biological phenomena towards the improvement of materials, com- 

 ponents, equipments, per sonnel performance, and systems. Some 

 of the important research activities being conducted under this 

 phase of the program are as follows: 



1. Studies of the hydrodynamic characteristics and boundary 

 layer control of marine animals: These studies afford an opportun- 

 ity to obtain basic information which will be useful in the design 

 and construction of new hulls for surface ships and subnnarines. 



2. Research on the mechanisms of propulsion of miarine ani- 

 mals: Data is being obtained to indicate that many marine organ- 

 isms possess propulsive mechanisms which are not only highly 

 efficient but which are silent, presenting no detectable hydrody- 

 namic turbulence. This is a phenomenon of considerable applied 

 interest to the Navy. 



3. Marine animal communications and navigation: It has been 

 established that many kinds of marine animals are able to detect 

 and identify targets and "navigate" towards these targets over 

 great distances with extrenne accuracy. Further, it has been as- 

 certained that many of these forms are able to engage in apparently 

 secure underwater communications exchanges. The Hydrobiology 

 Program is yielding data which will lead to the evolution of new 

 concepts of target identification, long-range underwater navigation, 

 and underwater communications. Ultimately, it is hoped that the 

 fundamental information will be used for the design and develop- 

 ment of mechanical and electronic analogues of direct value to 



the Navy. 



4. Physiological and biochemical evaluation of deep diving 

 abilities of marine animals: Many marine animals including whales, 

 porpoises, seals, as well as a variety of fishes are able to dive 

 very rapidly to relatively great depths and surface just as rapidly 

 without developing the "bends" or other diseases associated with 

 human divers. It is hoped that the information being obtained from 

 this phase of the program will be helpful in developing means for 

 protecting many divers and underwater swimmers against these 

 occupational hazards. 



5. Photosynthetic gas exchangers: One of the important ' 

 problems in the area of submarine habitability is the need for de- 

 veloping innproved means for maintaining a viable atmosphere and 

 getting rid of toxic gases. Plants including algae are able to pro- 

 duce oxygen ajid consume carbon dioxide through the process of 

 photosynthesis. Research is being conducted which is aimed at 

 elucidating these exceedingly complex reactions. In addition, in- 

 vestigations are being conducted on the nutritional requirements, 



the physiology and the biochemistry of algae in an effort to determine 



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