Overripening as the cause of low survival to hatch in Lake Erie coho salmon (Oncorhynchus kisutch) embryos

We investigated the cause of the low survival to hatch of embryos of coho salmon (Oncorhynchus kisutch) from the Fairview, Pennsylvania, stock in Lake Erie. In 1988, survival to hatch of this stock was only 42%, whereas another Great Lakes coho salmon stock of similar genetic origin had an 84% survival to hatch. Laboratory cross-fertilization studies between the Fairview stock and a reference Lake Erie stock from Simcoe, Ontario, showed that …