46 Ti^'ciify-siAilt A initial Meeting 



annually, \vc may take from it a certain product. If we attempt 

 to take more the field Ijecomes exhausted and refuses to yield. 

 We cannot increase the yield by doul)ling' the number of seeds 

 planted; we cannot increase it l)y adding to the annual supply 

 of fertilizer. Our Great Lakes are limited in ])recisely this way. 

 l^'ertilizers they get from the tri])uldry streams and from the 

 erosion of their shores. The\ are cajjable of yielding a certain 

 annual return in fishes. What that return should be we do not 

 know. We cannot add to the supply of fertilizing material, as 

 we might in small ponds. It is useless to ])lant more fish than can 

 live. Enough should be planted, and until the fisheries are re- 

 stored and the catching of immature fish stopped, it is not likely 

 that planting can be overdone. lUit with it all let us remember 

 the limited productive capacity of these lakes and let us learn 

 from this that the only thorough going remedy is to restrict the 

 fishing within that capacity. This seems to me to be the most 

 important lesson to be drawn from recent studies in fresh water 

 biology. 



DISCUSSION. 



Mr. Clark: Mr. President: In reference to this paper of 

 Professor Reighard's, I was unfortunately called out, so that I 

 only heard the first part of his paper. l)ut a thought occurred to 

 me in connection with what I did hear and I think I had better 

 mention it. It was in regard to the different States commencing 

 these scientific observations of the fresh water lakes. ( )f course, 

 the members and others know what the United States Commis- 

 si(Mi has done in a scientific way. for salt water, and this thought 

 occurred to me, it was to l)e regrettetl that something has not been 

 done in this direction on the great lakes by the United States 

 Fish Conunissiou. I am glad the United States iMsh Connnis- 

 sionrr ex]);.'cts to take up that work, and intends ^o establish 

 scientific stations on the great lakes. In a cc^iference I had with 

 Dr. Smitli and others of the In.sh Conunissiou in Washington 

 reccntiv, I was told it was expected to take it up this season. 

 Thev realize its im])ortance and that it should be done, but I very 

 much doubt their taking hold of it this session, as the money, 

 within the last few weeks, as tlie su])erintendents here know, is 

 short. Put it is the full intention of the United States Fish Com- 

 mission to take h.old of that work. 



Mr. Stranahan: I would like to ask the professor what 

 the amount of plankton in Lake Erie was. as compared with the 

 other lakes, just in an off-hand way? 



