Waldman et al.: Population bottlenecks and DNA diversity in Morone saxatilis 
619 
bred populations, barely detectable in a non-native, 
outbred, but somewhat genetically constrained popu- 
lation, and pronounced in a non-native, inbred popula- 
tion. Moreover, the inverse association between abun- 
dance and hermaphroditism of the Coos River popula- 
tion suggests (but does not demonstrate) that a de- 
pensatory relationship exists because of these factors. 
That is, demographic influences that continued to re- 
duce genetic diversity of the Coos River population may 
have promoted this pathological reproductive response, 
which then hindered reproduction, further reducing 
abundance and leading to higher levels of inbreeding. 
Furthermore, no strong competing hypotheses 
have emerged to account for hermaphroditism of the 
Coos River striped bass stock. Chemical contamina- 
tion is one conceivable cause. However, the Hudson 
River — the original source of Coos River striped 
bass — is a heavily polluted estuary, yet hermaphro- 
ditism has not been observed in its population. Also, 
the Coos River is home to American shad ( Alosa 
sapidissima), similarly transplanted from the Atlan- 
tic (in 1871 to the Sacramento River; Mansueti and 
Kolb, 1953). In its native east coast rivers, including 
the Hudson River, American shad overlap with 
striped bass both spatially and temporally on their 
spawning runs. Nonetheless, whereas the Coos River 
striped bass population has approached extinction, 
its American shad population is flourishing. 
It is clear that populations of striped bass in Or- 
egon would benefit from broader genetic diversity 
(although there is considerable controversy concern- 
ing maintenance of non-native fish populations; e.g. 
Courtenay, 1995). If perpetuation of the Coos River 
population is desired, consideration should be given 
to the introduction of striped bass to Oregon waters 
from one or more additional Atlantic coast stocks. A 
combination of intention and serendipity resulted in 
the establishment of striped bass in California and 
then Oregon; however, the ultimate effect was to pro- 
mulgate northern, hypothermal, nonmigratory popu- 
lations from individuals originally obtained from a 
midlatitude, mesothermal, migratory population. 
There is some evidence that striped bass from north- 
ern latitudes are better adapted to the ambient en- 
vironmental conditions of those latitudes (Conover, 
1990). We suggest that Atlantic coast striped bass from 
northerly latitudes such as the Canadian Maritimes 
would be more preadapted to Oregon habitats. 
Acknowledgments 
We are grateful to Don Stevens for providing tissue 
samples from California striped bass and to Terry 
Jarmain for Umpqua River samples. 
Literature cited 
Berlinsky, D. L., M. C. Fabrizio, J. F. O’Brien, and 
J. L. Specker. 
1995. Age-at-maturity estimates for Atlantic coast female 
striped bass. Trans. Am. Fish. Soc. 124:207-215. 
Bernatchez, L., J. J. Dodson, and S. Boivin. 
1989. Population bottlenecks: influence on mitochondrial 
DNA diversity and its effect in coregonine stock discrim- 
ination. J. Fish Biol. 35 (suppl. A):233-244. 
Brown, J. R., A. T. Beckenbach, and M. J. Smith. 
1992. Influence of Pleistocene glaciations and human in- 
tervention upon mitochondrial DNA diversity in white stur- 
geon (Acipenser transmontanus ) populations. Can. J. 
Fish. Aquat. Sci. 49:358-367. 
Chapman, R. W. 
1990. Mitochondrial DNA analysis of striped bass popula- 
tions in Chesapeake Bay. Copeia 1990:355-366. 
Conover, D. O. 
1 990. The relationship between capacity for growth and length 
of growing season: evidence for and implications of counter- 
gradient variation. Trans. Am. Fish. Soc. 119:416-430. 
Courtenay, W. R., Jr. 
1995. The case for caution with fish introductions. Am. 
Fish. Soc. Symp. 15:413-424. 
Crow, J. F., and M. Kimura. 
1970. An introduction to population genetics theory. Har- 
per and Row, New York, NY, 591 p. 
Dey, W. P. 
1981. Mortality and growth of young-of-the-year striped 
bass in the Hudson River estuary. Trans. Am. Fish. Soc. 
110:151-157. 
Feinberg, A. P., and B. Vogelstein. 
1983. A technique of radiolabeling DNA restriction endo- 
nuclease fragments to high specific activity. Anal. 
Biochem. 132:6-13. 
Forrester, C. R., A. E. Peden, and R. M. Wilson. 
1972. First records of the striped bass, Morone saxatilis , in 
British Columbia waters. J. Fish. Res. Board Can. 29: 
337-339. 
Gall, G. A. E. 
1987. Inbreeding. In N. Ryman and F. Utter (eds.), Popu- 
lation genetics and fishery management, p. 47-87. Univ. 
Washington Press, Seattle, WA. 
Jimenez, J. A., K. A. Hughes, G. Alaks, L. Graham, and 
R. C. Lacy. 
1994. An experimental study of inbreeding depression in a 
natural habitat. Science (Wash., D.C) 266:271-273. 
Keller, L. F., P. Areese, J. N. M. Smith, W. Hochachka, and 
S. C. Stearns. 
1994. Selection against inbred song sparrows during a natu- 
ral population bottleneck. Nature (Lond.) 372:356-357. 
Kincaid, H. 
1976. Effects of inbreeding on rainbow trout popula- 
tions. Trans. Am. Fish. Soc. 105:273-280. 
Laikre, L., and N. Ryman. 
1991. Inbreeding depression in a captive wolf (Canis lu- 
pus) population. Conserv. Biol. 5:33-40. 
Mansueti, R., and H. Kolb. 
1953. A historical review of the shad fisheries of North 
America. Chesapeake Biological Laboratory Publication 
97, 293 p. 
Moser, M., J. Whipple, J. Sakanari, and C. Reilly. 
1983. Protandrous hermaphroditism in striped bass from 
Coos Bay, Oregon. Trans. Am. Fish. Soc. 112:567-569. 
