200 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



(e) The Luce Bay Fishery. 



Luce Bay is, of course, within the area of jurisdiction 

 of the Fishery Beard for Scotland, and we have only 

 investigated it to the extent that observations have been 

 made while we were trawling there* for spawning plaice 

 for the Piel Hatchery. All the plaice caught, 7,748 in 

 all, during the years 1908, 1909, 1910, 1911, and 1912, 

 were measured, and Table XVI gives these frequencies. 

 These records are probably of considerable value since they 

 show the distribution of lengths on a natural plaice ground 

 which is closed against trawling by any kind of vessel, 

 and which is, therefore, exploited by fishermen only 

 to a relatively restricted extent. All the hauls, which 

 were made during the months of September and December, 

 are grouped together. It will be seen that the distribu- 

 tion is remarkably asymmetrical : had small-meshed nets 

 been also employed, it would have been still more 

 asymmetrical. The total range is from 10'5 to 63 cms.; 

 the mean is at 26'8 cms., and about 28 % of all the fish 

 are less than 21*3 cms. (8^ in.), about 24 % being over 

 34*2 cms. (13J in.); 50% lie within the limits 213 and 

 34"2 cms. The dispersion is, therefore, very much 

 greater than that of any other plaice length-distribution 

 studied by us. 



The Luce Bay area would well repay investigation on 

 a far more extensive scale than we have yet been able to 

 undertake. It is probable that it is an area which is, 

 to a limited extent, populated by plaice actually reared 

 there, that is, it contains " nursery grounds." Marking 

 experiments have been carried out in Luce Bay, though 

 on a rather inadequate scale, some 300 plaice in all having 

 been dealt with. The recaptures have been few (about 

 45 in all), but so far as they go the results are consistent 

 * With the permission of the Scottish Fishery Board. 



