. The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder. Oceanography Bering New Alaska surf clam resource 1211 TABLE 67-2 Catch rates and mean shell-length size-composition oi Spisula polynyma at 13 production fishing sites along the north coast of the Alaska Peninsula, 1978. Fishing was conducted with a hydraulic clam harvester m wide equipped with a 5-cm ring collecting bag Production Survey Fishing Total Catch/Hour Mean shell length site no. block no. effort (h) catch (kg) kg bu mm 1 44 686 411 124 2 45 855 611 16.
. The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder. Oceanography Bering New Alaska surf clam resource 1211 TABLE 67-2 Catch rates and mean shell-length size-composition oi Spisula polynyma at 13 production fishing sites along the north coast of the Alaska Peninsula, 1978. Fishing was conducted with a hydraulic clam harvester m wide equipped with a 5-cm ring collecting bag Production Survey Fishing Total Catch/Hour Mean shell length site no. block no. effort (h) catch (kg) kg bu mm 1 44 686 411 124 2 45 855 611 124 3 50 1,667 675 107 4 57 8,100 731 103 5 57 2,326 894 111 6 57 7,327 801 119 7 56 1,592 870 112 8 57 2,154 1,290 117 9 59 1,379 919 123 10 59 8,289 635 112 11 60 725 711 120 12 60 2,297 907 123 13 62 2,485 1,147 108 All sites 39,882 Mean 815 Mean 113 Growth patterns and parameters were determined from means of the observed lengths-at-age obtained from the composite year-classes represented and separately from mean lengths-at-age determined from back-measured growth rings. Thus, growth from the composite year-classes comprising the 1977 and 1978 stock was compared with the generalized growth pattern which has persisted over the past 19 years. It is not recommended that growth parameters resulting from back-measured age rings be used directly for management, but this comparison pro- vides valuable insight into growth patterns over past years when no data are available. Because variation in age-range affects compara- bility of parameters (Hirschhom 1974) and growth rings were difficult to read beyond 19 years of age, curve fits were computed both with fits over a standardized age-range of 3-19 and with an artificial data point () added on the assumption that at age 0, length is near 0 (Alverson and Carney 1975). Age increments by the fraction of a year
Size: 1771px × 1412px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionamericana, bookdecade1980, bookspo
