284 TBANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



been caught in the neighbourhood of the station, and 

 other three (not included in the tables) from Morecambe 

 Bay. 



Intensity of fishing. 



It is customary, in investigations of this kind, to use 

 the results for making deductions as to the intensity of 

 fishing in the areas dealt with. If, say, 100 plaice arc 

 liberated and spread themselves over a comparatively wide 

 area, and if within a certain period, say one year, 50 of 

 these are recaptured, it may be argued that of all the 

 plaice present on the same area 50 per cent, have been 

 captured during the same year. Information to form such 

 estimates of the intensity of fishing on the East side of 

 the Irish Sea is afforded by the summary table. In the 

 case of nine experiments the data are complete — a 

 complete year having elapsed between the time when the 

 fish were liberated and the time when the summary was 

 drawn up. The last column gives the percentages 

 recaptured, and the figures may mean that in the course 

 of one year 6 per cent, of the plaice in Luce Bay and 

 the adjacent waters were captured, 12 per cent, of those 

 on the fishing grounds round the Isle of Man, and so on. 

 Now we may leave the Luce Bay experiments out of 

 consideration, and those made on Stations III. and I\ . 

 may also be ignored, since these two experiments were 

 vitiated by the faulty nature of the labels employed. On 

 the other hand, Experiments V., VI. and VII. may be 

 considered together, since most of the fish liberated on the 

 stations so numbered have apparently spread themselves 

 over much the same area — the Irish Sea North of Holy- 

 head, South of St. Bees Head, and East of the Isle of 

 Mini. Within this area about SO plaice out of ISO have 

 been recovered- -a percentage of about 45. That is to say, 



