jamaica 

 Beach area, Tex. 1969 



sizes of the populations of the resident oysters. 

 A sizable population of oysters in the altered 

 area was attached to the bulkheads, whereas 

 few oysters were present in the natural marsh, 

 apparently because of the lack of a suitable 

 setting surface. Experimental oysters in the 

 natural marsh may have less competition for 

 food than those in the altered area. 



W. Lee Trent, Project Leader 

 Edward J. PuUen 

 Donald Moore 



GULF OCEANOGRAPHY PROGRAM 



We continued to process and analyze benthic, 

 hydrographic, and biological information col- 



lected from the Gulf of Mexico and Yucatan 

 Strait during the 1966-68 cruises of the R/V 

 GERONIMO. We emphasized the development 

 of methods to evaluate the quality of these data 

 so that we can describe the topography and 

 sediments of the sea floor over the Continental 

 Shelf, and the character and changes in the 

 overlying water in the areas of the shrimping 

 grounds. 



A chart of the bottom topography of the 

 Continental Shelf south of Tampa Bay, Fla., 

 is in preparation. We completed the southern 

 portion of the map, which includes the shrimp- 

 ing grounds in the area of the Dry Tortugas, 

 and are plotting the properties of the sedi- 

 ments. 



31 



