OUR FOOD FROM THE SEA 195 



Halibut, a northern fish of large size. 



Sole, commoner in the south down to Morocco ; a shallow-water 



fish common in the Irish Sea. 



Turbot, in deeper water ; a North Sea fish, but not very abundant. 

 Brill, more abundant than the Turbot, especially in the south. 

 Plaice, a northern form, very abundant on the coasts of Iceland 



and farther north, distributed all around our coast and 



important as a food of the people. 

 Flounder, of less importance ; especially abundant in estuaries. 



It is in connection with some of these more sedentary flat 

 fish that depletion of certain fisheries has been most clearly 

 established, or, to put it more cautiously, that it is felt that 

 there may be risk of the fishery being depleted on certain 

 grounds. The more widely roaming herring, mackerel, cod and 

 haddock are probably safe from man's ravages ; but the more 

 local, bottom-haunting sole and plaice are less independent 

 and more at the mercy of their immediate environment, 

 including the fishing fleet. It is therefore in connection 

 mainly with such fish that attempts have been made in the 

 United States and several European countries to compensate 

 for the ravages of the fisherman by artificially hatching and 

 rearing young flat fish to add to the stock in the sea. 



One of the most important and practical questions in the 

 whole range of marine zoological investigation is : Can we 

 increase the yield of our fisheries by cultivation ? We can 

 cultivate shell-fish, such as oysters, mussels and cockles, on 

 the seashore with much profit. Can we do anything towards 

 farming our inshore or offshore fishing-grounds ? The fisher- 

 man at present is a hunter of the fish, can we reasonably hope 

 to make him in time a farmer, reaping a harvest that in part 

 at least he has sown ? These are the ideas that have led to 

 the hatching, rearing and transplanting operations which are 

 carried on with more or less energy and success in various 

 parts of the world. 



It is by no means easy to determine whether the artificial 

 hatching of sea-fish has as yet had any effect upon any local 

 fishery. It is not possible to mark or brand your larval fish 

 from the hatchery so as to recognise them when caught as 



