Chapter I — 7 — General Introduction 



analyzed samples of surface sea water near Snow Hill Island in the vicinity 

 of Ross Island. He found 4 to 5 bacteria per ml. of water, the temperature 

 of which was — 1.0° to — 2.0° C. Most of the bacteria were curved or 

 rod-shaped cells. He found bacteria in the intestinal tract of gulls but 

 not in other animals. Growth was obtained on about half of the petri 

 dishes which were exposed to the air for two hours. 



As a member of the Scottish Antarctic Expedition on the Scotia in 

 1902-4, PiRiE (191 2) found bacteria in most samples of surface water near 

 the Orkney Islands. The water temperature was about — 1° C. Most 

 of the bacteria were spirilla or rods. Bacteria were also demonstrated in 

 samples collected from depths of 4000 to 5000 meters. Bacteria were 

 found in most of the marine animals which were examined, but the 

 intestinal contents of certain birds appeared to be sterile. Nitrifying 

 bacteria were not found in either surface or bottom water, but denitri- 

 fiers were common. Plates of nutrient media exposed to the air on the 

 crow's nest were sterile. 



Otto and Neumann (1904) examined several samples of water while 

 crossing the Atlantic Ocean from Europe to South America on a pas- 

 senger ship. They perfected a technique for collecting surface samples 

 while the vessel was moving, but subsurface samples could be collected 

 only when the forward progress of the vessel was stopped. The largest 

 bacterial populations were found in coastal waters near Boulogne, Lisbon, 

 Cape Verde, and Pernambuco. An average of 60 bacteria per ml. were 

 found in the open ocean 5 meters below the surface. Somewhat more 

 were found at 50 to 100 meters, below which the bacterial population de- 

 creased sharply with depth. Bottom deposits harbored a rich microflora. 

 Vibrios and rod-shaped bacteria resembling Proteus vulgaris, Escherichia 

 coli, and Pseudotnonas fluorescens predominated. 



Geat (1909) analyzed water samples from 32 stations on the Planet 

 Expedition in the Atlantic Ocean. Using methods similar to those 

 prescribed by Fischer, Graf found an average of 42 bacteria per ml. 

 of surface water from stations exceeding 120 miles from land and an aver- 

 age of 2000 per ml. near shore. In the harbor of Lisbon, Portugal, he 

 found 54,000 bacteria per ml. 



Drew (1913) demonstrated the occurrence of large numbers of bac- 

 teria in tropical water oflf Andros Island in the Bahamas. They were most 

 abundant in the surface water where several thousand bacteria were found 

 per ml. At 400 meters he found 1760 bacteria per ml., 15 in water from 

 depths of 800 to 1200 meters, and only 2 in water from a depth of 1600 

 meters. He noted the heat sensitivity of marine bacteria and the bac- 

 teriostatic action of metal sampling apparatus, two factors which may 

 account for the low counts obtained by earlier workers. Many of the 

 bacteria were denitrifiers which Drew beheved tended to induce the 

 precipitation of calcium carbonate in sea water. His later contributions 

 on this subject are discussed in Chapter VII. 



In the Mediterranean Sea near the coast of Monaco, Bertel (191 2) 

 noted a progressive decrease in the bacterial population with distance 

 from land in surface water. He found more bacteria in deeper water than 

 at the surface and more bacteria in surface water at night than in the 

 afternoon hours. He attributed the vertical and diurnal distribution of 

 bacteria to the lethal effect of sunlight, a conclusion which has not been 

 confirmed by more recent observations (see page 69). Bertel found a 

 high bacterial count in the Atlantic Ocean between the Azores and Portu- 



