Columbia River Fish and Aquatic Ecology
Historically, the fish community in the Columbia River and its tributaries was characterized by fishes uniquely adapted to this high gradient, cold-water river system. Pacific salmon used the inland habitats of the Columbia River Basin to spawn and rear, and the productive coastal areas of the Pacific Ocean to feed as juveniles and adults. Resident fishes, such as white sturgeon, migrated large distances to take advantage of seasonally abundant food sources (e.g., salmon, smelt) and spawned in the mainstem, while other native resident fishes fed on macroinvertebrates in the mainstem Columbia River and spawned in the tributaries. Along with Pacific salmon, many other species of fish occur within the Columbia River and throughout the Basin, many of which have cultural, commercial, or sport importance. Some of the native species include white sturgeon (Acipenser transmontanus), rainbow and redband trout (Oncorhynchus mykiss), stocks, whitefish, various species of suckers, sculpins, minnows, and many other species.
During the last 200 years, changes in the Basin have caused many fish populations to decline, and aquatic communities have shifted significantly. Damming of rivers, logging, mining, and urban development have occurred throughout the region. Numerous exotic species have been introduced to the Basin during the last 150 years, causing a considerable change in the aquatic community. Climate change and climate regime shifts, along with human impacts, have altered the flow patterns, water quality, and water temperature of the rivers, lakes, and streams.
The economic, cultural, and sport importance of the fish and aquatic communities, along with the drastic changes that have occurred, have made management of natural aquatic resources a high priority in the region. This Project aims to provide a sound scientific understanding of some of these problems, and to offer good data upon which managers can make sound decisions.