SEA- FISHERIES LABORATORY. 189 



SEA FISH HATCHING AT PIEL. 

 By A. Scott. 



For some years now our hatching operations have 

 been limited to the incubation of the eggs of plaice and 

 flounders. This is chiefly due to the comparative ease 

 with which the adults can be kept in captivity for 

 lengthened periods. The limited tank accommodation 

 at Piel prevents the keeping of the adults through the 

 summer months. At other hatcheries, provided with 

 large ponds, as at Port Erin, confinement of the spawners 

 from one year to another presents very few difficulties. 

 The method found most practicable at Piel is to collect 

 the adults in the autumn and set them free after the 

 spawning is over. They are thus retained for about 

 eight or nine months. In the winter months there is 

 scarcely any mortality ; any deaths that do occur are due 

 to injuries received when the fish are captured. , AY hen 

 the spawning season is over and the summer approaches, 

 a high death rate sets in. To prevent this absolute loss 

 to the fisheries, the spent fish are returned alive to the 

 sea, when we are satisfied that no mure eggs can be 

 secured from them. 



Through the kindness of the Fishery Board for 

 Scotland the Lancashire Fisheries steamer has been 

 allowed to trawl in the closed waters of Luce Bay for 

 adult plaice during the autumn of the past few years. 

 The adult flounders were formerly caught in the Barrow 

 Channel, but since the removal of the Fishery Officers to 

 Knott End, our supply now conies from the Lune and Wyre. 

 The comparatively long distance that the fish have to be 

 brought, especially in a half-decked fishing boat, such as 



