The activities of these marine organisms could have many serious consequences. 

 For example, if lumber, manila and cotton ropes, and other materials which are 

 susceptible to destruction by marine borers and other organisms are used, fail- 

 ure of these elements could result in a hazardous situation. 



Biological growths in critical areas of the structure could cause problems 

 leading to reduction in the useful life of the established structure even though 

 the structural elements were not damaged. For example, marine growths on 

 viewports of the structure and on the front transparent housing of television 

 and still cameras could interfere with operations and experiments. As a fur- 

 ther example, biological growths in the intake and exhaust pipes for seawater 

 would detrimentally affect the performance of such systems. 



The presence of planktonicforaminifera and other biological inhabitants 

 of the water column interferes with sound and light transmission. The presence 

 or absence of these inhabitants greatly affects visibility, expecially in deep 

 waters where artificial lights are required. Sound transmission is also affected 

 by these water-borne plants and animals. The deep scattering layer which 

 occasionally appears on echograms from surface-conducted bathy metric sur- 

 veys is an example of this effect. 



Marine bacteria of both the aerobic and anaerobic types when present 

 in the environment of the structure could detrimentally affect the structure 

 and component parts. Although the bacteria are small, in large quantities 

 they can create wide-spread damage as the following examples illustrate. 

 Sulfate-reducing bacteria in an anaerobic environment produce hydrogen 

 sulfide, known to be a corrosion agent. Aerobic bacteria cause organic mate- 

 rial to decompose. Bacteria are also the source of primary films, which initiate 

 fouling on materials. 



Thus, the measurement of biological parameters in site survey operations 

 is necessary to make an adequate assessment of the suitability of a site with 

 respect to biological fouling and other effects. 



Surface Phenomena 



Data on surface phenomena, including climatological characteristics, 

 sea states, surface currents, and tides are required for evaluation of specific 

 sites. Since surface support will be used in the installation, maintenance, 

 resupply, and possibly emergency rescue associated with the bottom structure, 

 the effects of these surface phenomena must be known. 



If a surface power source is used, surface effects will be highly 

 significant. With these measured data, the proper anchor configuration or 

 dynamic positioning technique could be designed. These data would also 

 aid in designing a specialized platform for surface-support applications. 



