REPORT OF THE COUNCIL. 493 



hour with the trawl (1) in May and (2) in September at various 

 distances along a line between Texel and the Leman Banks, has shown 

 that the mass of eacli age group is situated further from the Dutch coast 

 in the latter than in the former month. These observations distinctly 

 indicate an ofi-shore movement of shoals of successive ages in the 

 course of the summer, as has been shown by the results of marking 

 experiments. These results thus confirm conclusions arrived at by 

 Garstang (Internat. Investigations, Mar. Biol. Assoc. Eeport I, p. 93) 

 from a study of the trawling investigations carried out by the 

 s.s. Huxley concerning the source of the plaice found on the Leman 

 Banks and Ground, and those of liedeke (Proces Verbaux, III, Ap. H) 

 concerning the distribution of plaice off the Dutch coast. 



Trawling Investigations. — The particulars of the trawling stations 

 of the s.s. Huxley in 1904-5, illustrated by charts of the trawling 

 courses, have been published, together with detailed measurements of 

 the plaice caught in these years, and summaries, in 10 cm. groups, of 

 these and other species of fish taken in each haul. 



An examination of the catch per hour of plaice and dabs taken at 

 the fixed trawling stations during 1908 with the otter and beam 

 trawls, both partially covered by small-meshed net and uncovered, has 

 been made, with a view to gaining information as to the constancy of 

 action of each description of gear, and of the relative powers of 

 capture of the otter and beam trawls. Catches from comparable hauls 

 made in earlier years have also been examined, and the catches from 

 day and night hauls made under similar conditions compared. 



From this examination it appears that the day and night catches of 

 plaice made by the s.s. Haxlcy in the North Sea as far north as the 

 Dogger Bank do not differ appreciably. The comparative catching 

 powers of the otter and beam trawls agreed closely with those arrived 

 at by Garstang (Eeport on the Trawling Investigations, 1902-3, 

 Internat. Investigations, Mar. Biol. Assoc. Eeport I, 1902-3, p. 74) for 

 the action of these nets in the same region on a similar bottom. 



Experiments with Small -meshed Nets Covering the Commercial 

 Tkawls. — The measurements of fish taken in trawls covered in whole 

 or in part by small-meshed net have been tabulated. Eliminating 

 twenty experiments in which the net was torn, a total of over 

 112,700 fish, taken in 118 hauls, have been treated. 



In all these experiments the cod-end was covered, sometimes alone, 

 sometimes with part of the batings, with all the batings, with the 

 batings and square, or with all the trawl except the belly. The 



