FISHERY BULLETIN: VOL. 86, NO. 4 



which the species is particularly well adapted. Along 

 the west coast of North America, these alternations 

 are best developed off northern and central Califor- 

 nia (Bakun 1973; Bakun et al. 1974; Mason and 

 Bakun 1985). And not only is S. mystinus most 

 numerous off this same section of the coast, it is 

 perhaps the dominant fish in the nearshore habitat 

 there (Hallacher and Roberts 1985; Bodkin 1984; our 

 observations). Although the species is reported from 

 northern Baja California, Mexico, to the Bering Sea 

 (Miller and Lea 1972), its numbers are sharply 

 reduced northward from northern California (Alver- 

 son et al. 1964; Frey 1971; Hart 1973) and south- 

 ward from central California (Hubbs 1948; Lim- 

 baugh 1955; Quast 1968). Although undoubtedly 

 other factors are involved, we suggest that occur- 

 rences of S. mystinus in these northern and south- 

 ern regions are limited by less favorable feeding 

 conditions. 



ACKNOWLEDGMENTS 



Daniel Howard assisted in the field work and 

 performed various aspects of data processing. 

 Michael Bowers prepared the histological sections 

 represented by Figure 7, and Louis Rouleau, NOAA 

 weather observer at Mendocino, provided wind data 

 used in Figures 4 and 9. For constructive criticism 

 of the manuscript we thank Andrew Bakun, John 

 Hunter, William Pearcy, and Richard Rosenblatt. 

 Rahel Fischer typed the manuscript. 



LITERATURE CITED 



Abbott, I. A., and C. J. Hollenberg. 



1976. Marine algae of California. Stanford Univ. Press, 

 Stanford, 827 p. 

 Alverson, D. L., a. T. Pruter, and L. L. Ronholt. 



1964. A study of demersal fishes and fisheries of the north- 

 eastern Pacific Ocean. H. R. MacMillan Lectures in Fish- 

 eries. Inst. Fish. Univ. British Columbia, 190 p. 

 Bakun, A. 



1973. Coastal upwelling indices, west coast of North America, 

 1946-71. U.S. Dep. Commer., NOAA Tech. Rep. NMFS 

 SSRF-671, 103 p. 



1975. Daily and weekly upwelling indices, west coast of North 

 America, 1967-73. U.S. Dep. Commer., NOAA Tech. Rep. 

 NMFS SSRF-693, 114 p. 

 Bakun, A., D. R. McLain, and F. V. Mayo. 



1974. The mean annual cycle of coastal upwelling off western 

 North America as observed from surface measurements. 

 Fish. Bull., U.S., 72:843-844. 



Bakun, A., and R. H. Parrish. 



1980. Environmental inputs to fishery population models for 

 eastern boundary current regions. In G. A. Sharp (editor). 

 Workshop on the effects of environmental variation on lar- 

 val pelagic fishes, p. 67-104. Workshop Rep. 28, Intergov. 



Ocean. Comm., UNESCO. Paris. 

 Barber, R. T., and R. C. Smith. 



1981. Coastal upwelling systems. In A. R. Longhurst 

 (editor). Analysis of marine ecosystems, p. 31-68. Acad. 

 Press, N.Y. 



Berrill, N. J. 



1961. Salpa. Sci. Am. 204:150-160. 

 BlERl, R. 



1959. Dimorphism and size distribution in Velella and 

 Physalia. Nature 184:1333. 

 BoJE, R., and M. Tomczak (editors). 



1978. Upwelling systems. Springer-Verlag, N.Y., 303 p. 

 Blackburn, M. 



1975. Thaliacea of the California Current region: rela- 

 tions to temperature, chlorophyll, currents and upwelling. 

 CALCOFI Rep. 20:183-214. 



Bodkin, J. L. 



1986. Fish assemblages in Macrocystis and Nereocystis kelp 

 forests off central California. Fish. Bull., U.S. 84:799-808. 



Bolin, R. L., and D. p. Abbott. 



1962. Studies on the marine climate and phytoplankton of the 

 central coastal area of California, 1954-1960. CALCOFI 

 Rep. 9:23-45. 



Chelton, D. B., p. a. Bernal, and J. A. McGowan. 



1982. Large scale interannual physical and biological inter- 

 actions in the California Current. J. Mar. Res. 40:1095- 

 1125. 



Ekman, V. W. 



1905. On the influence of the earth's rotation on ocean cur- 

 rents. Ark. Mat. Astron. Fys. 2,11:1-52. 

 Frey, H. W. (editor). 



1971. California's living marine resources and their utiliza- 

 tion. Calif. Dep. Fish Game, 148 p. 

 Gaines, S. D., and J. Roughgarden. 



1987. Fish in offshore kelp forests affect recruitment to inter- 

 tidal barnacle populations. Science 235:479-481. 



Gotshall, D. W., J. G. Smith, and A. Holbert. 



1965. Food of the blue rockfishSe6astodes7nt/s<twws. Calif. 

 Dep. Fish Game 51:147-162. 

 Gross, M. G. 



1977. Oceanography. 2d ed. Prentice-Hall, N.J. 497 p. 

 Hallacher, L. E., and D. A. Roberts. 



1985. Differential utilization of space and food by the inshore 

 rockfishes (Scorpaenidae: Sebastes) of Carmel Bay. Environ. 

 Biol. Fish. 12:91-110. 

 Hart, J. L. 



1973. Pacific fishes of Canada. Fish. Res. Board Can., 

 Ottawa, 740 p. 

 Heron, A. C. 



1972a. Population ecology of a colonizing species: the pelagic 

 tunicate Thalia democratica. I Individual growth and 

 generation time. Oecologia (Berl.) 10:269-293. 

 1972b. Population ecology of a colonizing species: the pelagic 

 tunicate Thalia democratica. II population growth 

 rate. Oecologia (Berl.) 10:294-312. 

 HoBSON, E. S., AND J. R. Chess. 



1976. Trophic interactions among fishes and zooplankters 

 near shore at Santa Catalina Island, California. Fish. Bull., 

 U.S., 74:567-598. 



Hubbard, L. T., and W. G. Pearcy. 



1971. Geographic distribution and relative abundance of 

 Salpidae off the Oregon Coast. J. Fish. Res. Board Can. 

 28:1831-1836. 

 Hubbs, C. L. 



1948. Changes in the fish fauna of western North America 



742 



