THE IMPOVERISHMENT OF THE SKA. 25 



If these figures be compared with those advanced by Mr. Knott for 

 the years 1860 to 1864, the fall in the annual catches becomes still more 

 striking, whether prime fish alone or the total catch be considered. 

 The return provided by Mr. Alward for 1867 forms a connecting link 

 between the two series, and shows that there is no ground for dis- 

 crediting the results of a comparison between them. 



The explanation, however, of the very extraordinary catches of prime 

 fish by the trawlers from 1860 to 1867 requires consideration, since it 

 is not so obvious as that of the abundance of plaice. It is known that 

 an extension of the trawling grounds on the Dogger Bank took place 

 in 1860 and 1861, according to Mr. Alward's chart* of the fishing 

 grounds ; and also that the new grounds, when first exploited, were 

 found to be very rich, especially in plaice and haddock (Sea Fisheries 

 Commission, 1865, §§ 4,777-81, 6,908-10, 7,562, 7,672-8, 11,117-24). 



The abundance of the two latter species appears to have been main- 

 tained down to the year 1876, since the offal catches of Mr. Knott's 

 trawlers may safely be taken to have consisted principally of these 

 fishes, and the corresponding items in Mr. Alward's returns did not fall 

 below the same high average until the year 1877. This is a long period 

 (seventeen years), and although there is a gap of seven years — from 

 1868 to 1874 — in the returns, the evidence undoubtedly points to the 

 conclusion that the large catches of plaice and haddock were not excep- 

 tional phenomena limited to one or two isolated years, but were indica- 

 tive of the general abundance of these fish on relatively virgin grounds. 



Nevertheless it is far from improbable that the abundance of fish 

 fluctuated at that, as in more recent times, under the influence of 

 climatic causes ; and there is some evidence that the difference between 

 the minimum and maximum catches within the period 1860-7, 

 should be in part attributed to causes of this nature. The evidence 

 tendered to the Sea Fishery Commissioners in 1863 by Grimsby, 

 Yarmouth, and other fishermen tends to show that a general im- 

 provement of the fisheries took place in that year, which was not 

 altogether to be accounted for by the exploitation of new grounds. 

 Thus a Grimsby line fisherman stated in November, 1863, that the 

 catches of liners had considerably increased that season, which was 

 the best in his long experience (§§ 15,942-3); and similar statements 

 were also made concerning soles and turbot (§§ 7,555-8, 16,085). 

 Accordingly the increased catches of Grimsby trawlers in 1863 and 

 1864, both of prime and offal fish, should probably be treated as 

 exceptional features due to the occurrence about this time of excep- 

 tionally favourable physical conditions, just as there is good reason 



* Deposited with the Fishmongers' Company ; printed in Captain Dannevig's recent 

 pamphlet, Fiskcri og Videnskab, Arendal, 1899. 



