Migration and stock-recruitment of naturally produced Pacific salmonids (Oncorhynchus) in three Lake Ontario tributaries

An understanding of natural reproduction and recruitment in Great Lakes tributaries requires estimates of adult escapement and abundance of migratory juveniles. Three tributaries of Lake Ontario were investigated from 1988 to 1992 using modified auger traps. Migrations of naturally produced chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), steelhead (O. mykiss), and other fish species were monitored annually from April to August.;Auger traps proved capable of capturing smolts at most flow regimes encountered and worked best at discharges ranging from 1-10 m;Annual migration timing of Pacific salmon smolts varied yearly in the study streams. Age-1 coho and age-1 and 2 steelhead left the streams over a protracted period. Chinook migrations were more periodic, occurring from mid-June to early-July annually. During 1989, 30-79% of the total chinook smolt catch occurred over a 3-night period following a rainstorm.;The yield of age-0 chinook smolts (determined from available rearing area within the drainage) ranged from 16 ;A density-independent stock-recruitment relationship was described for a population of chinook salmon in an eastern tributary of Lake Ontario. The annual number of migrating smolts was highly correlated with adult escapement (r...