180 



General Remarks on the Migration Experiments. 



The spawning grounds of the plaice are in the water of 

 15 to 20 fathoms in depth, off St. Bees' Head, in Cumberland, 

 and somewhere in St. George's Channel. The eggs produced 

 in the northern spawning ground drift mostly into the Solway 

 Firth and into the Bays on the S. Coast of Scotland to replenish 

 the iiurseries there. The eggs produced in St. George's Channel 

 drift to the N.E., round Holyhead, and are reared on the 

 nurseries just oft" the Cheshire and Lancashire coasts. The 

 drift of the eggs and larvae is a passive one, due to winds and 

 resultant tidal currents. 



The baby plaice live on the nursery grounds until they are 

 about 20 cms. in length and about three years old. Then they 

 begin to migrate. 



They move out to deeper water oft the coast during the 

 summer months. The more vigorous ones continue to migrate 

 to the grounds off the N.E. Coast of Isle of Man, or to the 

 North Welsh grounds. Most of the others return back again 

 to the nurseries during the months September to December. 

 Next year these latter plaice migrate offshore again and 

 probably succeed in moving away altogether from the nurseries. 



The grounds oft" Ramsey Bay (Shoals, etc.) and those 

 between the N. Coast of Anglesey and Carnarvon are in the 

 nature of " relays " in the plaice migrations. The fish remain 

 there for some time and then reassume their migrations. By 

 the end of January all the plaice have usually left the Red 

 Wharf -Beaumaris Bay region, and they can be traced down 

 into Carnarvon and Cardigan Bays. Later on they go offshore 

 somewhere in order to spawn. During January and February 

 the plaice tend to leave the Shoals region and they probably 

 migrate over to the Cumberland and Lancashire coasts. 

 The larger ones from the Shoals area, and possibly mature 

 fish from the Solway Firth and the South Coast of Scotland, 



