_ 7 — APPENDIX H: GARSTANG 



the Jutland and Holmen Outer Grounds, the larger fish showing the northward tendencj^ in a 

 pronounced manner (of. experiment Da 4, — 9 on the chart). 



Experiments Da 5 and 2 + 3 (10 and 1 1 on the chart), north and south of the Horn 

 Reef respectively, showed the same general tendency of migrations in a north-westerly direction 

 towards the Horn Reef Outer Grounds, which were reached in some cases during July and by 

 the preponderance of recaptures in August and September. Two non-migrant fish were recovered 

 in Graa Dyb in November, but the few remaining captures during the winter months (December 

 and January) were taken offshore in a more southerly latitude than was shown by the great 

 majority of recaptures during the autumn months. The fish in question were of small size 

 (21 to 23 cm.), and it is possible that they had migrated directly westwards from the point 

 of liberation; but in view of the experiments shown upon the winter chart, it appears more 

 probable that they had first migrated in a north-westerly direction and had then partaken of 

 the general southward tendency during the winter months as shown by the German experiments 

 to be described below. 



The German experiments in the Heligoland Bight showed a northward tendency on the 

 Sylt Grounds in the spring months (experiment 13, — 12 on the chart), but a distinct north- 

 westward tendency during the later summer and autumn months. The fish marked off Heligoland 

 were recovered during May and June in the neighbourhood of the island, but during July to 

 September in two groups, an inshore group in the neighbourhood of the island and an offsliore 

 group extending from Clay Deep to the Southern Mud Bank. It is conceivable that the fish 

 recovered in the offshore area had first migrated northwards in accordance with the tendency 

 shown by experiment D 13 (12 on the chart), and then westwards from the Horn Reef Grounds; 

 but it is more probable that the lack of continuity between the inshore and offshore areas of 

 recapture is due to the small amount of fishing which takes place on the intervening ground, 

 which is unsuitable for commercial trawling (Oyster Ground). As is shown by the results of 

 the international trawling experiments, a distinct lowering of the average size takes place 

 over this area in the autumn months, coupled with a marked increase in the abundance of 

 plaice, which are obviously migrating at this season towards the offshore grounds. In October 

 and November the recaptures from the German experiments were limited to the area south-east 

 of the Dogger Bank. The winter recoveries are limited to three fish recovered during March, 

 1904, two in the neighboui'hood of Norderney, clearly non-migrant fish, and another west of 

 the Dutch coast, off Scheveningen. Whether the latter fish (28 cm.) had migrated westwards 

 along the inshore grounds or had migrated southwards in the winter from the Clay Deep region 

 must remain for the present uncertain. 



The English experiments in the southern part of the Flemish Bight (14 and 15 on the 

 chart) showed an exclusively nortliward tendency, the fish being recovered during the summer 

 months on the Brown Ridges and Leman Shoals. Prom Winterton Shoal (experiment 10 on the 

 chart), the fish were found westwards and northwards within a limited area during the summer 

 months; but one fish (31 cm.) was recaught on the Shoal of the Dogger Bank in the following 

 February. In the Leman Ground experiment (17 on the chart) the fish remained in the same 

 region during the whole of tlie summer, some tending slowly in a northerly direction, others, 

 especially the smaller fish, distributing themselves among the Leman Shoals west of the 

 Swarte Bank. Two outlying fish were reported during June and Jnly from grounds North 



