6 OYSTEK BOTTOMS OF MISSISSIPPI SOUND, ALA. 



accurate determination of the location, extent, and condition of the 

 natural oyster beds and the examination of the barren bottoms in 

 relation to their adaptability to oyster culture. 



No o^^ster survey of the region covered by this report had been 

 made previously, although the important beds adjacent to Grant's 

 Pass had been the subject of reconnoissance in 1894." 



METHODS OF THE SURVEY. 



The methods employed were those pursued in former surveys of 

 like character and are explamed in detail in a description of the beds 

 of the James River,^ from which some of the following is repeated: 



A '^boat sheet" was prepared, on which were accurately platted 

 the positions, as determined by triangulation, of lighthouses, build- 

 ings, tripods, etc., used as shore signals. These data were furnished 

 by the United States Coast and Geodetic Survey. 



The oyster beds were discovered by soundings with a lead line, 

 but principally by means of a length of chain dragged over the bot- 

 tom at the end of a copper wire running from the sounding boat. 

 The wire was wound on a reel and its unwound length was adjusted 

 to the depth of water and the speed of the launch, so that the chain 

 was always on the bottom. Wlienever the chain touched a shell or 

 an oyster the shock or vibration was transmitted up the mre to the 

 hand of a man whose sole duty it was to give heed to such signals 

 and report them to the recorder. 



The launches from which the soundings were made were run at a 

 speed of between 3 and 4 miles per hour. At mtervals of three 

 minutes — in some cases two minutes — the position of the boat was 

 determined by two simultaneous sextant observations of the angles 

 between a set of three signals, the middle one of which was common 

 to the two angles, the position being immediately platted on the 

 boat sheet. At regular intervals of 15 seconds, as measured by a 

 clock under the observation of the recorder, the leadsman made a 

 sounding and reported to the recorder the depth of water and the 

 character of the bottom, immediately after which the man at the wire 

 reported the character of the chain mdications since the last sound- 

 ing — that is, whether they showed barren bottom or dense, scat- 

 tering, or very scattering growtlis of oysters. 



With the boat runnmg at 3 miles per hour the soundmgs were 

 between 80 and 90 feet apart, and, as the speed of the boat was 

 uniform, the location of each was determmable within a yard or two 

 by dividing the platted distance between the positions determmed by 

 the sextant by the number of soundings. The chain, of course, gave 



a Report of a reconnoissance of the oyster beds of Mobile Bay and Mississippi Sound, Ala., bj^ Homer P. 

 Ritter, assistant, United States Coast and Geodetic Survey. Published in Bulletin United States Fish 

 Commission, vol. XV, 1895, p. 325-329, pi. 56-63. 



b Moore, H. F.: Condition and extent of the oyster beds of James River, Va. Bureau of Fisheries Doc- 

 ument No. 729. 



