SURVEY OF OYSTER BOTTOMS IN MATAGORDA BAY, TEXAS. 



By H. F. Moore, 



Assistant, Bureau of Fislieries. 



OBJECT AND METHODS OF THE SURVEY. 



As stated in the general instructions governing the party, the sur- 

 vey had for its object "the accurate location and charting of all 

 oyster beds, scattering growths of oysters, and areas of bottom suitable 

 for oyster culture, or which can be made suitable, and also an inves- 

 tigation of the biological, physical, and statistical features relative 

 to the oysters and oyster fisheries of the region." The entire bay was 

 embraced in the original scheme of the survey, but the work was much 

 retarded by the inclemency of the weather during the winter, and it 

 was found impracticable in the time available for the purpose to 

 cover more than the region lying above Half Moon Reef. This 

 region, however, is by far the most important part of the bay from 

 the standpoint of the oystermen, and during the season of 1904-5 it 

 yielded practically the entire product used in the oyster houses. 



The work was thoroughly done, and the location of oysters and 

 soundings can be vouched for. It was practically a hydrographic 

 survey, on which were superimposed the special investigations per- 

 taining particularly to oysters. Projections showing the location of 

 triangulation points used in former hydrographic and topographic 

 surveys of the bay were obtained from the Coast and Geodetic 

 Survey, together with descriptions of the permanent marks. Three 

 of these triangulation points (Sevenmile, North Base, and West 

 Point) were recovered and used in the location of the signals erected 

 at convenient intervals on the shore, and three others (South Base, 

 Duncan, and East Point) were recovered, but not occupied. The 

 shore lines, which in places differed considerably from the delinea- 

 tions of the projections and charts, were located from three-point sex- 

 tant observations at intervals of 500 to 600 yards, the intervening por- 

 tions being sketched in by the observers. In general the bay has en- 

 croached upon the land between 100 and 500 yards from the shore 

 line shown on the projections furnished by the Coast Survey. The 

 lines of soundings consisted of a parallel series running at approx- 

 imately right angles to the long axis of the bay, connected with the 

 shore by a system of zigzags and traversed where circumstances de- 

 manded by lines running in the required directions. All the larger 



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