32 Ij. S. BUREAU OF FISHERIES 



in Cook Inlet, Alaska. Surveys of the local conditions were made 

 and data obtained for the determination of age, growth, size at 

 sexual maturity, and the date of the breeding season. Subsequently 

 data for comparison were obtained from the Washington coast. 

 This field work will be continued and extended during the current 

 sunmier by Doctor Weymouth with the assistance of H. C. Mc- 

 Millin, scientific assistant, who during the past year has been in- 

 vestigating the razor clam for the State of Washington. These in- 

 vestigations have been undertaken for the purpose of securing in- 

 formation on which to base regulations for the conservation of the 

 rapidly expanding fishery. The data already secured have been 

 used in preparing the regulations now in force. 



The more important findings and the problems that require solu- 

 tion may be briefly summarized. Preliminary surveys of the density 

 of population on the beds in the older regions and their history in- 

 dicate that these have about reached their full commercial develop- 

 ment and that more intense fishing is unwise. Data from the ex- 

 amination of the shells have made it possible to picture the growth 

 in a number of localities. Among other interesting facts brought 

 out is that growth is much more rapid on the Washington coast, 

 and that therefore a marketable size is reached in one-half to 

 two-thirds the usual time. The set of young on the Alaskan beds 

 was far inferior to that on the Washington coast, and this has ap- 

 parently been the case in past years. The comparison of growth 

 for many localities in this widely distributed species shows an in- 

 teresting relation between growth and latitude and will probably 

 throw light on the question of local races. 



In consequence of the slower growth and less abundant spawn- 

 ing of the Alaskan clam, the experience on the Washington coast 

 is no safe guide to the intensity of the fishing that the beds of 

 Alaska will endure. If, however, the intensity of the fishing is 

 wisely regulated, and a breeding reserve assured by a proper size 

 limitl there is no reason that clam canning should not be a per- 

 manent and valuable industry on many Alaskan beaches. 



A preliminary report has been submitted and a more compre- 

 hensive report is in course of preparation. 



FRESH-WATER MUSSELS 



The investigations bearing on the life histories and artificial propa- 

 gation of fresh-water mussels, have been carried on as usual by the 

 staff of the biological laboratory at Fairport, Iowa. Mussel surveys 

 were made in Lake Pepin, on the Mississippi River between 

 Dubuque and Keokuk, and in Arkansas on the Wliite, Black, and St. 

 Francis Rivers. The Lake Pepin survey was one of a series of 

 annual mussel surveys in that lake, made with the object of deter- 

 mining the effect of the yearly propagation of the fat mucket 

 {Lampsilis luteola) upon the mussel population of the lake, and to 

 learn more accurately the effect of the closure of various sections of 

 the lake for four-year periods on the quantity of mussels available 

 for the fishery. It is believed that one or two more surveys will be 

 necessary before conclusions in either case can be reached. In 

 Arkansas the survey was made with the purpose of assisting that 



