10H 



TRANSACTIONS LTVKHl'OOL BIOLOGICAL SOCIETY. 



I. Discussion of the Statistics. 



We have taken advantage, however, of the ten years 

 series of observations to split up the whole period into two 

 quinquennia] parts, and to compare the average catches 

 of immature fishes and shrimps during the hist period 

 (1893-7), with those of the second (1898-1902). It is 

 hoped that by this treatment of the figures, irregularities 

 due to conditions referred to Later, are smoothed out, and 

 that the data really represent the average condition of the 

 grounds during the two five-yearly periods. The greater 

 number of hauls have generally been made during the 

 three months July, August and September, and as it is 

 during those months that fish are most numerous on the 

 grounds, they are the most convenient periods of the veins 

 to compare. But to confirm the results, the -1th quarters 

 of the years, October-December, in the case of tin' 

 Blackpool grounds, and the 2nd quarters, April-June, are 

 also compared. 



Blackpool Closed Grounds. 

 Average catches of immature fishes and shrimps made 

 with a shrimp trawl during the 3rd and 4th quarters of 

 the two quinquennial periods, 1893-7 and 1898-1902. 





No. of 

 Hauls. 



Soles. 



Plaice. 



Dabs. 

 L932 



Whiting. 

 259 



Shrimps 

 (Quarts). 



3rd qr. I 

 1893-7 i 



7 



26 



1268 



2-5 



3rd qr. ) 

 1898-1902 J 



-■ 

 8 



415 



231 



1316 



296 



4 



4th qr. ) 

 1893-7 )" 



1 

 12 126 i 1017 



5840 



245 



5 



4th qr. ) 

 1898-1902 J 



3 



136 727 



1049 



125 



4 



