6 Fishery Board for Scotland. 



cured on the 6th November, 1907, at Station 3 (Lat 59° 10' N. 

 Long. 1° 27' W.), and they seem to suggest that the glass-eels gain 

 access to the North Sea through the passage between Orkney and 

 Shetland. The two specimens captured on 21st November, 1912, 

 at Lat. 58° 30' N. 2° 30' W., right at the Pentland Firth, on the 

 other hand, suggest the view that part of the stock may come 

 through the Pentland Firth into the North Sea. 



The most interesting record is probably one made in December, 

 1902. A specimen was taken by H.M. " Jackal " on the 8th of this 

 month, at Lat. 61°12'N. 10°52'E. Here is an individual which 

 has been carried very far to the north-east, even as early as Decem- 

 ber ; but this record is the more easily explicable when taken in 

 together with the record of the Leptocephalus caught to the north 

 of Shetland in the month of August. There is no doubt that a great 

 part of the supply of eels to the northern shores of Norway is derived 

 from the Atlantic by way of the Faeroe-Shetland Channel, across 

 which the larvae are carried! early by the rapidly-moving Gulf- 

 stream cun-ent. Part of the stock of eels to the west of the Hebrides 

 must be carried towards the North of Scotland, and split fan-like by 

 the intervening Orkney and Shetland Islands before entering the 

 North Sea. 



The other records for December are also interesting, although only 

 single specimens have been found at each observation station. In 

 December, 1908, as early as the 3rd of the month, glass-eels had 

 penetrated into the North Sea as far south as a line east from the 

 Firth of Forth. This is the most southerly limit of our observation 

 stations, so that in reality the stock of glass-eels may have extendted 

 much further south. There is no doubt but that these specimens 

 had come from the north, and it should also be noted that they were 

 captured at localities at some considerable distance fi^om the coast. 

 The probability is that these would have been earned still further 

 south later in the year. The stations which have been examined in 

 January are, unfortunately, very few, but our Februaiy observa- 

 tions are numerous and the records of glass-eels are as frequent as are 

 those of December. This is undoubted proof, therefore, that the 

 glass-eels are fairly general in their distribution over the northern 

 North Sea in the winter months, from December to February, and 

 that they are found even far from the coast. On the other hand, the 

 March observations, which have extended over as wide an area and 

 are more numerous than the February ones, give much fewer records, 

 and the glass-eels captured have been found comparatively near to 

 the coast. Apparently the great annual wave of immigrating glass- 

 eels has pa-ssed over this area between the months of December and 

 February. That this is probably the case is further corroborated by 

 the fact that the glass-eels have completely disappeared from our 

 area in the month of April. Our area of investigation is necessarily 

 limited in extent, and there is no reason for supposing that there are 

 no glass-eels beyond the area investigated. 



The line of stations running east from the Firth of Forth has 

 proved very rich in glass-eels during the first months of the year, 

 numerous records being obtained from the same stations in different 

 years. It is obvious that the glass-eels not only spread over the 

 northern North Sea, but that many are carried coastwise down into 

 the southern portion ; and we are justified in saying that the 



