EEPORT OF THE COUNCIL. 63 



the Bishop and in the Bristol Channel. The Plankton on the western 

 stations was unusually rich in oceanic species, a fact which leads to 

 the conclusion that this southerly current is accompanied by and 

 probably due to a simultaneous movement of water from the Bay 

 of Biscay in a northerly direction. 



By November 1906 the surface salinity of the English Channel had 

 risen generally, the 3 5 '4 isohaline in the western area roughly coincid- 

 ing with the August isohaline of 35 "o, while to the east of the Isle of 

 Wight-Cherbourg line the area which during the August cruise had a 

 salinity of 35"0 to 35"1 was filled with water of from 35'1 to 35*2. The 

 southerly flow of low salinity water from the Irish Channel to the 

 west of the Scilly Islands was even more sharply defined on its eastern 

 edge than in August. It extended at least as far south as Parson's Bank, 

 where the surface salinity was 35"33 compared with 35-37 in August. 

 The western edge lies outside the area of the quarterly cruises, and the 

 only observations available are from liners which only cross its northern 

 extremity. Its approximate dimensions on the surface south of the 

 latitude of Land's End may be put at 100 miles in a north and south 

 direction, and 25 to 30 miles across. It reached the bottom at all 

 stations except 4 and 5, wdiere its thickness was about 30 metres, the 

 water below that depth being of higher salinity. In view of the steep 

 salinity gradient to which this current frequently gives rise on the sur- 

 face, and its possible importance to the Plankton investigations, it would 

 be advisable to devote a special cruise of three or four days to its 

 examination, particularly on its western edge. 



The samples from the February cruise have been analysed, but the 

 results have not yet been plotted. The most striking point is the 

 continued fall of the salinity on Station 4 (Parson's Bank), accompanied 

 by a rise at Station 5. The water was of the same composition at all 

 depths. 



Two stations were worked south-west of the Start at the end of 

 March, when mackerel were being caught by trawlers on the bottom. 

 The results were much the same as in February, and present no point 

 of interest. 



In May five new stations in the Bristol Channel were added to the 

 programme. It had originally been intended to work this area on the 

 same day on which the steamers of the Irish Fishery Department and 

 the Lancashire Sea Fisheries Committee were to carry out similar 

 investigations in the adjacent waters, but this was unfortunately pre- 

 vented by a gale which interrupted operations for some days. 



During the year samples of Plankton were taken as usual on the 

 four quarterly cruises, and also at frequent regular intervals at 

 Plymouth, and at several light-vessels off the English and Irish coasts. 



