The Indian River Ecosystem Anadromous fish
Anadromous fish use the river as habitat for migration, spawning, incubation of eggs, and rearing of young. Anadromous fish are those that live in the sea as adults but return to their natal freshwater streams to spawn. Four species of Pacific salmon (Pink, Chum, Coho, and King), two species of trout (cutthroat and rainbow, also known as Steelhead), and one char (Dolly Varden) spawn in the Indian River. Pacific Salmon die after spawning whereas trout and char may return to the river several times to spawn. (Learn more about the salmon life cycle.)
Pink and chum salmon enter the intertidal and lower segments of the Indian River to spawn from mid-July through September. The fry emerge and migrate to the ocean from late-February through mid-May. Numbers of pink salmon surpass other salmon species in the stream with an estimated 1.3 million fish returning in 2003.
Coho salmon, chinook salmon, and steelhead trout migrate upstream but have not been observed spawning in the park. The primary rearing and spawning habitat for coho salmon, chinook salmon, and steelhead trout is above the Sheldon Jackson College diversion dam. A fish pass along the dam allows upstream access for these species under certain flow conditions. Coho salmon return to the Indian River from late September through November and spawn in upper portion of river. Some spawning chinook but no existing wild populations are thought to be strays from area hatcheries.
Anadromous Dolly Varden enter the river in August, migrating upriver through the park to spawn farther upstream. The fry emerge from the gravels in the spring and disperse throughout the river.
Salmon returning to natal streams to spawn transport nutrients and energy from the ocean to the freshwater environment. These are vital to the overall health of the coastal ecosystems and affect stream productivity. (Learn more about stream ecology.)