45 



hoses or lines for as long as an hour and down as deep as 300 feet. Captain 

 Jacques Cousteau has been active in developing this type of gear and in encour- 

 aging its use in ecological studies. In an investigation of the fauna associated 

 with kelp, being conducted at Scripps, most of the observations are made under 

 water by a scientist equipped with a diving unit.* The underwater camera is also 

 an essential tool in such investigations. 



NEEDED BIOLXDGICAL INSTRUMENTATION 



What is needed in biological instrumentation? I have already touched 

 upon, in the text, some of the instrumentation needed for locating, identifying 

 and sampling the more actively swimming organisms. Electrical fishing, which 

 seems to offer considerable promise, is still in the developmental stage. In 

 the same category is the possible use of television for studying the distribution 

 and abundance of pelagic and bottom organisms. Gear is needed for effective 

 sampling of the larger organisms, fish and squid, in the mid-depths of the ocean. 

 Perhaps larger trawls of the type devised by Isaacs and Kidd may offer a solu- 

 tion to this problem. A challenging problem is some means of identifying the 

 deeper schools of fish recorded on echo-sounding instruments. Eventually, it 

 may be possible to identify schools of fish from the type of pattern that is re- 

 corded on echo-sounding instruments, but in order to establish such a relation- 

 ship it is first necessary to sample, or, by some other means such as under- 

 water photography, identify the schooling organisms. 



One of the pressing needs in the field of plankton research is for hi-speed 

 samplers capable of taking deep tows. A limitation on all hi-speed gear devel- 

 oped to date is the shallowness of the layer that can be sampled with the gear. 

 'The Hardy plankton recorder is designed to tow at 10 meters depth. The Isaacs 

 hi-speed samplers cannot be gotten much deepe'r than 50 to 60 meters when used 

 with a single depressor on i" cable. Even by using special wire and greater 

 depressing force, it is unlikely that the sampler could be gotten much deeper 

 than 100 to 150 meters. This is not deep enough to sample the deep scattering 

 layer, for instance. The development of self-propelled units, entirely freed 

 from dependence on towing cable, may be a possibility. 



Another need is instrumentation for studying patchiness in the distribu- 

 tion of plankton. The only sampler now available that can be effectively used in 

 studying this feature is the Hardy plankton recorder. This instrument gives a 

 record at one depth only, hence is useful for studying variation in the horizon- 

 tal component of distribution, but not in the vertical. To include the vertical 

 component it would be necessary to have a type of sampler that can be used in 

 series. It should be possible to construct a hi-speed sampler having a number 

 of small nets which successively could be moved into position during a haul. 

 Several of these samplers used in series, with their operation synchoronized, 

 would supply the type of sampler needed for studying irregularities in the hori- 

 zontal and vertical distribution of plankton. 



A development that is being given considerable thought by workers at 

 Scripps is an instrument that will take a sample of the bottom mud and the water 

 immediately above, without disturbing the mud-water interface. 



* - The Aqualung now is being widely used by scientists in all parts of the 

 world. The interesting book by Captain J.Y. Cousteau (with Frederick Dumas), 

 "The Silent World", has drawn the attention of the general public to the adventure 

 of undersea exploration with the Aqualung. George Hetzel, (1953) of Scripps In- 

 stitution of Oceanography, has put out a useful repair manual for the Aqualung. 



