News
SpeciesScientists Discover Mysterious New Fish in the Red Sea – and Have Never Seen It AgainOceanEye to eye with Britain's hidden sharks at SharkAdemy - OceanographicRiversIn October, biologists surveying a New York harbor for invasive fish pulled up a bright yellow one. It wasn't an invasive species at allOceanShedd Aquarium Sends Shark Eggs to Bolster Wild PopulationsSpeciesA rare fish has been found in Lake Ontario, North America, whose entire body is golden. It is a nati..OceanThe Great Sea Reef Is Fiji’s Wildest Dive, and a New Frontier for ConservationOceanEckerd College professor contributes to designating Biscayne Bay an Important Shark and Ray AreaSpeciesRio Verde Grande Survey Identifies Fifty-Three Fish Species Facing Flow ReductionsFisheriesAdams River Salmon Run in Thompson-NicolaIndiaHilsa production dropped 26% in five years, fisheries minister tells parliamentSpeciesScientists Discover Mysterious New Fish in the Red Sea – and Have Never Seen It AgainOceanEye to eye with Britain's hidden sharks at SharkAdemy - OceanographicRiversIn October, biologists surveying a New York harbor for invasive fish pulled up a bright yellow one. It wasn't an invasive species at allOceanShedd Aquarium Sends Shark Eggs to Bolster Wild PopulationsSpeciesA rare fish has been found in Lake Ontario, North America, whose entire body is golden. It is a nati..OceanThe Great Sea Reef Is Fiji’s Wildest Dive, and a New Frontier for ConservationOceanEckerd College professor contributes to designating Biscayne Bay an Important Shark and Ray AreaSpeciesRio Verde Grande Survey Identifies Fifty-Three Fish Species Facing Flow ReductionsFisheriesAdams River Salmon Run in Thompson-NicolaIndiaHilsa production dropped 26% in five years, fisheries minister tells parliament
EveryFish

River or lake, United States

The Columbia River at Bonneville

The first big dam on the Columbia, where salmon climb fish ladders past windows that count every fish.

Bonneville Dam, completed in 1938, was the first of the large federal dams on the Columbia River, about 65 km east of Portland. It was built with fish ladders, and visitors can watch salmon, steelhead and lampreys swim past underwater windows where counters record every fish. The Columbia once had some of the largest salmon runs on Earth, and its dams changed them more than any other river's.

Ladders and counts

Adult salmon climb the ladders in stages, resting in pools between low steps. The daily counts at Bonneville are published and used to manage fishing seasons on the river. Young salmon heading downstream face a harder task: passing through turbines or over spillways at dam after dam. Barging and trucking juveniles past the dams, spilling water and fish-friendly turbines are used to improve their survival.

Tribes, treaties and sturgeon

Columbia River tribes have fished for salmon for thousands of years, and their treaty fishing rights are protected by law and by court rulings. Celilo Falls, a great fishing place, was drowned by The Dalles Dam in 1957. The river also holds white sturgeon, North America's largest freshwater fish, and Pacific lampreys, whose decline the tribes have worked to reverse. Proposals to remove dams on the Snake River, a tributary, remain hotly debated.

Fish of The Columbia River at Bonneville

Sockeye salmonBound for lakes far upstreamPacific lampreyAn ancient fish sacred to the river's tribes

Still to be written: Chinook salmon, Coho salmon, Rainbow trout, White sturgeon.

Photo credits on this page

The small pictures above come from Wikimedia Commons under free licences. Some are cropped to fit.

The weekly digest

Every Monday: the fish of the day, new pages on EveryFish, and the conferences and anniversaries of the week ahead.