74 



REPORT OF THE COMMISSIONER OF FISHERIES. 



winds were quite prevalent during the hatching season, they were not 

 from a direction that causes extremely roily water in the harbor. 

 The losses during the incubation period were therefore light as com- 

 pared with some years when more favorable conditions have been 

 encountered, and from the 856,002,000 eggs reahzed 678,770,000 fry, 

 or 79 per cent, were hatched. 



RESCUE OF FISHES FROM OVERFLOWED LANDS. 



The rescue of food fishes from temporary ponds and sloughs border- 

 ing the Mississippi and Illinois Kivei's was vigorously prosecuted in 

 the fields formerly operated near Bellevue and North McGregor, 

 Iowa; Homer, Minn.; La Crosse, Wis.; Meredosia, 111.; and Friar 

 Point, Miss. ; and a new collecting base was estabhshed at Galena, 111., 

 the returns from which were very encouraging. 



Warm weathor in August and earlj^ ice formations in November 

 shortened the season in the upper Mississippi River, while operations 

 at Meredosia v/ere hampered by high-water stages in the Illinois River 

 during July and August, at the very time when this work can usually 

 be prosecuted to best advantage. Another unfavorable feature at 

 this station was the excessive heat almost daily in July, which made 

 the handling o? the rescued fish very difficult. Owing to these con- 

 ditions the aggregate collections of 8,818,160 at all points were about 

 3,000,000 less than those of the preceding year. As in past years, the 

 majority of the rescued fishes were returned to the main river chan- 

 nels, and a limited number were used to supplement the black-bass 

 distributions from the pond-fish cultural stations of the Bureau. 



Tlie salvaging of fishes from the overflowed lands can and should 

 be very ^eatly extended throughout the Mississippi Basin. The 

 comparatively slight attention given to the matter by the States 

 emphasizes the necessity of Federal aid in ameliorating or preventing 

 the enormous annual losses to which the best food fishes of the region 

 are subject. 



PLANTS IN CONNECTION WITH FISH-CULTURAL EXPERIMENTAL WORK. 



In addition to the work of mussel propagation carried on by the 

 fisheries biological station at Fairport, Iowa, experiments of a prac- 

 tical nature relating to the propagation and rearing of useful fishes 

 are also conducted. The result is the production of large numbers of 

 fishes, not all of which are required in experimental work, the surplus 

 being liberated in public watere, usually in the vicinity of Fairport. 

 The following table gives the number of each species distributed in 

 1917 and the age at which planted. These figures are included in the 

 general tables of distribution which appear elsewhere. 



