Figure 6. The sea floor south of Capri at 1000 meters is pock-marked with small hole 

 sculpturings indicating the presence or recent presence of animols. 



mounds, and 



of ambient sunlight to depths of 350 meters. The twilight or "dusk" light condition be- 

 tween 50 and 350 meters interferes with the visual observations by reducing the effec- 

 tiveness of the mercury vapor light beam, yet the ambient light inadequately illuminates 

 the suspended materials. 



The water column was found to contain suspended matter from the surface to the 

 sea floor. Within the area of greatest illumination, the water above the thermocline, it 

 was difficult to discern any animals except some large siphonophores, salps, and 

 medusae. Below the thermocline, which usually occurred at 25 to 40 meters during the 

 diving season, the amount of suspended material appeared to increase. At the maxi- 

 mum level of sunlight as determined by the human eye, 500 meters, there is a marked 

 increase in the abundance of suspended material and bioluminescence. 



Below 350 meters, the artificial light becomes quite effective and it is possible to ap- 

 preciate the voluminous amount of existing "snow." The descending bathyscaph pro- 

 duces the illusion of snow falling upwards. The "snow" appeared to lack individual 

 particle movement, suggesting that much of the material might be inanimate. However, 

 when the TRIESTE was stationary on the sea floor, it was noted that many organisms 

 allow themselves to be carried by the prevailing currents and that they only occasion- 

 ally resort to active swimming. 



10 



