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BULLETIN OF THE BUREAU OF FISHERIES 
SURVEY OF OYSTER BOTTOMS IN AREAS AFFECTED BY OIL 
WELL POLLUTION 1934 
By Robert 0. Smith 
METHODS 
The survey vessel was a standard oyster and shrimp lugger, 36 feet in length, with 
24 inches draft, and a maximum speed of 10 miles per hour. The vessel had been 
reconstructed to carry scientific equipment and to provide living accommodations 
for 4 persons. 
A total of 423 stations approximately half a mile apart were made. At each 
station a sample of bottom water was taken for specific gravity; the depth, bottom 
temperature, and character of the bottom were observed. Occasional surface samples 
were taken for comparison. An average of 3 minutes was required for these observa- 
tions at each station. The water samples were taken with a Galtsoff sampler, using 
a 1-liter Wolff bottle. Depths were measured with a 16-foot sounding pole marked 
in conformity with Coast and Geodetic Survey practice. Bottom temperatures were 
read from a Bureau of Fisheries surface thermometer in brass cup case. Bottom 
water samples at each station were placed in citrate of magnesia bottles and the 
specific gravities of all were measured by hydrometer at the end of the day’s run. 
Conversion of specific gravity to salinity was made from Knudsen’s table. 
The stage of the tide throughout the hydrographic work is given as at Wine Island 
unless otherwise stated. 
All locations refer to the Coast and Geodetic Survey progress sketch of Terre- 
bonne and Timbalier Bays prepared February 1934, under the direction of Lf. W. D. 
Patterson, chief of party. Prior to this work no accurate chart of the region existed. 
Without this chart, and the signals erected in preparing it, this survey could not have 
been made, for there are no natural landmarks, no trees, and only occasional human 
habitation in the form of fishing camps. 
GENERAL CONDITIONS 
The area covered by the survey extended from Timbalier Bay on the east to 
Pelican Lake on the west, including approximately 400 square miles (fig. 1). The 
examination of beds and hydrographic survey began February 19, 1934, and continued 
to March 15. Two days, March 27 and 28, were spent in Barataria Bay and Lake 
Washington. 
The bottom over this entire area is exceedingly level. There are very few gullies 
or reefs except where islands are in the process of being broken down. The bottom, 
composed of soft black mud and mixed with broken shell, was devoid of vegetation 
at the time of the survey. On account of the shallowness of the water, rarely over 
6 feet, moderate winds churn the bays from top to bottom, so that the water is seldom 
clear except at the passes during flood tide. The oyster reefs are limited to sections 
where the bottom is comparatively firm. This condition occurs usually only about 
the margin of the bays or around islands. 
The mean range of tide at Wine Island, near the center of the area, is 1.3 feet. 
Usually there is only 1 high and 1 low tide daily. However, the actual change in 
