UTILIZATION OF THE FISH WASTE OF THE PACIFIC OCEAX. 53 



cannery waste into fertilizer, and adequate supplies of these are 

 found near certain of the centers of the salmon- canning industry. 

 It originally was supposed that the rendering of the cannery waste 

 could be made to serve as an auxiliary operation to the treatment of 

 kelp. After investigation it appears more probable that it would 

 be found necessary to make the curing of kelp supplementary to the 

 rendering of fish waste, since the apparatus required for the latter 

 is much more elaborate than that for the former. 



The term " kelp," formerly applied to the ashes of seaweeds, now 

 has come to mean any of the brown marine algse. In general use its 

 meaning has become restricted to the large and conspicuous sea algse 

 of the Pacific coast. The so-called giant kelps of the Pacific coast 

 may be defined as four species of the marine alga?, whose botanical 

 names are Pelagophycus porra, Alaria fistulosa, Nereocystis luei- 

 keana, and Macrocystis pyrifera, named in the reverse order of their 

 present economic importance. Only two of these, the latter two, at 

 present should be considered in a fertilizer connection, as of the 

 former two, the Pelagophycus porra occurs in too small quantities 

 to be important, though it carries a very high proportion of valu- 

 able fertilizer ingredients, and the Alaria fistulosa is too low in 

 potassium to merit treatment where the other kelps are available in 

 sufficient quantities. 



The Nereocystis is an annual whose seasonal growth attains an 

 average of 50 feet. The rapid growth necessary to reach such a size 

 in a growing season denotes an abundant suppky of the elements or 

 compounds which enter into the plants' metabolism, and this, in turn, 

 indicates a large and constantly changing volume of the medium in 

 which it grows. Thus it is found in localities of heavy surf or strong 

 tideways. To maintain itself in position under these conditions it 

 must attach itself firmly to the bottom. Therefore a rocky bottom is 

 essential to the establishment of groves of the plants. To attach 

 itself, the plant develops a "holdfast," a rootlike growth which 

 tends to grow around and grasp the objects with which it comes in 

 contact, thus anchoring the plant. Extending upward from the 

 holdfast is the stipe, a long, slender stem, cordlike and tough, which 

 reaches almost to the surface of the water. Toward its upper end 

 it gradually enlarges, becoming hollow, and culminates in a hol- 

 low bulb. This portion, being air filled, serves to float the plant, and 

 is called the pneumatocyst. The plant thus is lifted and held in 

 the sunlight. From the top of the pneumatocyst develop two tufts 

 or bunches of long, ribbonlike leaves, called fronds, which grow 10 

 or 15 feet in length and trail out in the tidal currents. The most in- 

 teresting characteristic of the plant, and a characteristic that dis- 

 tinguishes it from the other important kelp, the Macrocystis, is that 

 almost the entire plant, on the basis of weight, lies on or at the 



