Water temperatures above 68 degrees Fahrenheit can be lethal to salmon and trout. High stream temperatures may allow carp, suckers, sunfish, and other temperature tolerant species to dominate at the expense of salmon and trout. Riparian trees and branches regularly fall into streams. This large woody debris is extremely important to salmon and trout survival. It provides cover, protection from predators, resting areas, and important habitat for aquatic insects and small fish that salmon and trout eat.
Debris dams help form pool areas that are essential to fish habitat.
Portland recognizes the importance of streamed trees and shrubs and the City has environmental zoning regulations designed to protect riparian vegetation. Development standards limit the number of trees that can be removed from sensitive areas, require replacement of trees illegally removed, and require new development to be set back from stream banks. Portland is reviewing these regulations and standards with an eye toward strengthening protection of salmon and trout. What Developers Can Do Portland can grow, and development can occur, without destroying salmon and trout habitat in the process. Development that minimizes impacts on fish habitat will help the recovery process.