SUMMARY AND GENERAL REPORT. 



The past year has been one of reconstruction. The labor- 

 atory required a complete overhaul involving the building and 

 the equipment. The roof was coated with asphalte, the pipes 

 and electric fittings were repaired and where necessary renewed, 

 and the woodwork and ironwork painted. The apparatus, 

 reagents and nets have been to a large extent replaced. The 

 specimen room has been altered into a chemical laboratory and 

 fitted for the work of the Biochemist. The motor boat, which 

 suffered considerable loss at the hands of depredators in Blyth 

 Harbour, has been reconditioned and her stores renewed, and 

 the opportunit}' was taken to fit her with a " Kitchen " rudder. 



The investigations accomplished during the period and 

 reported upon in the following pages refer in the main to trawling 

 experiments and to a continuation of the researches relating to 

 herring fisheries. 



The trawling experiments which were suspended since 1913 

 were renewed in 1920 with a view to finding out whether the years 

 of the war have produced any change. The results showed 

 that the distribution of the fish, which we had found to be so 

 constant in inshore waters, was maintained, but there were certain 

 peculiarities. Plaice with two winters behind them were abund- 

 ant in the northern part of the Northumberland area, but three- 

 winter plaice and probably also four-winter plaice were just 

 represented. Moreover the two-winter plaice were conspicu- 

 ously below the pre-war size. The conclusion is then that the 

 spawning season of 1917, and probably also that of 1916, was a 

 poor one or that the fry resulting from it were subjected to 

 unfavourable conditions. There was evidence besides that the 

 food inshore was not at all abundant. Whether this be due 

 to a general cause or not, it is evident that the flooding of an 

 area such as the Northumberland inshore waters with oil during 

 the pelagic period of the eggs and fry and food would lead to 

 a great deal of destruction. The effects were seen during the 



