13-4 NORTH SEA INVESTIGATIONS. 



The character of the plaice in the intermediate region from the Texel 

 to Nordeney has not been examined, and the limit of the smaller race 

 cannot be exactly stated. It is more probable that there is a transition 

 from one race to the other than a definite boundary between the two. 



It is important, as well as interesting, to notice that other biological 

 features of the English Channel, as well as the small size of its plaice, 

 are found to extend into the North Sea along the Dutch coast, and 

 some of these extend as far as the German Bight, although the plaice 

 there are not similar to those of the Channel. I am referring here to 

 the fact that certain southern fishes which are found in the Channel, are 

 also found along the Continental coast as far as the neighbourhood of 

 Heligoland. The first of these to be mentioned is the anchovy. The 

 history and migration of this fish has been repeatedly discussed in 

 previous numbers of the Journal, and it has been often mentioned that 

 there is a regular fishery for anchovies in summer in the great Dutch 

 estuaries, namely, the Schelde and the Zuyder Zee. Dr. Ehrenbaum 

 on one occasion found the eggs of the anchovy in abundance in the 

 open sea farther east, near the Island of Nordeney. On the East Coast 

 of England the anchovy occurs but rarely, and in very small numbers, 

 except in the Straits of Dover. The second case is that of Trigla 

 Mrundo, called by the east coast fishermen the latchet, by Plymouth 

 men the tub. My records show how constantly this fish is taken in the 

 trawl, both on the Brown Eidges and in the German Bight, as far north 

 as the Horn Reef, while on the English side it is seldom taken. The 

 third case is that of the mackerel. Mackerel fishing takes place off 

 Lowestoft in May and June, and again in September and October. 

 South of the Horn Eeef, in May, we took several large mackerel in the 

 trawl, but I believe there is no regular fishery for mackerel in that 

 neighbourhood. Mackerel are usually found in summer in the Moray 

 Firth, but there is no fishery for them between that region and the 

 Wash. 



It would be interesting to discuss fully the relation between the 

 biological facts here described, and the physical conditions in different 

 parts of the North Sea. A series of careful physical observations has 

 been carried out recently, according to an international scheme, in 

 which Britain and Denmark, Germany, Sweden, and Norway have 

 co-operated, the initiative in Britain having been due to the Scottish 

 Fishery Board. The investigation of the channels connecting the 

 North Sea with the Norwegian Ocean and Atlantic have been described 

 by Mr. H. N. Dickson, and a paper on the observations in the more 

 southern parts was read before the British Association last year. But 

 these latter observations have not yet been published in full, and 

 therefore their consideration in relation to the present subject must 



