North American Journal of Fisheries Management

I estimated fecundities for two stocks of Chinook salmon Oncorhynchus tshawytscha from the same drainage in southwestern Alaska using a length based linear regression. Female Chinook salmon from the main stem of the Naknek River had a mean fecundity of 9,852 eggs per fish. Big Creek, a tributary stream, had a mean fecundity of 9,060 eggs per female. The observed difference in fecundities was found to be significant (p < 0.001). I was able to attribute this difference primarily to a difference between the size class structures of the two stocks. I also eliminated other alternative hypothesis as to why these stocks had different fecundities. I then speculated that there are selective pressures selecting for smaller spawners in Big Creek mainly due to shallow water depth. Further research is needed before this hypothesis can be validated or management recommendations can be made.