of the Fishery Board for Scotland. 



lix 



PART III. 



SCIENTIFIC INVESTIGATIONS. 



During the year 1911 the scientific investigations in connection 

 with the sea fisheries have been carried on under the supervision of 

 Dr. T. Wemyss Fulton, the Scientific Superintendent, as authorised by 

 the Board, on the same general lines as in previous years. Most of 

 the research work has been conducted at the Marine Laboratory at the 

 Bay of Nigg, Aberdeen, and other inquiries in relation to the herring 

 and the herring fishery have been made in Lochfyne, in continuation 

 of the observations of preceding years, and also in the Moray Firth 

 with reference to the closing of the waters there to the operations of 

 trawlers. The special statistics of the catches of the line-boats in the 

 Moray Firth have been collected monthly through the Fishery Officers 

 as before, and the old trawling stations of the s.s. " Garland " have been 

 periodically examined with a beam trawl by the s.s. " Goldseeker," as 

 frequently as circumstances allowed, and at dates corresponding as far 

 as possible with those of former examinations, both with the beam- 

 trawl and with the otter-trawl. A report on these investigations and 

 on the statistics is in course of preparation. 



The fish-cultural work at the Hatchery at the Bay of Nigg was con- 

 tinued in the Spring last year throughout the spawning season of the 

 plaice, and is described below. A number of requests for plaice fry 

 were received on behalf of the fishermen at various parts of the coast 

 — Peterhead, Aberdour, Sanclhaven, St. Combs, Cruden, Newburgh — 

 and these were as far as possible complied with, but this could not be 

 done in all cases, owing to the insufficiency of the fry. Along the 

 coast of Aberdeenshire the fishermen have reported a considerable 

 improvement in the plaice fishing, which is also apparent from the 

 statistics of trawlers working in the neighbourhood, which they 

 attribute to the liberation of many millions of fry during the last ten 

 years. In that period close upon 200,000,000 fry of the plaice from 

 the Hatchery have been liberated in the sea off the coast of Aberdeen- 

 shire, about 50,000,000 of which were deposited in the vicinity of 

 Fraserburgh. 



The Hatching Operations. 



In the course of the season of 1911 the estimated number of eggs of 

 the plaice that were dealt with at the Hatchery at the Bay of Nigg 

 was 6,200,000, and the number of fry hatched from them was 

 approximately 5,680,000. As explained in former Reports, the adult 

 plaice of both sexes are retained in a large tidal pond, into the water 

 of which the eggs are shed, and where they are naturally fertilised 

 during the spawning season. The floating eggs are collected at 

 intervals by means of a fine net and transferred to the Dannevig 

 hatching apparatus, hatching taking place in between three or four 

 weeks, as a rule, in the early part of the season, in January and 

 February, and about a week sooner in the latter part of the season, in 

 April and May. The period, however, varies with the temperature. 



