16 Conservation Department 



Plankton Studies. — All fish in their young stages require a 

 plankton diet. Some species, like the alewife or cisco, are 

 "plankton sifters" throughout their life span. The studies, there- 

 fore, in this field bear directly upon the problem of fish produc- 

 tion. 



Plankton estimations for the period of the survey cover only the 

 the largest of the deep lakes (Seneca and Cayuga) and the largest 

 shallow lake, Oneida. The values for these lakes are made graphi- 

 cally apparent in the charts (1-8, p. 144), values which represent a 

 stupendous amount of counting of microscopic organisms. A fur- 

 ther understanding is gained by direct comparison of plankton 

 quantities as shown in chart 9. 



Associated with plankton studies, however, and requisite for any 

 true interpretation of the productive capacity of the lakes, are 

 various complex problems related to the abundance of the rooted 

 vegetation, and to far reaching chemical, physical and physiological 

 relations which play their part in the "going concern" of any lake. 



The Lamprey, a Pest of Lake Fishes. — In the several large 

 lakes of the Oswego watershed the depredations of the lake lamprey 

 occur with menacing frequency among the food and game fish. 

 They are blood suckers, attacking fish only and their extraordi- 

 narily rapacious habits in this respect call forth discussion of ways 

 and means of combating them. 



Fortunately there is at hand in the researches of Professor S. H. 

 Gage of Cornell University, an authority on the lamprey, such com- 

 pleteness of knowledge of the life history of this parasite that 

 methods of control are clearly indicated. Through the courtesy and 

 generous cooperation of Professor Gage the survey report contains 

 the important chapter on the lamprey including in the paper both 

 the life history and the economics of this serious pest of our lake 

 fishes. 



Papers by Specialists on the Survey.— The data collected in 

 the several lines of inquiry are presented in full in the following 

 sections dealing with : 



(1) Stocking policy for the Oswego river system. 



(2) The Finger lakes fish problem. 



(3) Carp control studies in Oneida lake. 



(4) Fishes of the Oswego river system. 



(5) Chemical investigation of the Oswego watershed. 



(6) Biological studies of polluted waters in the Oswego water- 



shed. 



(7) Plankton studies of Cayuga, Seneca and Oneida lakes. 



(8) Iiife history and economics of the lampreys of New York 



State. 



(9) A quantitative study of the fish food supply in selected areas. 



