COMMERCIAL VALUE OF KELP-BEDS 27 



SESSIONAL PAPER No. 38a 



the north side of Hope island, oiT the north coast of Vancouver island, Nereocijstis 

 liiiTceana, Macrocystis pyrifera, Alaria (a second species), Egregia menziesii, Cyma- 

 thcere triplicata, and Hedopliyllum. 



Of all these, only Nereocystis lutkeana and Macrocystis pyrifera are of economic 

 importance. The other Laminaria are not present in large beds. The Fucacece, while 

 abundant, could only be collected by hand, and conditions of labour along the Pacific 

 coast therefore negative any idea of their utilization. Furthermore, their potash 

 content is much smaller than that of the two kelps. These, from their nature, can 

 be harvested by mechanical means, and hence at a much smaller cost. 



Nereocystis liitke^ana, commonly called bull-kelp, or simply kelp, consists of a 

 long stalk or stipe, much branched below into the " holdfast " attaching it to a small 

 rock or rock-crevice several fathoms below the sea-surface, and distended above into 

 a hollow bladder, the " pneumatocyst," containing air. To this are attached numerous 

 long fronds which are kept near the surface of the water by means of this float. 

 Nereocystis is found growing at depths varying from 1 or 2 to 10 or more fathoms. 

 Most of the Nereocystis that I have examined has been growing at depths of from 4 

 to 6 fathoms (24 to 36 feet). The length of the plant varies considerably. The 

 longest plant that I measured was 63 feet in length. This was obtained near Haro 

 strait, just north of the Puget Sound region. In the latter, Rigg states that he found 

 no specimens over 70 feet in length^, although elsewhere much greater lengths have 

 been recorded. Much larger plants are also met with in British Columbia waters. 

 Ml*. A. Lucas, fishery overseer at Alert bay, informs me that he has obtained a plant 

 on Nawhitti bar, off the North coast of Vancouver island, measuring 111 feet in 

 length. 



Nereocystis UltJceana is found more or less extensively throughout British Colum- 

 bian waters. 



Macrocystis pyrifera is, according to Setchell, known as " long bladder kelp."^ 

 I have found in use the more descriptive terms " sea-ivy " and " flag-weed." The 

 plant consists of a holdfast of many whorls, from which extend upward usually 

 numerous stipes, each of which carries at regular intervals large ivy-leaf-^haped 

 fronds, joined to the stipe through a buoying bladder. The length of the plant is 

 va-riable. Off the Californian coast plants 1-50 feet in length have been met with. 

 Eigg states that 50 feet is the common length in the Puget Sound region. I have 

 found plants 40 to 50 feet in length in Barkley sound (west coast of Vancouver 

 island) and 30 feet or less off the north coast of Vancouver island and off Banks 

 island. A diminution of mean temperature may determine this diminution of length. 



Macrocystis pyrifera has been reported off Victoria and Port Renfrew. I have 

 found it in Barkley sovmd, along the north coast of Vancouver island, off Banks 

 island, and in Qlawdzeet anchorage, Stephen island, so that it is evident that it is 

 present along the whole coast of British Columbia. This was to be expected, since, 

 while common farther south, it is also not uncommonly met with in Alaskan waters. 

 It is not present in the inner coastal waters of British Columbia, from Ten-mile 

 point, near Victoria, to Port McNeill. Its absence in these waters must be attributed 

 to their lessened salinity. 



CONDITIONS AFFECTING THE GROWTH OF " NEREOCYSTIS " AND OF " MACROCYSTIS.." 



The factors determining the growth of Nereocystis liitheana and Macrocystis 

 pyrifera are the same : — 



(1) A suitable rocky surface of attachment. 



(2) A marked movement of the v/ater containing the plant. 



(3) A suitable salinity. _ ' 



(4) Not too high a temperature. 



1 "Fertilizer Resources of the United States." Senate Document 190, 1912, p. 180. 



2 Ihid., p. 159. 



