ANNUAL PRODUCTION OF EVISCERATED BODY WEIGHT, FAT, AND 



GONADS BY PACIFIC HERRING, CLUPEA HARENGUS PALLASI, 



NEAR AUKE BAY, SOUTHEASTERN ALASKA 



Jay C. Quast 1 



ABSTRACT 



Pacific herring, Clupea harengus pallasi, grow according to the constant-proportion growth model, which 

 requires that yearly growth in body length be a constant proportion of growth during the previous year. 

 Herring have one or two growth stanzas (periods of constant-proportional growth) in the eastern Pacific 

 Ocean and eastern Bering Sea, and grow faster in the eastern Bering Sea than in the northeastern Pacific 

 Ocean. 



With growth, total and eviscerated body weights of fresh Auke Bay herring bear an exponential 

 relationship to body length (BL) that is slightly greater than cubic, and evisceration does not lower variabili- 

 ty in length-weight relationships. With growth, an increasing part of the annual product (growth plus 

 gonads) is partitioned into gonads so that in the largest fish most of the annual product is gonads. The 

 annual product is constantly proportional to BL through ages 2-6 and also through ages 9-12, but the 

 proportion is considerably smaller in the 9- to 12-yr-old fish. The two differing proportions may indicate 

 that young and old Auke Bay herring occupy slightly different feeding niches and that the trophic en- 

 vironment in the Auke Bay vicinity may not support the older fish as well as the younger. 



Pacific herring spawn in April or May in the Auke Bay vicinity, as zooplankton density rapidly in- 

 creases to its peak in June. The time of spawning seems optimal for rapid building of fat reserves and 

 feeding of newly hatched larvae. 



Pacific herring, Clupea harengus pallasi, range off 

 western North America, from the Chukchi Sea to 

 San Diego, CA, and have been commercially ex- 

 ploited over the entire range (Rounsefell 1930; 

 McLean and Delaney 1978; Spratt 1981). Pacific 

 herring usually occupy extensive reaches of coast, 

 from tens to hundreds of miles, and populations are 

 particularly dense around the Alexander Archi- 

 pelago of southeastern Alaska and the archipelago 

 off British Columbia (from charts or fisheries maps 

 in Rounsefell 1930, McLean and Delaney 1978, and 

 Spratt 1981). Yet, even where dense, populations 

 can be locally distinctive in vertebral number and 

 spawning time (Rounsefell and Dahlgren 1935; 

 Hourston 1980). 



Pacific herring have been commercially harvested 

 in Alaska since the late 1800's (Rounsefell 1930), 

 principally for reduction to meal and oil. Herring 

 were also pickled, starting in 1900, but the industry 

 never became large and declined in the 1920's. A 

 fishery for Pacific halibut, Hippoglossus stenolepis, 

 bait had a similar rise and decline. The reduction 



Northwest and Alaska Fisheries Center Auke Bay Laboratory, 

 National Marine Fisheries Service, NOAA, P.O. Box 210155, Auke 

 Bay, AK 99821; present address: 1565 Jamestown Street S.E., 

 Salem, OR 97302. 



Manuscript accepted December 1985. 

 FISHERY BULLETIN: VOL. 84, NO. 3, 1986. 



fishery ended in the 1960's, and the principal fishery 

 for Pacific herring in Alaska now is sac roe, which 

 is exported to Japan. 



The biology of Pacific herring in Alaska has not 

 been thoroughly described. The study by Rounse- 

 fell (1930) is the most comprehensive work, and 

 Rounsefell and Dahlgren (1935) separated stocks in 

 southeastern Alaska on the basis of vertebral counts. 

 Skud (1963) analyzed tag returns, and Carlson 

 (1980) described the ecology of Auke Bay herring. 

 Reid (1971) summarized some biological character- 

 istics of herring taken for the reduction fishery from 

 1929 to 1966. 



Because Pacific herring are economically and 

 ecologically important in southeastern Alaska and 

 there is little information on the growth, produc- 

 tivity, and life history of this species in this region, 

 I undertook a 1-yr study of a population in the Auke 

 Bay vicinity (Auke Bay is about 16 km northwest 

 of Juneau). Goals of the study were to compare 

 growth of Pacific herring in the Auke Bay vicinity 

 with growth of Pacific herring from other locales 

 in the eastern Pacific Ocean and relate annual pro- 

 duction of fat, gonads, and eviscerated weight in the 

 Auke Bay herring to the annual cycle of food supply. 



Pacific herring of the Auke Bay vicinity are one 

 of the innermost and northernmost populations in 



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