PROCESSING MARINE PLANT PRODUCTS 243 



Chlorella and Scenedesmus strains, which when dried contained 59 per cent 

 protein; 19 per cent fat; 13 per cent carbohydrate; 3 per cent moisture; 

 and 6 per cent ash, 100 grams could be fed to a man per day. Larger 

 quantities, however, tended to produce gastrointestinal disturbances. 



Animal Food. Meal made from seaweed can be used as an animal food, 

 but the salt content is high. Some manufacturers dissolve out part of the 

 salt, and some also caramelize the sugars to remove the characteristic odor 

 of the meal, which is not appealing to cattle. Up to 10 per cent of seaweed 

 meal can be included in the diet of poultry and up to 20 per cent in the 

 diet of sheep, pigs, and horses. At or below these levels, the meal appar- 

 ently does not affect the odor of the meat. Seaweed meal has also been 

 used in the diet of mink and is said to result in pelts of higher value. 



In the United States, most of the seaweed meal has been produced in 

 California. A product has been manufactured in which the seaweed is 

 combined with fish meal and fish solubles. Seaweed meal also is available 

 imported from such countries as Norway. 



Fertilizer. Although seaweeds are relatively low in nitrogen and phos- 

 phorous, they are high in potassium and the trace elements. (Kelp from 

 Puget Sound, for example, contains about 31 per cent potassium chloride 

 on the dry basis.) With suitable supplementation, they make good ferti- 

 lizer. Macpherson and Young ^ found in the seaweed of the ^Maritime 

 Provinces a nitrogen content of 2.4 per cent and a phosphorous content 

 one-tenth that high on the dry basis. The moisture content was 83 per 

 cent. In contrast to many fertilizers, seaweeds are free of weed seeds and 

 spores of crop diseases. 



Chemicals. An astonishing variety of chemicals can be produced from 

 seaweed — and in quantity. It has been estimated, for example, that the 

 United States alone could produce 6 million tons of potassium chloride 

 and 19 thousand tons of iodine a year from seaweed if necessary. These 

 materials now are obtained more cheaply from other sources, but during 

 World War I, our requirements for them were met by the production 

 from seaweed in California. Also produced at that time were a number 

 of organic solvents, including acetone, ethyl acetate, ethyl propionate, 

 and ethyl butyrate. 



In attempting to produce chemicals from our seaweed resources, pio- 

 neer investors lost large sums of money. Eventually, however, they were 

 able to establish a stable industry in the production of phycocolloids. 



Phycocoltoids from Seaweeds. The term ''phyco" is a Greek word mean- 

 ing seaweed, so phycocolloids are simply seaweed colloids. Colloids are 

 materials, such as gelatin, pectin, and starch, that have the property of 

 forming gels. Although there are a number of phycocolloids that can be 

 produced from seaweeds, only three — agar, algin, and carrageenin — are 



