SEA-FISHERIES LABORATORY. 87 



captured 68 score pounds, or over half a ton, on September 

 28th. Another with nineteen nets captured over 200 score 

 pounds, or nearly two tons, of plaice on September 29th. 

 The plaice were so abundant at this particular period that 

 large catches were taken even during the day tides, when 

 low water was in the late afternoon between 5 and 7 p.m. 

 The fishery diminished very much in value after the middle 

 of October owing to the continuance of strong winds which 

 drove the fish further up the bay. A succession of southerly 

 and westerly gales in November set up heavy seas which 

 broke down the stakes and in many cases completely wrecked 

 the nets. The quantity of plaice captured in the stake-nets 

 at Roosebeck in the last four months of 1916 amounted to 

 nearly 3,000 cwts. 



Samples of the plaice were secured at frequent intervals 

 so that they could be measured, weighed and examined for 

 the age and sex conditions. The size ranged from 18 cm. 

 to 48 cm. The majority of the plaice were between 23 cm. 

 and 27 cm. Quite a number of the larger sizes of over 30 cm. 

 were mature fish which would certainly have reproduced in 

 the spring of 1917. The largest one examined measured 48 cm., 

 nearly 19 inches in leng*th. It weighed 1,407 grammes = 3 lbs. 

 1-6 oz., and was a female with the ovaries well developed. 

 The age as indicated by the otoliths was n -f- 5 (six years). 

 The stomach and intestines of every plaice examined were 

 filled with broken mussel shells, showing that the fish were 

 feeding exclusively on the young mussels which were then 

 covering the beds near where they were captured. Previous 

 to this invasion of plaice, the beds were stocked with mussels 

 between 10 mm. and 20 mm. long. Very few mussels were left 

 when the fishery ended. 



In pre-war days the Roosebeck fishermen usually received 

 2s. 6d. per score pounds for their plaice. When the price 

 happened to reach 3s. Od. per score pounds the fishermen 



