Acknowledgments 



We thank the Fishery Agency of Japan for al- 

 lowing our participation in 1978 and 1979 cruises. 

 The cooperation and hospitality extended to us 

 was admirable. R. L. Brownell, Jr., National Fish 

 and Wildlife Laboratory, U.S. Fish and Wildlife 

 Service, arranged the participation of Ainley and 

 DeGange, and Ainley 's efforts were funded by that 

 office. Help in the laboratory was contributed by 

 A. E. Good. The comments by R. L. Brownell, W B. 

 King, and two anonymous reviewers greatly im- 

 proved the manuscript. 



Literature Cited 



Ainley, D. G. 



1977. Feeding methods in seabirds: a comparison of polar 

 and tropical nesting communities in the eastern Pacific 

 Ocean. In G. A. Llano (editor). Adaptations within 

 Antarctic ecosystems, p. 669-685. Gulf Publ., Houston. 



Christensen, O., and W. H. Lear. 



1976. Bycatches in salmon drift-nets at West Greenland in 



1972. Medd. Grpnl. 5(205):l-29. 

 FAVORITE, E, A. J. DODIMEAD, AND K. NASU. 



1976. Oceanography of the subarctic Pacific region, 



1969-71. Int. North Pac. Fish. Comm., Bull. 33:1-187. 



KING, W. B., R. G. B. Brown, and G. A. Sanger. 



1979. Mortality to marine birds through commercial fish- 

 ing. In J. C. Bartonek and D. N. Nettleship (editors). 

 Conservation of marine birds of northern North America, 

 p. 195-200. U.S. Fish Wildl. Serv., Wildl. Res. Rep. 11. 



Sanger, G. A. 



1976. Update on seabird mortality from salmon driftnets. 

 Pac. Seabird Group Bull. 3(2):30-32. 

 Sano, O. 



1978. Seabirds entangled in salmon driftnets. Enyo 

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SOKAL, R. R., AND F J. ROHLF. 



1969. Biometry; The principles and practice of statistics in 

 biological research. W. H. Freeman, San Franc, 776 p. 

 TULL, C. E., R GERMAIN, AND A. W. MAY. 



1972 Mortality of Thick-billed Murres in the West Green- 

 land Salmon Fishery Nature (Lond.) 237:42-44. 



Point Reyes Bird Observatory 

 Stinson Beach, CA 94970 



David G. ainley 



Anthony r. deGange 



Office of Biological Services 

 U.S. Fish and Wildlife Service 

 Portland, OR 97232 



LINDA L. Jones 

 Richard J. Beach 



Northwest and Alaska Fisheries Center National Marine 

 Mammal Laboratory, National Marine Fisheries Service, NOAA 

 7600 Sand Point Wav, Seattle, WA 98115 



HISTOCHEMICAL INDICATIONS OF 



LIVER GLYCOGEN IN SAMPLES OF 



EMACIATED AND ROBUST LARVAE OF THE 



NORTHERN ANCHOVY, ENGRAULIS MORDAX 



On the basis of histological criteria (O'Connell 

 1976), 8% of northern anchovy, Engraulis mor- 

 dax, larvae from special net tows taken in the 

 Southern California Bight in March 1977 were 

 found to be in starving condition ( O'Connell 1980). 

 Almost three-quarters of the larvae that showed 

 signs of starvation were concentrated in 4 of the 64 

 net tow samples. The present report compares the 

 amount of glycogen in livers of additional larvae 

 drawn from these four samples to that in the livers 

 of larvae from samples taken in the same area, 

 which contained robust larvae almost exclusively. 



Glycogen, which is stored in the liver and 

 transformed to glucose as needed to maintain an 

 adequate blood sugar level, is the most imme- 

 diately available of the three energy sources, 

 glycogen, lipid, and protein (Love 1974). It is 

 known to virtually disappear from the livers of 

 many teleosts after only a few days of starvation 

 (Black et al. 1966; Inui and Ohshima 1966; Bella- 

 my 1968), but fish generally live long beyond the 

 depletion of liver glycogen, maintaining the blood 

 sugar level by gluconeogenesis (Love 1974; Cowey 

 and Sargent 1979). However, there are also tele- 

 osts in which liver glycogen does not decline 

 sharply at the onset of starvation, although gluco- 

 neogenesis does increase (Cowey and Sargent 

 1979). Thus abundance of liver glycogen cannot be 

 considered a dependable indicator of starvation in 

 teleosts, at least not for adult stages. 



Postyolk-sac larval stages, which first exhibit 

 stained liver glycogen about the time yolk is 

 depleted, are more likely to show a drop in liver 

 glycogen at onset of starvation. First feeding 

 northern anchovy larvae die after only a few days 

 of starvation (O'Connell 1976), indicating that 

 reserves are limited. Lipid reserves, for example, 

 are known to be negligible in early postyolk-sac 

 herring and plaice larvae (Ehrlich 1974), and even 

 at the relatively large size of 35 mm SL northern 

 anchovy larvae survive starvation conditions for 

 only 2 wk, on the average, during which time lipid 

 reserves are severely depleted (Hunter 1976). 

 Presumably liver glycogen declines sharply before 

 lipid reserves are depleted in these early stages. 



The estimates of glycogen reserves in the works 

 cited above, and in many others, are derived from 

 weight-based biochemical determinations, which 



806 



fishery BULLETIN; VOL. 79, NO. 4, 1981 



