The present study was undertaken to Investigate, analyze, and evaluate the 

 effects of marine organisms of the archlbenthic and abyssal zones on various types 

 of engineering materials such as elastomers, plastics, metals, portland-cement, 

 concrete, and electrical v/ire conductors. The study places particular emphasis 

 upon the biological deterioration of engineering materials exposed in the deep-ocean 

 environment as well as in the marine sediments. 



In the following pages a preliminary analysis of environmental variables is 

 summarized, the results of a literature survey of the problem are presented, and a 

 proposed field and laboratory study to accumulate further data on the effects of 

 marine organisms on engineering materials is submitted. 



PHYSICAL PROPERTIES OF SEA WATER 



The environmental variables which are of Immediate interest to marine 

 biologists and oceanographers include salinity, temperature, density, viscosity, 

 pressure, light penetration, suspended organic matter, dissolved gases, and 

 hydrogen-ion concentration, ^i-^i^ A brief summary for each of these variables 

 follows. 



Salinity 



The salt concentration of sea water Is known as salinity and Is expressed as 

 grams of salts per kilogram of sea water (parts per mi lie, o/oo). The salinity In 

 the ocean Is generally between 33 and 37 o/oo. Because the salinity range In the 

 open oceans is rather small, an average value of 35 o/oo is used. 



Temperature 



The average surface temperatures for all the oceans range from about 27 C 

 near the equator to (-) 1 C In the arctic and antarctic regions. However, with 

 Increasing depth not only does the temperature drop, but the seasonal variations 

 become negligible below depths of about 600 feet. The temperature at 600 feet 

 is about 20 C, at 4,000 feet it Is about 5 C, and below this depth the temperature 

 falls to a minimal value of 1 to 2 C in the abyssal regions. 



Specific Gravity 



The specific gravity of sea water Is dependent upon salinity, temperature, and 

 pressure. At atmospheric pressure and C the specific gravity of sea water of average 

 salinity 35 o/oo is about 1.028, and at 10 C it is about 1.027. 



