REPORT OF COMMISSIONER OF FISH AND FISHERIES. XLVII 



over the bed of the river iu front of Georgetown aud in lesseuiug quantity 

 as far down as the limits of the District extend. Its general distribu- 

 tion over the bed of the river may, and doubtless does, affect unfavora- 

 bly the conditions of life for all those minute forms of life which have 

 their nidus on the bottom, and which furnish the food of forms alike 

 minute, which float or swim in the water above, and which aftbrd ap- 

 propriate sustenance to the young shad, herring, striped bass, »&c. The 

 pollution of the water may not exert a direct effect in driving the larger 

 fish from the river, yet indirectly, by modifying unfavorably the con- 

 ditions of life at the bottom, may, by destroying their food, render im- 

 possible the development and growth of the embryo fish, which must be 

 nurtured in this area in numbers sufficient to compensate the annual 

 drain made bj^ the river fisheries. 



In connection with the legislation now i)ending to limit or restrict 

 net fishing in the District waters, it is deemed important to prohibit the 

 discharge of waste products from the gas factories into the river, and I 

 liave so advised the Board of Hoifclth. The measures of legislation pro- 

 l)osed and iiendiug, if enacted into law, will doubtless exert an impor- 

 tant conservative influence upon the shad and herring fisheries of the 

 Potomac. 



24. — SPECIES OF FISH CULTIVATED AND DISTRIBUTED IN 1884. 



The species of fish and invertebrates receiving the attention of the 

 Commission during the year, with the exception of the addition of a few 

 of more or less interest, are the same as lieretofore. Work has been 

 l)rosecuted on a large scale in regard to only a few species ; those receiv- 

 ing special attention, in addition to the several varieties of Salmonidd, 

 are the shad, the carp, and the goldfish. The scale of the operations 

 on which the work has been conducted has, however, iu many cases 

 been much greater than heretofore; not only a larger number having 

 been hatched out, but the area of distribution greatly extended. 



The following is a list of the species included : 



(t. The Codfish {Gudu.s mon-hua). 

 . /). The Rockfish or Striped Bass {Eoccun lincatas). 



V. The Whitefish (Coreijoiuis dupeiformis). 

 (I. The Moranke {Coretjoniis albtila). 



e. The Grayling (Thijinallus tricolor). 



f. The Brook Trout ( Salvelhms fontinalis) . 

 (f. The Lake Trout (Salvelinus nawaycush). 

 Ii. The Saibling (Salmo salvelinus). 



). The California, Rainbovr, or Mountain Trout {Salmo irideus). 

 J. The Atlantic or Penobscot Salmon (Sabno salar). 

 k. The Schoodic or Landlocked Salmon {Salmo salar subsp. scbago)^ 

 I. The Brown or Europeaxi Trout (Salmo fario). 



VI. The Loch Leven Trout (Salnw lereiteiisis). 



71. The Quinnat or California Salmon {Oncorhnncjitis chouicha). 



0. The Shad {('lupea sapidissima). 



2>. The Hiver Herring {I'omohbus wstlvalis). 



