Environmental issues with salmon female by 5%, or 104 eggs. If a salmon enters a gillnet, but manages to escape, it often sustains injuries. These injuries can lead to a lower degree of reproductive success. A study aimed at quantifying mortality of Bristol Bay sockeye salmon due to gillnet-related injuries found that 11 – 29% of sockeye sustained fishery-related injuries attributable to gillnets, 51% of those fish were expected to not reproduce. The Columbia River salmon population is now less than 3% of what it was when Lewis and Clark arrived at the river. Salmon canneries established by settlers beginning in 1866 had a
Kokanee salmon of landlocked sockeye has occurred more than once with different kokanee populations, showing genetic differences between populations. Most evidence points to events that land-locked the lake-type sockeye (which spawns in streams and lakes, rather than tributaries like the sea-type sockeye, but is still anadromous and spends most of its adult life out at sea), which evolved into the non-anadromous form. Genetic evidence from kokanee in the Fraser River drainage and Columbia River drainage shows that ancestors of the kokanee came from the lake-type sockeye. The data also suggests that the kokanee may have evolved back into a lake-type anadromous form