The coho salmon populations have drastically decreased over the years. These figures represent the decreasing numbers of the coho salmon populations. The Columbia River is a major route of the salmon and the population decrease is seen in the local river drainage. The majority of these decreases are due to commercial fishing and passing through several of the dams located along the migration routes. Management efforts in the surrounding rivers such as the Snake and Columbia focus on certain limitations.
Biologists look at production of the salmon in variable natural environments.
They also may look at the way populations change over time, or the number of spawners for future production. Biologists collect data from these areas and try to manage the populations to benefit the populations and keep them healthy. The management of the coho salmon needs to meet agreements between the tribes and the biologists. In order to effectively manage the salmon populations both of these groups must agree with each other in a way that benefits the salmon. The salmon market also depends on management efforts and relies on supply and demand.