SEA-FISHERIES LABORATORY. 103 



FISH HATCHING AT PIEL. 

 By Andrew Scott, A.L.S. 



The fish hatching operations carried on in 1913 gave 

 results very similar to what we have had in former years. 

 Thanks to the continued kindness of the Fishery Board for 

 Scotland, we are enabled, year after year, to renew our stock 

 of adult plaice from the closed area of Luce Bay. Without 

 such a privilege it is almost certain that a sufficient number 

 of adult plaice would not be obtained in the open area of the 

 Irish Sea in a reasonable time. The results of the plankton 

 investigations conducted in 1913 indicate that there were 

 very few spawning plaice between Lancashire and the Isle of 

 Man. Thirty-nine surface tow-nettings were taken all over 

 the northern area of the Irish Sea between February and the 

 middle of April. Plaice eggs were found in nineteen of the 

 samples, but the total number only amounted to fifty-nine. 

 When it is remembered that a single spawning female plaice 

 may produce 200,000 eggs in the course of a couple of weeks, 

 one naturally expects that the eggs will be fairly numerous if 

 adults are plentiful. It also follows, if adults are scarce, that 

 there will be few eggs floating near the surface. There can be 

 no doubt that closed areas with an environment favourable 

 to the life of the adult fish, and where commercial trawling 

 is prohibited, must be of an immense value to the adjacent 

 fishing grounds. The flounders were caught in the vicinity of 

 Piel by the police cutter belonging to the northern division. 

 A number of flounders were also collected by the steamer when 

 trawling on the off-shore fishing grounds for material for use 

 in the classes. 



The adult plaice and flounders, kept in the tanks all 

 winter, matured much earlier than in previous years. They 

 commenced to spawn on February 25th, and two days later 



