298 FOUNDERS OP OCEANOGRAPHY 



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 shellfish, 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 fisherman 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 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 recognize them when caught 

 as adults ; nor is it practicable to devise the control experi- 

 ment of both adding to and not adding to the same fishery, 

 or two exactly similar fisheries, simultaneously, so as to 

 secure comparable results. But it may be pointed out that 



