U.S. Department 
of Commerce 
William M. Daley 
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 
Sr 4T 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 C15700, Seattle, WA 
98115-0070. Periodicals postage is paid 
at 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 en- 
tirely, reference to source is appreci- 
ated. 
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: $32.00 domestic 
and $40.00 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 University of Idaho, Hagerman 
Dr. Richard D. Methot National Marine Fisheries Service 
Dr. Theodore W. Pietsch University of Washington, Seattle 
Dr. Joseph E. Powers National Marine Fisheries Service 
Dr. Harald Rosenthal Universitat Kiel, Germany 
Dr. Fredric M. Serchuk 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. 
