REPORT OF THE COMMIRvSIONER OF FISHERIES. 21 



dncinfr streams Avill join in this movement before the resources be- 

 come too seriously (lo[)lete(l. 



In the course of the fiscal year there Avas issued a document de- 

 scribinfj in detail the commercial fresh-water mussels, the implements 

 and practices of the mussel fishery, and the machinery and methods 

 of manufacture of buttons from the shells. There has also been com- 

 pleted and submitted for publication a «ieneral account of the natural 

 history and i)ropa<iation of the mussels. These ])apers are issued in 

 response to a <j:eneral demand for the varied information contained 

 in them, and with a view to disseminating^ such knowled<rc of the 

 resources and industries and of the conditions of their perpetuation 

 as will stimulate the adoption of measures and practices wdiereby un- 

 necessary waste may be avoided and the future as well as the present 

 may be served. 



MISCELLANEOUS STUDIES. 



Investio:ation of the reddening of salt fish, which causes large an- 

 nual losses to fish packers, has been continued and some definite con- 

 clusions are now possible. It has been ascertained that the discolora- 

 tion is due to the growth of at least two organisms, one of which 

 under appropriate conditions is characteristically red and the other 

 pink. The simultaneous growth of these organisms results in the 

 production of various shades of color. The organisms evidently have 

 their origin in the imported sea salt which is so extensively used in 

 the fishing industry. The conditions of growth of the causative 

 agents have been pretty well determined, and experiments are under 

 way to determine the means of eradication. 



In response to solicitations from the trade that domestic sources 

 be found for a vegetable gelatin such as is required for the satis- 

 factory packing of certain fish products in cans, the Bureau has 

 conducted an inquiry into the properties of gelatin derived from the 

 seaweeds of the New England coast. A gelatinous extract from the 

 common " Irish moss " of that coast, when properly prepared, was 

 found to meet the requirements. It has been thought advisable to 

 carry the investigation further and to ascertain the possibilities of 

 developing domestic sources for agar-agar and other valuable 

 gelatins of commerce now imported. 



SCIENTIFIC WORK OF THE VESSELS. 



The steamers Alhati'oss and Fish Hawk, which had been surren- 

 dered to the Navy Department for the period of the war, were re- 

 turned to service in the interests of the fisheries during the early 

 part of the fiscal year. 



For the present it is intended to retain the Albatross in the Atlan- 

 tic, from which she has been absent for a period of more than 30 

 years. Her work up to the close of the fiscal year consisted in one 

 cruise to the south as far as the Yucatan Channel and another cruise 

 along the northeast coast and into the Gulf of Maine. Oceano- 

 graphic studies and fishery trials were features of the cruises. The 

 Albatross is now better equipped than ever before for practical 

 fishing operations, and it is expected that as soon as the crew is 

 properly trained and a suitable scientific staff can be found the 

 vessel will make even more substantial contributions to the w^elfare 

 of the fisheries than it has in the past. 



