Figure 5. Sterile syringe is used to collect seawater sample through countersunk 

 hole in rubber stopper for bacteriological analysis. 



Bacteriological Tests. The seawater samples from inside the recovered 

 test chambers covered with membrane filters were obtained aseptically by 

 inserting the needle of a sterile hypodermic syringe through a countersunl< 

 hole in the rubber stopper, the exposed part of which was cleaned, washed, 

 and sterilized with ethyl alcohol (Figure 5). A sterilized ZoBell bacteriological 

 water sampler was used to collect seawater samples from 10 feet below the 

 surface (at high tide) off the end of Point Mugu Pier for bacteriological analyses. 



In the laboratory, the collected water samples were filtered through a 

 0.45-micron membrane filter. Upon completion of the filtration, the filters 

 were placed on the surface of a nutrient agar medium to culture the viable 

 microorganisms caught on their surfaces. The nutrient medium was developed 

 by Morita and ZoBell for growing marine bacteria. ^^ After several days of 

 incubation, the small bacterial colonies growing on the surface of the filter 

 papers were examined and counted under a stereoscopic microscope. 



11 



