330 REPORT OF THE COUNCIL. 



Dredging Investigations. — Extensive series of hauls with Dredge, 

 Conical Dredge and Agassiz trawl were made in the months of June, 

 July and August in the deep water west of the Dogger and on the 

 rough ground between Flamborough Head and Lowestoft and west of 

 3° E. long. In April similar work was carried out on different grounds 

 between 52° and 53° N. lat. 



In voyages 98 and 99 a small trawl with very coarse canvas netting, 

 specially designed for the capture of small fish and Crustacea, has been 

 used with success. 



Fish Measured, — Over 75,000 fish were measured during the year. 

 As in past years, the entire catch was measured on nearly all occasions. 

 The details as to the number of plaice, haddock and other species are 



as follows : — 



Plaice. Haddock. Others. Totals. 



1902-7 Voyages 1-90 107,614 47,240 253,293 ... 408,147 



1907-8 Voyages 91-98 32,350 1,273 41,954 ... 75,577 



Totals 139,964 48,513 295,247 ... 483,724 



Measurements of plaice accompanied by observations on maturity 

 were also carried out, both at sea on a Lowestoft fishing-smack and at 

 the Lowestoft market. In this way 1810 plaice were dealt with at sea 

 in January, while in the observations on the market, which were made 

 almost daily in November and December and at intervals throughout 

 the first quarter of 1908, 10,786 plaice were examined. 



Marking Experiments. — During the past year 2159 plaice and 15 

 other fish have been marked and set free. Of the marked plaice, 1430 

 were transplanted from the Dutch and Danish coastal grounds to the 

 southern shoals of the Dogger Bank in May, 1908, with a view of 

 obtaining information as to their rate of growth in 1908-9. 



The more noteworthy of the remaining experiments were directed 

 towards ascertaining the movements of plaice in autumn in the deeper 

 water bordering the Dogger Bank, and of the spent plaice which were 

 leaving tho spawning grounds in the southernmost portions of the 

 North Sea in spring. With these objects 278 plaice were marked at 

 various positions round the Dogger Bank in August, 1907, and 190 

 plaice, including spent females of 35-40 cm. in length, were marked 

 near Smith's Knoll Light Vessel in March, 1908. 



Of the plaice marked from June 1st, 1906, to May 31st, 1907, 387 or 

 187 % were returned before June 1st, 1908. Of the fish marked in 

 the year 1905-G, 25-6 % were returned before June 1st, 1907. These 

 percentages are only comparable in a rough sense, since the times 

 elapsing between the various experiments and the 31st of May following 

 do not necessarily correspond in ihe two years. The difference is, how- 



