THE NAVY OCEAN SCIENCE PROGRAM 



41 



Underwater television monitor observation of a school of 

 margate assembled in the eeirly morning hours 



cetaceans in the oceans has been tested and is to be used to 

 investigate the behaviorial patterns and reactions of porpoises. 



Studies are being made that combine acoustics and optics. 

 Plankton, that is, small floating or feebly swimming animals 

 that occur in dense clouds, scatter both sound and light and have 

 an eflfect like fog on a display system. Plankton, other small 

 organisms and accompanying predatory fish appear to be the 

 principal sound scatterers. Their target strength and resonant 

 frequencies are investigated, as well as their distribution and 

 variation with season. Many species spend daylight hours at 

 depths of a few hundred fathoms and disperse toward the sur- 

 face at night, but the full particulars of their behavior are not 

 known. All of these characteristics limit the effectiveness of 

 sonar operations. 



As light scatterers, plankton reduce the range of vision for 

 photography underwater. Hence, they hamper construction and 

 salvage operations where divers, photography, or closed-circuit 

 television are used. Some plankton present the Navy with special 



