U.S. Department 

 of Commerce 



Ronald H. Brown 

 Secretary 



National Oceanic 

 and Atmospheric 

 Administration 



D. James Baker 

 Under Secretary for 

 Oceans and Atmosphere 



National Marine 

 Fisheries Service 



Rolland A. Schmitten 

 Assistant Administrator 

 for Fisheries 



J ^r ES o* * 



The Fishery Bulletin (ISSN 0090-0656) 

 is published quarterly by the Scientific 

 Publications Office, National Marine 

 Fisheries Service, NOAA, 7600 Sand 

 Point Way NE, BIN CI 5700, Seattle, WA 

 98115-0070. Second class postage is paid 

 in Seattle, Wash., and additional offices. 

 POSTMASTER send address changes for 

 subscriptions to Fishery Bulletin, Super- 

 intendent of Documents, Attn: Chief, 

 Mail List Branch, Mail Stop SSOM, 

 Washington, DC 20402-9373. 



Although the contents have not been 

 copyrighted and may be reprinted entire- 

 ly, reference to source is appreciated. 



The Secretary of Commerce has deter- 

 mined that the publication of this peri- 

 odical is necessary in the transaction of 

 the public business required by law of 

 this Department. Use of funds for 

 printing of this periodical has been ap- 

 proved by the Director of the Office of 

 Management and Budget. 



For sale by the Superintendent of 

 Documents, U.S. Government Printing 

 Office, Washington, DC 20402. Subscrip- 

 tion price per year: $27.00 domestic 

 and $33.75 foreign. Cost per single issue: 

 $13.00 domestic and $16.25 foreign. See 

 back page for order form. 





Scientific Editor 

 Dr. John B. Pearce 



Editorial Assistant 

 Kimberly T. Murray 



Northeast Fisheries Science Center 

 National Marine Fisheries Service, NOAA 

 1 66 Water Street 

 Woods Hole, Massachusetts 02543-1097 



Editorial Committee 



Dr. Andrew E. Dizon National Marine Fisheries Service 



Dr. Harlyn O. Halvorson University of Massachusetts, Dartmouth 



Dr. Ronald W. Hardy National Marine Fisheries Service 



Dr. Linda L. Jones National Marine Fisheries Service 



Dr. Richard D. Methot National Marine Fisheries Service 



Dr. Theodore W. Pietsch University of Washington 



Dr. Joseph E. Powers National Marine Fisheries Service 



Dr. Fredric M. Serchuk National Marine Fisheries Service 



Dr. Tim D. Smith National Marine Fisheries Service 



Managing Editor 

 Sharyn Matriotti 



National Marine Fisheries Service 

 Scientific Publications Office 

 7600 Sand Point Way NE, BIN C 1 5700 

 Seattle, Washington 98115-0070 





The Fishery Bulletin carries original research reports and technical notes on investiga- 

 tions in fishery science, engineering, and economics. The Bulletin of the United States 

 Fish Commission was begun in 1881; it became the Bulletin of the Bureau of Fisheries 

 in 1904 and the Fishery Bulletin of the Fish and Wildlife Service in 1941. Separates 

 were issued as documents through volume 46; the last document was No. 1103. Begin- 

 ning with volume 47 in 1931 and continuing through volume 62 in 1963, each separate 

 appeared as a numbered bulletin. A new system began in 1963 with volume 63 in 

 which papers are bound together in a single issue of the bulletin. Beginning with 

 volume 70, number 1, January 1972, the Fishery Bulletin became a periodical, issued 

 quarterly. In this form, it is available by subscription from the Superintendent of 

 Documents, U.S. Government Printing Office, Washington, DC 20402. It is also 

 available free in limited numbers to libraries, research institutions, State and Federal 

 agencies, and in exchange for other scientific publications. 



