COUNCIL — JULY 1905 — APPEND. E 86 
The results, so far as the plaice — the principal species of the region — is 
concerned, are summarized in Table III. As the duration of the hauls on the 
different kinds of grounds was not always the same, the method adopted to obtain 
comparability has been, to take the maximum number of hours fishing on any 
ground as the standard and to multiply the duration of the fishing on the other 
grounds, and consequently the numbers of fish, by the factor necessary to bring 
each to the same standard. 
The table shows, that whilst the great majority of the plaice (87°/o) was 
laken on sandy or muddy ground, yet a considerable percentage (13°/o) was caught 
on gravel, gravel and stones, and stones i.e. on rough ground. 
The size of the plaice taken varied between 22 and 47 cm. (81/2—19 inches). 
The importance of these results will be understood when the North Sea is 
taken into consideration. As shown in Appendix K of the General Report, a con- 
siderable portion of the North Sea is rough ground and not suited to trawling. 
Further, gill-nets are not used in the open North Sea and lines catch but an insig- 
nificant proportion of the plaice landed annually. Consequently, the plaice which 
live on rough ground in the North Sea are practically immune from capture. If 
therefore 13°) of the adult plaice living in the North Sea are from year to year 
safe from capture, it may be concluded from this and from the quantities of plaice 
captured each year (see Appendix K of the General Report or the Statistical 
Tables on the plaice given in this Report), that there never will be a lack of 
spawning place in the North Sea sufficient in number to populate the inshore 
areas with their young. Consequently, any practical solution of the problems of 
overfishing, so far as they regard the plaice, need not take the adult plaice nor 
the very young plaice into consideration. 
These conclusions, however, depend as shown on the simple experiments 
which have been made in the Kattegat by Sweden. It is obviously in the highest 
degree desirable, that similar experiments should be made on the more exposed 
rough grounds of the North Sea. 
The principal results of the Belgian experiments are summarized 
in Tables IV and V. The net employed was a small sized beamtrawl of 8—10 
metres beam, and the meshes of the cod-end were 2—2:5 cm. measured along one 
side of the mesh. The cod-end including pockets was completely covered by 
shrimp-netting above and below, so that all fish of any size at all which escaped 
through the meshes of the ordinary cod-end were caught by the shrimp-netting 
