In the Pacific Northwest, salmon were abundant in the rivers. Today it is extinct in 40 percent of these rivers. California, Washington, Oregon and Idaho have experienced the biggest impact of the declining population. In the United Kingdom, the population has been shrinking resulting in strict fishing quotas.
There are seven species of salmon, six Pacific and one Atlantic. The Pacific species are Cherry, Chinook, Chum, Coho, Pink and Sockeye. These species are born in fresh water, migrate to the ocean and return to fresh water to breed. Cousin to this fish is the steelhead or rainbow trout which breeds and resides in fresh water.
It is a popular food fish and source of omega-3. It is also the main source of food for many predators. The decomposed carcasses provide nutrients and fertilizers for trees. Global warming, El Nino, its complicated life cycle and overfishing have been attributed to its declining population.
Governments have been lax in controlling the amount of fish that can be caught. Only Alaska has established a program to sustain the salmon population. Overfishing led to depletion and the rise of fish hatcheries. The hatcheries would artificially raise the fish and release it into the wild. Inbreeding, parasites and disease increased causing the wild population to decrease.
Logging, agricultural practices, trash dumping and oil spills have created poorer water quality. This has impacted the delicate life cycle of the fish. Establishments of dams have caused changes to water flow. water temperature and not allowing the salmon to reach its birthing grounds. Warmer water temperatures have resulted in it migrating north delaying its return to its spawning grounds.
The salmon population can survive and eventually increase with proper environmental controls. Each element, overfishing, hatcheries, poorer water quality and dam building, must be be analyzed and managed to provide the fish with the right environment.