marine biology 



The Mediterranean area is recognized as being biologically unproductive relative to 

 the great oceans and should, therefore, be only sparsely populated with deep-sea or- 

 ganisms. With such knowledge at hand, it was a pleasant surprise to find during the 

 dives that the deep waters of the Mediterranean are not devoid of animals and the pop- 

 ulation and variety of deep-sea organisms appear to be fairly large. 



Time on the bottom was restricted on many dives by the nature of the research being 

 conducted. Despite this shortcoming, marine life such as fishes, was noted on nearly 

 every dive (fig. 4 and 5). Alterations of the sea-floor surface remained as evidence of 

 recent animal presence (fig. 6). The bathyscaph provided an opportunity to observe 

 directly the animals and their motions and the materials that exist in the deep sea. 



The need for a better understanding about the sound-scattering characteristics of bio- 

 logical populations and how they interfere with acoustic detection devices prompted 

 the expenditure of considerable efFort toward determining the distribution and quantities 

 of biological material in the water column. 



The distribution of organisms in the water column was determined only qualitatively. 

 Below the depth where the ambient light, from the sun and sky was sufficient, the obser- 

 vations were assisted by three mercury vapor lamps and one small tungsten lamp. Two 

 of the mercury lights were located in front of the sphere and one behind. These lamps 

 provided excellent illumination for the detection of animals and particulate matter in 

 midwater or on the sea floor. Intermittent use of the lamps in midwater probably did 

 little to frighten marine life away from the bathyscaph. Phototropic response of the or- 

 ganisms was studied very carefully while the TRIESTE was stationary on the sea floor. 



It became obvious on the first dive that a volume of water follows closely behind the 

 ascending bathyscaph, thereby disrupting the continuity of the water mass and its con- 

 stituents. From within the sphere, therefore, the most reliable quantitative estimate of 

 suspended materials can be made only on the descent. Another disturbing factor en- 

 countered in attempting to determine the quantity of planktonic material is the presence 



Figure 4. Shadow of a 6-foot eel at 1090 meters depth, south Figure 5. Shadow of a 6-foot eel ot 1090 meters depth, south 

 of the Isle of Capri. of the Isle of Copri (same individual as in figure 4). Debris, 



probably a piece of wood, is seen just beneath the toil. Open 

 wire bait-can at upper center was filled with cheese-bait to 

 attract creatures such as this eel. 



