Four Decades of Environmental Change and Their Influence upon Native Wildlife and Fish on the Mid-Columbia River, Washington, USA

Abstract

The Hanford Reach of the Columbia River has experienced a great deal of human-imposed environmental change within the past 40 years, as has much of the adjacent land. The major disturbances have been from hydroelectric dams' construction and an intensive expansion of irrigated agriculture. A notable exception to the steady expansion of agriculture and dam-building has been the 1,400 km2 Hanford Site, which was established in 1943. Today, the Hanford Site consists mostly of undeveloped land that still supports native vegetation. It is free from agricultural practices, and has also been essentially free from livestock grazing and the shooting of animal wildlife. This conservative land-use has favoured populations of native wildlife that use the riverine habitats of the Hanford Reach of the Columbia River—e.g. Mule Deer, Canada Goose, and Great Blue Heron, are notable instances.The Hanford Reach supports the only mainstem Chinook Salmon spawning habitat on the Columbia River. This population is maintained by a combination of natural spawning and artificial propagation in concert with a regulated harvest of returning adults. Numbers of mainstem spawning Salmon have increased markedly in the past 10 years, and this has attracted increasing numbers of wintering Bald Eagles to the Hanford Reach.