102 



TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



REPORT ON PLAICE MEASUREMENTS, 1920. 

 By W. Birtwistle. 



Although a few samples were examined in the early part 

 of the year, the main investigations did not commence until 

 June, and the bulk of the data was obtained between this month 

 and the end of the year. 



The measurements of length alone were all carried out 

 on board on live fish, either in the sailing cutters or on the 

 fishery steamer " James Fletcher," and the age and weight 

 determinations were made in the Fishery Laboratory of the 

 University of Liverpool from unselected samples of the ordinary 

 catches. The three mam areas sampled were Nelson Buoy, 

 Mersey Estuary and North Wales. 



Nelson Buoy Area is the area enclosed by a line drawn 

 N.E. from Morecambe Bay Lightship to Walney, and a line 

 drawn S.S.E. from Morecambe Bay Lightship until Formby 

 Point is due East. Join these points for the southern limit. 

 It does not include the area enclosed by a line drawn from 

 Roa Island to Sunderland Shoulder. 



Mersey Estuary includes all that area enclosed by a 

 line drawn from Formby Point to Point of Ayr (Wales). 



North Wales includes all that area between Point of 

 Ayr and Point Lynas. It includes Beaumaris Bay to the 

 northern entrance to the Menai Straits. 





Summary of Fish measured at Sea 



■ 



Area. 



Number. 



Period. 







8,046 



5,656 



7,653 



1,249 



414 



1,152 



1,177 



194 



415 



June-December 





North Wales 







Mersey Estuary 



J5 





" 



November-December 



April- August 



Shrimp Trawl. 

 6 inch Trawl. 





January-December 





Cardigan Bay 



April -September 



" 









Morecambe Bay 



August-December 



Stake Nets at 





Flookburgh 



Total 



25,956 







