FISH RESCUE OPERATIONS 



By C. F. Culler 

 Superintendent, U. S. Bureau of Fisheries, Homer, Minn. 



Perhaps no branch of the fish-cultural work of the 

 Bureau of Fisheries has attained more rapid development 

 during the past few years than that addressed to the res- 

 cue of fishes from the overflowed lands bordering the 

 Mississippi River. The development and growth of the 

 work is manifested not only by the ever-increasing num- 

 bers of food and game fishes rescued each season, but it is 

 also marked by a decreasing unit cost of production. 



Several times each year the Mississippi overflows its banks, 

 but it is the annual freshet known as the June rise that is of 

 greatest importance to the fisheries. As the river rises the 

 adjacent lowlands are submerged. The quiet backwaters thus 

 formed provide very attractive spawning areas for the food 

 and game fishes indigenous to the river. The eggs are laid 

 under conditions favorable to their development and the young 

 fish attain a rapid growth before the freshet begins to subside. 

 At this time the adult fish find their way to safety in the main 

 channel, but the young do not react promptly to the falling 

 waters, and enormous numbers are cut off and become per- 

 manently landlocked. 



The pools and lakes left by the falling waters are of var- 

 ious sizes; some of them may become dry in a few days or 

 weeks, while others may persist into the winter months. In 

 either event, the fish remaining in them are doomed to cer- 

 tain destruction unless a rescue party comes to their aid and 

 returns them to the open waters of the river. If any of the 

 fish are able to survive the frightful conditions that exist in 

 these landlocked pools, and which as the summer advances 

 become more aggravated, the arrival of cold weather is sure 

 to end the story. The shallower pools freeze solidly, while 

 in the deeper ones the fish are so highly concentrated that 



