will be caught in fishermen's nets. Those that evade the nets may have to swim through polluted waters near cities. Many must make their way over power dams on fish ladders. In the tributary streams, waterfalls and rapids are steep and swift enough to eliminate all but the strongest. Otters, eagles, and bears stalk the salmon in shallow riffles. Once on the spawning grounds, the fish battle each other: females against females for places to nest, males against males for available females. Most adult Pacific salmon species feed on aquatic insects and small fish. They require pure, well-oxygenated cold water and are one of the first species to suffer when water quality is degraded. Many are seriously threatened by habitat destruction, hydroelectric dams on migratory rivers, over-harvest of rare stocks, and competition with hatchery fish. Organism 10: SteelheadScientific Name: Oncorhynchus mykissSteelheads are slender with a blue-green color and regularly spaced spots. The black spots also cover both lobes of the tail. The black coloration fades over the lateral line to a silver white coloration blending more to white on the stomach. Steelhead and rainbow develop a distinct pink to red strip-like coloration that blends along the side, both above and below the lateral line. The distinct and beautiful coloration of steelhead during the freshwater spawning period is apparently important in regard to the mating and reproductive process. The silvery sheen and streamlined shape of ocean-bright steelhead is essential to survival in the ocean environment. Steelhead habitat requirements change as they go through different life phases. Adult steelheads need to have access to their natal streams for spawning. The best pools for habitat are those with cover in the form of large woody debris, undercut banks, root masses, and large boulders. Cool, clean water is essential for the survival of steelhead during all portions of their life cycle. In Nor...
