PRELIMINARY OFEF SITE SELECTION 



Before specific site selections are made, certain areas can be omitted because their 

 environmental characteristics are completely outside the preliminary selection criteria. The 

 following discussion will tentatively support or reject certain areas as potential farm sites for 

 Phase 1 ; additionally, some discussion of site potentials for future phases will be given. 



BIOLOGICAL CRITERIA 



Temperature 



Utihzing 20°C as the temperature maximum for Macrocystis tolerance and Fig. 1 1 as 

 a guide, it is apparent that south of about 3 1°N, cooling by upwelling will be required. The 

 further south the site is located, the greater is the upwelling required to lower the ambient 

 temperature to 20°C, except for the equatorial upwelling region where ambient surface tem- 

 peratures are lower, thus reducing the requirement for upwelled water. From Figs. 1 and 1 1 

 plus Appendices B and C, it is apparent that areas 1 1 and 12 require no cooling from upwell- 

 ing (the need for nutrients in these areas may, of course, impose requirements for upwelling). 

 Areas 1-9 are marginal and may require slight cooling during the late summer. Areas 10, 15, 

 and 18 would require some cooling during the summer months. Area 13 would require 2 to 

 3 degrees cooling during summer and fall. Assuming that the upwelled water was from 200 

 meters (13°C) and completely mixed, then approximately 33 percent upwelled water would 

 be required in the surface layer to lower its ambient temperature to 20°C. Off Hawaii (areas 

 14 and 16), approximately 50 percent of the surface water would have to be upwelled from 

 200 meters to meet the temperature requirement. Also, in areas 17 and 19 in the tropical 

 eastern Pacific north of the equator, the surface waters would have to be mixed with approx- 

 imately 50-percent upwelled water from 200 meters to lower ambient temperatures to 20°C. 

 In area 20, the winter and spring seasons are the warmest (25°C), thus requiring approxi- 

 mately 40-percent upwelled water mixed with ambient surface water to lower the tempera- 

 ture to 20°C. 



The 20°C temperature limitation has not been conclusively demonstrated, and the 

 actual hmiting temperature may be significantly higher, thus possibly requiring less upwelling 

 for cooling purposes. If, however, 20°C is assumed to be limiting, then north of 30°N there 

 appears to be httle or no problem from upper temperature limitations whereas south to 

 about 25°N some cooUng will be required. Off Hawaii and between 25°N and the equator, 

 surface temperatures may be hmiting unless enough deep water (200-meter) can be brought 

 to the surface to produce a 50 percent deep/50 percent surface water mixture. 



Nutrients 



Macrocystis nitrate requirements are tentatively placed at 3 to 5 jug-at/liter minimum, 

 and 10-15 Mg-at/liter optimal. The only areas where the required nitrate concentrations are 

 observed at the surface are the near-coastal zones during the upwelling seasons and in the 



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