32 



the effectiveness of the curtain in reducing currents. Storms during 

 the month, however, began tearing the curtain at its points of 

 support and, by the end of the month, most of the curtain was lost. 

 The effect of the loss of the curtain combined with intense storm 

 induced currents and waves as well as resulting motions of the 

 farm, was the abrasion of many of the plants against the test farm 

 structure. The intensity of the storms began increasing during 

 January, causing further attrition such that by month's end, the 

 useful population was reduced to 18 plants. By the first week of 

 February, there were no viable transplants left on the farm. 



During May of this year, extensive occurrence of new plants was 

 observed on the farm. The new plants resulted from spores re- 

 leased by the adult transplants. Measurements of growth and nu- 

 trient uptake by those plants which are being supplied with artifi- 

 cially upwelled water, indicate that they are thriving in the test 

 farm environment. This occurrence is a major milestone in demon- 

 strating reproduction and development of juvenile plants on an 

 open ocean structure. The study of these plants has been incorpo- 

 rated into the test program. 



Action will soon be underway to select a stronger curtain materi- 

 al and to change the curtain assembly design to provide additional 

 protection for the plants. It is planned that after the redesigned 

 curtain has been installed, the farm will be replanted with as 

 healthy plants as can be obtained. These will be taken directly 

 from natural beds to the test farm. 



Thus, in sum, first year deployment of the test farm has re- 

 vealed: 



One, the test farm upwelling system has performed as designed; 

 providing 9,000 gallons per minute of water containing from 25 to 

 32 microgram-atoms per liter of nitrogen in the form of nitrates 

 and nitrites. 



Two, the test farm's mechanical structure has performed as de- 

 signed, and the integrity of the test farm's mechanical structure 

 continues to be sound. 



Three, the curtain device used to reduce or deflect currents in 

 the immediate vicinity of the plants and thereby retain nutrients 

 around them, works, but the curtain design must be modified to 

 increase its survivability and to protect the plants from abrasion 

 on the structure during periods of high currents. 



In order to determine overall system economics, integration of 

 kelp production research with development of biomass conversion 

 technology has continued. In the past year, work in the gas genera- 

 tion area has brought about the following achievements: 



One, digestion of kelp is providing gas yields equal to or greater 

 than the other types of biomass. 



Two, digestion has been conducted at ambient temperature with 

 marine derived inocula, at a liter scale, with no loss in gas produc- 

 tion. 



Third, digestion has been conducted at salt concentrations of up 

 to 4 percent — seawater is 3 percent — at a 10-liter scale using 

 sewage derived inocula by feeding undiluted kelp directly to diges- 

 tors. 



These findings have significant implications for the system eco- 

 nomics. The higher gas yields and lower digestor temperatures 



