48 REPOKT OF THE SECRETARY. 



As in previous years, the operatioDs have been carried on under two 

 distinct divisions: first, the inquiry into the condition of the American 

 fisheries; and secondly, the multiplication of useful food-fishes in the 

 rivers and lakes of the United States. 



The first division embraces a critical examination into the physical 

 and biological character of the waters, such as the determination of 

 their temperature in different seasons, their currents, their chemical 

 composition, the character of the bottom, and the precise nature of the 

 animal and vegetable life occurring therein, with their mutual relations; 

 as also the influences which may tend to affect the abundance and the 

 distribution of the fish in different seasons, whether by natural causes, 

 artificial impediments or obstructions, or by excessive fishing. Work 

 in this direction has been conducted since 1871, and has resulted in 

 supplying a minute and satisfactory knowledge of the character of the 

 coast and off-shore portions of the United States, from the Bay of Fundy 

 to Long Island Sound, and other portions of the sea-coast and of the 

 lakes have been investigated in a less elaborate manner. 



The operations in regard to the propagation of food-fishes relate espe- 

 cially to the introduction of California salmon, Atlantic salmon, land- 

 locked salmon, and whitefish into new waters, or their multiplication in 

 those that have been depleted. Special attention, also, in later years, 

 has been directed to the European carp, a well known and favorite 

 domesticated fish, and promising to be an important addition to the 

 food resources of the United States. 



The usual operations of the Fish Commission, in its maritime work 

 duriug 1877, were somewhat modified by the attendance of Professor 

 Baird on the International Fishery Convention on the part of Great 

 Britain and the United States, at Halifax, by the request of the Secre- 

 tary of State. 



Under the law of Congress, which directs all needed aid to be fur- 

 nished, as far as practicable, to the United States Fish Commission in 

 its varied operations, by the executive departments of the government, 

 the Secretary of the iJvavy has for several years supplied a steamer, 

 completely equipped for use, and in the season of 1877 a much larger 

 vessel than nsual was detailed at the request of the Secretary of State; 

 this was the tug Speedwell, an iron propeller of 310 tons and of great 

 stanchness, and thoroughly fitted for her work. She was equipped for 

 the special service at the navy-yard in Portsmouth, X. H., under the 

 direction of Commodore Guest, and the scientific apparatus formerly 

 used on board the United States steamer Blue Light was transferred to 

 her at New Loudon. She was commanded by Lieutenant-Commander 

 A. G. Kellogg, with Dr. T. H. Sheets as surgeon, and Mr. A. V. Zane 

 as engineer. The vessel reported for duty on the 31st of July, at Salem, 

 at which point Professor Baird had been stationed for a month, engaged 

 in the preliminary work of the commission prior to proceeding to Hali- 

 fax. This consisted, in part, in the collection of statistical information 



