32 



DEPARTMENT OF THE NATAL SERVICE 



6 GEORGE V, A. 1916 



gible. (The observations were made on August 19.) The absence of kelp in Howe 

 sound is traceable to several causes, each probably in itself sufficient. The shore is 

 sheer, a depth of 60 fathoms or more being reached a few feet out. The rocks are of 

 carboniferous limestone, affording no hold fo-r kelp, even were there any ridges at a 

 suitable depth below the surface. The whole of the water of the sound is brackish, a 

 large amount of fresh water being contributed by the Squamish river, flowing into 

 the head of the sound. Density measurements taken within 3 miles of the head of 

 the sound showed fresh water. Measurements 23 miles farther out (just outside the 

 sound itself, in the strait of Georgia) showed a density of only 1-008. It may be 

 pointed out here that since kelp grows near the surface, and since the greater part of 

 the plant remains within 2 or 3 feet of the surface, it- must be particularly subject to 

 the influence of the surface water, so that measurements of the density of this give 

 a clue to the salinity of the sea-water actually affecting the plants. 



The conditions in Burrard inlet are somewhat similar to those in Howe sound, 

 but the amount of fresh water flowing into the inlet is less, and the mean density 

 value of the surface water higher. The combined coast-line of Howe sound and 

 Burrard inlet is about 200 miles. The situation of this district can be seen by refer- 

 ence to Charts I and II. Off the extensive sand flats at the mouth of the Fraser river 

 (see Chart II) no kelp is to be expected. I have not examined these flats myself, but 

 have been informed by numerous persons that no kelp exists along this strip of coast. 



Howe sound is typical of most of the large inlets farther north, both as regards 

 the brackishne'ss of the water, and the sheerness of the shores. I am informed thp.t 

 no kelp exists in any of them, except perhaps along the islands at their mouths. 

 District B can, therefore, be taken as representative of a very considerable amount of 

 coast-line. 



District C. — The district north of Vancouver island is much richer in kelp than 

 District A. The part surveyed is shown in Chart III, and the work was carried out on 

 July 23 and 26, inclusive. An attempt was made to see the kelp on Nawhitti bar, to 

 the west of the portion charted. There are vast beds here for more than 10 miles, 

 indeed most of the way to cape Scott, and the kelp grows to a much greater size than 

 on the less exposed portion actually seen. The weather conditions were unfavourable, 

 and I was unable to see this region. In order to chart this mass of kelp properly it 

 may be necessary to stay a week or longer in Bull harbour, Hope island, and seize a 

 favourable combination of calm weather and slack low water. It should be noted that 

 in order to survey many of the beds properly it is necessary to see them under these 

 conditions; this materially hinders rapid work. Rough water hides the kelp con- 

 siderably and prevents an accurate estimate of its extent. The kelp grows most 

 luxuriantly in a " tide-rip," and this when in action drags it under, and may almost 

 . completely submerge large beds. 



In order to estimate the weight of kelp available in this district sample plants 

 were taken from a very large patch north of Haddington island with the following 

 results : — 



