OYSTER BOTTOMS OF MISSISSIPPI SOUND, ALA. 7 



a contmiious indication of the character of the bottom, but the record 

 was made at the regular 15-second intervals observed in sounding. 



The chain, while indicating the absence or the relative abundance 

 of objects on the bottom, gives no information as to whether they 

 are shells or oysters, nor, if the latter, theu' size and condition. To 

 obtain these data it was necessary to supplement the observations 

 already described by others more definite m respect to the desired 

 particulars. Whenever, in the opinion of the ofiicer in cliarge of the 

 sounding boat, such information was requu-ed, a numbered buoy was 

 dropped, the time and number being entered in the sounding book. 

 Another launch, following the soundmg boat, anchored alongside the 

 buoy, and a quantity of the oysters and shells were tonged up, sepa- 

 rated by sizes, and counted. 



This boat at each station made a known number of "grabs" with 

 the oyster tongs, exercising care to clean the bottom of oysters as 

 thoroughly as possible at each grab. In a given depth of water and 

 using the same boat and tongs, an oysterman will cover practically the 

 same area of the bottom at each grab, but, other factors remaming the 

 same, the area of the grab will decrease with an increase in the depth. 



Careful measurements were made and tabulated showing the area 

 per grab covered by tlie tonger employed on the work at each foot of 

 depth of water and for each pah- of tongs and boat used. With these 

 data, and knowmg the number of "grabs," the number of oysters of 

 each size per square yard of bottom was readily obtainable by simple 

 calculation. The followmg example will illustrate the data obtained 

 and the form of the record : 



Department of Commerce and Labor, 

 bureau op fisheries. 



Field record of examinations of oyster beds. 



General locality, Mississippi Soxind, Ala. 

 Local name of oyster ground, Pass des Huitres. 

 Date, December 29, 1910. Time, 1.05 p. m. 

 Angle, C 193-C 194. Buoy No. 2. 



Depth, 3 feet. Bottom, Hard. 



Condition of water, Clear. 

 Density, 1.015. Temperature, 5S° F. 



Current, Stage of tide. Flood. 



Tongman, Bryant. 



No. grabs made, 6. Tongs, 10 feet. 



Total area covered, 2.4 sq. yds. 



No. oysters taken{-l i°-'.«- ^ i^-'^. "^■' '''■ 

 [3 in.-4 in., 33. 4 ni., 0. 



Quantity shells, 0. 



I Spat per square yard, 2.5. 

 Culls per square yard, 45.4. 

 Counts per square yard, 13.7. 



