8 Conservation Department 



normal fauna and flora are completely replaced by pollutional 

 forms and by g-aseous or other conditions inimical to fish life. 

 Mention is made of a notable instance in which an industry using 

 the stream for dis])osal has develo])ed and installed a ]:>recipitation 

 l)lant for the partial recovery of wastes before emptying them into 

 the stream. A useful tabulation ])rovides data of im])ortance to 

 each community in which pollution studies have been made. 



Fish Population. — In studying the s])ecies of fish an effort has 

 been made to secure re])resentatives of the entire stream system 

 together with a stud}^ of their food i)references and the conditions 

 favoring their natural development. Sixty-six different species 

 are represented. Twenty-six of these fall in the group of food 

 and game fishes, twenty-three belong iu the minnow family, and 

 the others represent miscellaneous sj)ecies. Of the minnows five 

 are of excellent bait variety and one of them, a mud-eating species, 

 possesses important qualities of fish cultural value. The carp, 

 contrary to expectation, is unimportant above Rochester Falls. 



Fresli light is thrown on various ])rob]ems concerned with fish 

 distribution as for exam))le the fish associations of the game and 

 otlier fishes, the dominating species under certain conditions of 

 l)ollution and the adjustments to temperature. 



Colored Plates of Minnows. — All efforts to increase the pro- 

 duction of food and game fish are closely linked with an under- 

 standing of this group of fishes. They contribute fundamentally 

 to the food supi)ly of other fishes, they are competitors or non- 

 comi)etitors. Some of tliem are imjwrtant enemies of fish life. 

 Of the twenty-two species found in the Genesee system less than 

 a half dozen are known familiarly and these only because tliey are 

 attractive as bait. Quite generally tlu^ |)opular bait fishes are con- 

 fined to a few s])ecies only. Doubtless others are valuable or liave 

 |)ossibilities of fish cultural value. These are important questions 

 to consider as interest in the sport of fishing is expanding, and 

 questions on restrictions and vending of minnows are receiving 

 attention in conservation ]irograms. 



The colored plates will help to arouse greater interest in minnow 

 life. A dry order of facts about minnows is not adapted for ])0])U- 

 lar consum])tion. It is stimulating and it engages the imagination, 

 for exam])le, to point out that the typical brook-trout-stream min- 

 now is the pearl minnow sharing with the trout the coldest watei's. 

 And that another com))etitor with the front, though in the less 

 cold waters, is the red-sided minnow. It is important to know 

 that the minnow associate of the small luout lied bass in the swift 

 waters of the larger streams is Ihe long-nosed dace, an algal eater 

 in part and not a comi)etitor with llic bass. The beautiful satin-fin 

 is a tolerant form and a good acpuii-ium minnow. The l)lack-nosed 

 dace, an ubiquitous ininnow of the smaller tributaries, is one of 

 the most tolerant of all the minnows ()ccn|)ying waters in clea?i 

 streams oi- in heavily |)ol luted ones. The common shiner is one of 

 the best of bait minnows. The blunt-nosed minnow is a species with 



