16 REPORT OP THE COMMISSIONER OF FISHERIES. 



bottoms, and a preliminary inquiry has been made to determine the 

 most profitable and practicable assistance feasible with the resources 

 available to the Bureau. 



Cooperation with the Coast and Geodetic Survey and the Mary- 

 land Shell Fish Commission in the survey of the oyster beds of Mary- 

 land, pursuant to an act of Congress, has been continued, and the 

 field work will be completed early in the next fiscal year. It is be- 

 lieved that the Bureau will have discharged all of its obligations in 

 this connection prior to the end of the fiscal year 1911. 



The experiments in the fattening of oysters at Lynnhaven Bay, 

 Virginia, have produced better results than for several years past. 

 During a period when practically no fat oysters could be obtained 

 from the open waters of the bay the experimental claire was regularly 

 producing oysters of very fine quality. In this connection the Bu- 

 reau is conducting investigations of the food and feeding of oysters 

 which have already developed some unexpected results, throwing 

 light on practical problems confronting the oyster grower. Some 

 minor modifications of the claire were made near the end of the fiscal 

 year, and it is hoped that it will be possible to fatten oysters earlier 

 in the season than has been possible heretofore. 



PEARL-MUSSEL INVESTIGATIONS. 



The Bureau has continued its investigations of the pearl-mussel 

 beds of the Mississippi Valley, the material depletion of which has 

 seriously threatened the prosperity of an important industry of that 

 region. With the aid of persons connected with various educational 

 institutions of the States principally interested, field parties were 

 established for the examination of various streams in Virgina, West 

 Virginia, Michigan, Indiana, Illinois, Kentucky, Tennessee, Arkansas, 

 Missouri, and Oklahoma. The habits, distribution, abundance, and 

 commercial availability of the mussels found in the several localities 

 were studied with the view of opening new sources of supply for the 

 manufacturers of pearl buttons and for the purpose of laying, a foun- 

 dation for the protection, conservation, and improvement of the 

 existing beds. 



Owing to the severity of the weather during the winter, progress 

 in the erection of the biological station at Fairport, Iowa, authorized 

 by Congress near the close of the preceding fiscal year, was less rapid 

 than was desired, but on the improvement of conditions in the spring 

 construction work went on more rapidly, and at the close of the fiscal 

 year mussel-propagating operations were being conducted on a scale 

 promising to yield some practical results. As was pointed out in the 

 preceding report of the Bureau, this station is designed for the study 

 of problems relating to the general fisheries and aquatic biology of 



