of the Fishery Board for Scotland. 



xvii 



for the hatchery are obtained, was, as usual, reduced in number in 

 the course of the summer, and, in the circumstances that existed, 

 it was not possible to renew this stock with living fish from the sea. 

 Another circumstance that interfered with the spawning of the fishes 

 was that the spawners had to be confined for about six weeks 

 in a small reservoir tank while the reconstruction of the filter- 

 chamber for the large tank was in progress. In consequence of 

 the diminished stock and of the circumstances just described, the 

 number of fertilised eggs obtained from the pond was much smaller 

 than in former years, and did not exceed half a million. The fry 

 obtained from these, estimated to number about 450,000, were put 

 out in the sea in the neighbourhood of the Hatchery. 



Since the hatching of the plaice was begun at the Bay of Nigg, the 

 estimated number of the eggs which have been dealt with amounts to 

 about 438,201,000, and approximately 343,694,000 fry of the plaice 

 have been put into the sea. The results of this experiment are 

 described in the Twenty- Sixth Annual Report. 



During last year, the steam-pumps used for pumping the water 

 in connection with the Hatchery and Laboratory were replaced by 

 electric pumps, which were fitted up under the direction of Mr. J. A. 

 Bell, the Electrical Engineer for the Corporation of Aberdeen. 



The Investigations on the Herring Fishery in Lochfyne. 



The investigations on the Lochfyne herring fishery, which have 

 been described in previous Reports, were continued in 1915, so far as 

 the means at disposal allowed. The. statistics show that the yield 

 from this once important fishing still continues at a low level ; but it is 

 encouraging that the quantity of herrings taken last year was con- 

 siderably greater than in any of the previous three years, amounting 

 to 13,399 cwts., or 3828 crans, as compared with 919 crans in 1914, 

 3056 crans in 1913, and 2192 crans in 1912. In September, most of 

 the fish were caught in Kilbrennan Sound, but at the end of that month 

 and during October and November, they were taken at the mouth of 

 the Loch. A small quantity of herrings of very good quality were 

 caught near Inveraray at the end of September. The following shows 

 the monthly catch (in cwts.) last year : — 



January . 



Februarv 



March 



April 



May 



June 



378 



45 

 460 



July. 



August 

 September 

 October 

 November . 

 December 



539 

 214 

 223 

 4033 

 6209 

 1298 



Total— 13.399 cwts. 



Nevertheless, the quantity taken was very small compared with 

 former years. 



Fluctuations in the herring fishery, especially in fjords or arms of 

 the sea, are of no infrequent occurrence on the coasts of other countries, 

 and have been attributed to various causes, such as changes in the 

 physical conditions of the water, or in the quantity or kind of the 

 b 



