Ixii 



Thirty-second Annual Report 



Fishery Investigations in the North Sea. 



Since the 1st April 1910, when the international investigations in 

 the North Sea were placed under the direct control of the Board, the 

 fishery investigations of the research steamer, the " Goldseeker," have 

 been under Dr. Fulton's charge, and have been carried out according 

 to a monthly scheme submitted to and approved by the Board. The 

 following is a summary of the work done last year : — 



Trawling Investigations. 



In the course of the year 186 hauls were made with the trawl nets, 

 ^dz., 22 with the ordinary otter- trawl, 118 with the otter- trawl and 

 cod-ends for herring trawling experiments, and 46 with the beam trawl. 

 The herring trawling experiments are referred to below. The hauls, 

 with the beam-trawl were made at the old trawling stations of the 

 " Garland " (the vessel formerly employed in the Board's scientific 

 work), in the Firth of Forth and the Moray Firth. As the investiga- 

 tions of the " Garland " were begun in 1886, and carried on till 1896 in 

 the Firth of Forth and until 1900 in the Moray Firth, comparison of the 

 results as to the relative abundance of the various species of the food- 

 fishes in the two periods will be of value. The trawling with the 

 large otter-trawl was made on various grounds, inshore and offshore. 



In most of the hauls (except with the beam-trawl) a small-meshed 

 net was used outside the cod-end in order to catch the smaller fishes 

 which escaped through its meshes. 



The great majority of the fishes caught were individually measured, 

 the sizes being recorded, while large numbers were opened and the 

 condition of the reproductive organs ascertained and noted. Observa- 

 tions were also made in many cases on the contents of the stomachs, 

 in order to determine the food upon which the fishes subsist. These 

 records are being worked up for publication. 



Migrations and Growth of Fishes. 



The number of food-fishes which were " marked " and liberated in 

 1913 by the " Goldseeker " was 1679, of which 1345 were plaice and 

 254 cod and codling, the remainder comprising six species. The 

 mark consists of a numbered vulcanite disc, attached to the fish by 

 means of a silver wire, or of a vulcanite stud, also numbered, fixed in 

 position by a rubber ring. The main objects of the marking experi- 

 ments are to ascertain (1) the migrations of the fish ; (2) their growth ; 

 (3) the intensity with which fishing operations are carried on. For 

 any of these purposes it is necessary that some time should elapse 

 in order that a sufficient amount of evidence may be accumulated for 

 the formulation of satisfactory conclusions. As mentioned in previous 

 Reports, efforts have been chiefly concentrated on the plaice, which is 

 the most immediately important species in connection with the inter- 

 national fishery investigation, and also, as it happens, the fish which 

 is best adapted for this special method of research, most other species 

 succumbing in large numbers to the treatment to which they are 

 necessarily exposed. Since, however, these marking experiments on 

 the plaice have now been carried on for ten years, and since the Inter- 



