134 American Fisheries Society. 



that specimens of a non-indigenous species are seen a year or even 

 two years after introduction does not prove that the species is es- 

 tablished; for, while the individuals may exist for the periods of 

 their life-times, the life cycle must be complete before the species 

 can be considered established. That is, if the original introduction 

 was made with yearlings, yearling fishes must be produced in the 

 waters from their offspring before it is definitely shown that the 

 species can exist therein. Misinterpretation of conditions such as 

 this, based upon inadequate observation and experience — plus the 

 difficulty of obtaining fish, particularly the warm water varieties 

 for lakes and ponds, tends to concentrate the owner's attention to 

 securing of fish alone. Haphazard plantings then prevail, and 

 though natural results nearly always come about slowly, no defi- 

 nitely progressive policy is adhered to ; and even though a wise 

 plan may have been originally chosen, relapses occur which are 

 fatal to success. Much money, effort and time are lost by mis- 

 guided attempts to improve the situation, and after a number of 

 years the fish life is probably less plentiful and the entire aquatic 

 environment more unbalanced than before anything was at- 

 tempted. 



It has long been an axiom of mine that whatever condition 

 exists tends to become intensified, and that in time cause becomes 

 effect and effect cause. In other words, cause and effect become 

 more and more inseparable ; and the condition continues to develop 

 at constantly accelerating speed unless it is met by other forces. 

 Fortunately it would appear that the very nature of things has de- 

 creed that most situations have their compensation and a balance 

 is established before serious collapse occurs due to overweight in 

 any particular direction. The question now is — with a thorough 

 understanding of the effect civilization is working upon our native 

 fishes — can we apply the conpensating force? 



It is my firm belief that the solution must be sought by study 

 tending to extend our fish culture to include adjustment of aquatic 

 environments. The advance which modern hatchery practices gain 

 for the young fish must not end when they are planted. The years 

 of experience behind the months of effort with the particular fish 

 used in any given problem must not be vitiated by lack of under- 

 standing of the basic laws which control those fish after their libera* 

 tion in open waters. Mere stocking is too frequently dealing with 

 effects. Adjustment deals with causes. From now on we must 



