Iviii 



Twenty -ninth Annual Report 



PART III. 



SCIENTIFIC INVESTIGATIONS. 



During the year 1910 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, Sandhaven, 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 especially the fishermen report a considerable 

 improvement in the plaice fishing, which they attribute to the libera- 

 tion of many millions of fry during the last nine years. In that period 

 very nearly 193,000,000 of the fry of the plaice from the Hatchery 

 have been liberated in the sea off the Aberdeenshire coast, about 

 45,000,000 of which were deposited in the neighbourhood of Fraser- 

 burgh. 



The Hatching Operations. 



In former reports the various processes involved in the hatching 

 work at the Bay of Nigg have been described, and an account given 

 of the Hatchery itself. It is sufficient to say here that the adult 

 plaice, which are obtained by the s.s. " Goldseeker," usually in the 

 Moray Firth, are retained in a large sunk tank or tidal pond, into 

 which the sea water flows at high tides, where they are fed and cared 

 for until the spawning season. They then begin to shed their eggs 

 naturally, as they would have done if they had been left in the sea, 

 the eggs being fertilised by the males as they are emitted, after which 

 they float in the water. They are removed by means of a large gauze 

 net, and are then transferred to the hatching apparatus, where they 

 are subjected to a constant current of filtered sea water until they 



