Estimating the Embryonic Survival of Brown Trout in the Salmon River, New York

The Salmon River receives spawning runs of brown trout (Salmo trutta) and three species of Pacific salmon (Oncorhynchus spp.) from Lake Ontario.  All three species of Pacific Salmon are documented to have high reproductive success.  However, recent studies indicate that brown trout may not be reproducing successfully.  The goal of this study is to determine the survival rate of brown trout embryos from fertilization until emergence.  The survival rate will be determined by excavating a 0.25 m² section of a set of redds to determine the proportion of viable embryos.  We also placed Chinook salmon (Oncorhynchus tshawytscha) and brown trout embryos from hatchery stock, inside perforated plastic tubes and inserted them into natural redds of both species.  Preliminary results indicate that brown trout embryos have high survival rates during the early stages of development in this system.  Additionally, Chinook salmon and brown trout embryos from hatchery stock have high survival rates when placed in natural redds of both species.  This suggests that both species are building redds that are conducive to embryonic survival in the Salmon River system.