PIKE-PERCH PROPAGATION IN NORTHERN 



MINNESOTA. 



By Eben W. Cobb. 



Northern Minnesota is supplied by nature with the best 

 conditions for pike-perch to be found. Here are the head 

 waters of three great water systems with literally thousands 

 of clear lakes, many of which are of a large size. Much of 

 this territory is wild and will doubtless remain so for a long 

 time. 



Pollution except in Rainy River, is a thing unknown and 

 only the acts of man interfere with the fish. Once the 

 supply of pike-perch seemed inexhaustible, but where good 

 roads have been opened and the summer tourists have come 

 in there has been a rapid decrease in the number of fish and 

 in som.e instances the depletion has been great enough to 

 cause poor fishing. The vicinity of Detroit may be taken as 

 an example. Here is one of the very best lake regions in 

 the state. Within a comparatively short period of time, the 

 pike-perch, which were here in seemingly countless numbers, 

 have been reduced to such an extent, that those whose pur- 

 pose it is to find pike fishing pass on to other waters. 



The taking of pike-perch eggs by our state at one time, 

 was carried on for the purpose of securing eggs, that fry 

 might be furnished to lakes throughout the more thickly 

 settled portions of the state. As it became apparent that 

 the supply of these fish could be m-aintained only by looking 

 first after the large and productive lakes throughout the 

 northern portions of the state, a definite programme was 

 formed with this object in view. The building of field 

 stations, which were in reality hatcheries, v/as undertaken. 

 These were located at or near the spawning grounds and in 

 them were placed the eggs as they were taken from day to 

 day. A large part, and in many cases all, of the resulting 

 fry were returned to the waters from which the spavv^n was 

 secured. In some instances spawn was taken to the other 

 hatcheries. The primary object was to care for the spawn 

 producing lakes but it is interesting to note that the average 

 hatch where eggs v/ere placed in jars without shipment ran 

 about 25 'a ahead of the hatch where shipment takes place 

 in the green stage. This will be of interest to those studying 

 the causes of losses in pike-perch eggs. We also feel that 

 there is a saving in numbers due to the direct planting but 



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