U.S. Department 

 of Commerce 



Carlos M. Gutierrez 



Secretary 



National Oceanic 

 and Atmospheric 

 Administration 



Vice Admiral 



Conrad C Lautenbacher Jr., 



USN (ret.) 



Under Secretary for 

 Oceans and Atmosphere 



National Marine 

 Fisheries Service 



William T. Hogarth 



Assistant Administrator 

 for Fisheries 



<^ T0Fe % 





The Fishery Bulletin (ISSN 0090-0656) 

 is published quarterly by the Scientific 

 Publications Office, National Marine Fish- 

 eries Service, NOAA, 7600 Sand Point Way 

 NE, BIN C15700, Seattle, WA 98115-0070. 

 Periodicals postage is paid at Seattle, WA, 

 and at additional mailing offices. POST- 

 MASTER: Send address changes for sub- 

 scriptions to Fishery Bulletin, Superin- 

 tendent of Documents, Attn.: Chief, Mail 

 List Branch, Mail Stop SSOM, Washing- 

 ton, DC 20402-9373. 



Although the contents of this publica- 

 tion have not been copyrighted and may 

 be reprinted entirely, reference to source 

 is appreciated. 



The Secretary of Commerce has deter- 

 mined that the publication of this peri- 

 odical is necessary according to law for 

 the transaction of public business of this 

 Department. Use of funds for printing of 

 this periodical has been approved 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: $55.00 domestic and 

 $68.75 foreign. Cost per single issue: 

 $28.00 domestic and $35.00 foreign. See 

 back for order form. 



Scientific Editor 



Norman Bartoo, Ph.D. 



Associate Editor 



Sarah Shoffler 



National Marine Fisheries Service, NOAA 

 8604 La Jolla Shores Drive 

 La Jolla, California 92037 



Managing Editor 



Sharyn Matriotti 



National Marine Fisheries Service 

 Scientific Publications Office 

 7600 Sand Point Way NE, BIN C15700 

 Seattle, Washington 98115-0070 



Editorial Committee 



Harlyn O. Halvorson, Ph.D. 

 Ronald W. Hardy, Ph.D. 

 Richard D. Methot, Ph.D. 

 Theodore W. Pietsch, Ph.D. 

 Joseph E. Powers, Ph.D. 

 Harald Rosenthal, Ph.D. 

 Fredric M. Serchuk, Ph.D. 

 George Waiters, Ph.D. 



University of Massachusetts, Boston 

 University of Idaho, Hagerman 

 National Marine Fisheries Service 

 University of Washington, Seattle 

 National Marine Fisheries Service 

 Universitat Kiel, Germany 

 National Marine Fisheries Service 

 National Marine Fisheries Service 



Fishery Bulletin web site: www.fishbull.noaa.gov 



The Fishery Bulletin carries original research reports and technical notes on investigations in 

 fishery science, engineering, and economics. It began as the Bulletin of the United States Fish 

 Commission 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. Beginning 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. 



