Culler. — Fish Cultural Work in Mississippi Valley. 187 



do not react promptly to the falling waters and enormous num- 

 bers are cut off and become permanently landlocked. 



The lakes and sloughs left by the falling waters are of various 

 sizes and depths; some of them dry up in a few days or weeks, 

 while others become so shallow that the fish will freeze during 

 the winter months. The shallower pools freeze solidly, while in 

 the deeper ones the fish are so highly concentrated that death by 

 smothering is inevitable, even though the pool does not freeze 

 solid to the bottom. From these lakes and sloughs millions of 

 fishes of all warm water species found in the Mississippi River 

 are taken by the rescue crews and transferred to the main channel 

 of the river or to a running slough, a small percentage being held 

 for distribution to other waters. 



The need of some sort of salvage work has long been recog- 

 nized and the first attempts to save a few of the stranded fishes 

 occurred in the late nineties. It is only in recent years, however, 

 that the work may be considered as approaching a point commen- 

 surate with the need. In the past the lack of funds and trained 

 personnel has worked a great disadvantage; however, Congress 

 at the last session recognized the needs of the situation by provid- 

 ing a suitable personnel so that this important work can be further 

 extended in the future. 



The territory now covered extends from Prescott, Wis., on the 

 north to Savanna, 111., on the south; and the experimental work is 

 being carried on in the vicinity of Rock Island to determine whether 

 sufficient numbers of fish can be rescued at reasonable cost. Head- 

 quarters for the work are at Homer, Minn., with sub-stations at 

 La Crosse, Wis., and Marquette and Bellevue, Iowa. These points 

 represent the centers of the most prolific fields. 



Some lakes and sloughs are not as productive as others, some 

 having but a few thousand fish while others have large numbers. 

 As an example of large numbers that are sometimes caught in 

 one lake, the crew at Lynxville, Wis., seined a large shallow lake, 

 the maximum depth of which was 28 inches, and carried 182 tubs 

 of miscellaneous fish to the main channel. This represented a 

 saving of 1,250,000 fish, or an average of approximately 7,000 per 

 tub. These numbers seem large, but when it is taken into con- 

 sideration that small carp an inch long will run approximately 

 1,200 per quart and small bullheads from 1,800 to 2,000 per quart. 



