American Fisheries Society 97 



elsewhere, should be preserved or replaced, for here the 

 conditions are reversed. The soil for the most part 

 being poor, the actual food value of these streams is 

 much greater than the potential food value of the lands 

 through which they flow. 



The fisheries of the great rivers and lakes and seas and 

 oceans present a far different, and in some respects a more 

 difficult, set of problems than the mines and forests. One 

 reason is that, unlike mines that cannot be restored at all, 

 and forests that may be replaced only at long intervals, 

 most species of fish become adults at three or four years 

 of age and are then capable of reproducing themselves or 

 of being reproduced annually. The main reason, however, 

 is that the vast expanses which are their home, nearly three- 

 fourths of the earth's surface, are for the most part in a 

 state of nature. This means that they are in a condition of 

 savagery, subject to no law save that of the survival of the 

 fittest, but it does not mean that we are powerless to amend 

 that cruel law, that we may not in some degree bring order 

 out of chaos, and thus add enormously to the food pos- 

 sibilities of the state and national and international water 

 domains of the earth. Indeed, more than one amendment 

 to this law has already been passed. Perhaps the most im- 

 portant of these modifications is protected or controlled 

 propagation, which multiplies natural hatching percentages 

 a hundred, or, in some cases, a thousand fold. This 

 wonderful increase in the creation of infant fish is ac- 

 complished by the simple expedient of insuring fertilization 

 of all of the ova and then protecting those ova from most, 

 if not all, of their natural enemies. 



But fish culture in its broadest sense means far more than 

 mere fish hatching, however great importance we may attach 

 to this particular feature of production. Fish hatching 

 solves only one of the many important problems involved in 

 fishery conservation. If we are to utilize the waters to their 

 fullest practicable limit, we must know far more than we do 

 concerning the food, the breeding habits, the range, the 



