SEA-FISHERIES LABORATORY. 179 



nearly constant, dropping again in 1898. The maximum 

 catch of dabs was made in 1894 ; from 1894 to 1897 the 

 catches of dabs steadily declined, recovering again in 

 1898. The maximum catch of whiting was made in 1895, 

 and the catches then decreased till 1897, when they again 

 began to increase. It is singular that the maximum 

 catches of these three fishes, plaice, dabs, and whiting, 

 are observed in three consecutive years. 



The catches of soles, on the contrary, show a nearly 

 regular increase during those seven } 7 ears. The minimum 

 catch was made in 1894, the maximum in 1898. The 

 decrease from 1898 to 1899 is very slight. We have 

 evidence that a similar, though greater, increase in soles 

 has taken place on the Blackpool closed ground. 



No deduction as to the effect of fishing on the distribu- 

 tion of these fishes during the period considered can, of 

 course, be made. The period is too short and the varia- 

 tions observed are too great. There can be little doubt 

 but that the fluctuations are due in the main to the 

 operation of natural causes. 



We must insist on the inadequacy of these statistics to 

 a thorough understanding of the causes influencing the 

 distribution, on different areas and at different times, of 

 the fish population of the Mersey shrimping grounds. 

 So far as they go they are valuable, and they do give some 

 information regarding the seasonal variation and the 

 relation to each other of the various forms considered. 

 But they suggest many more problems than they aid us 

 in answering. The increase in the catches of soles on the 

 Blackpool and Mersey grounds is an instance. This 

 happening on two grounds, one preserved against, the 

 other open to, shrimp trawling, is remarkable. A satis- 

 factory answer might have been given by a much more 

 complete series of observations than we possess, which 



