Brennan and Emily collect and transfer salmon plasma to assess for PFAS
Why are there so few salmon left?
There are many reasons for the decline in salmon populations. Logging an area around a stream reduces the shade and nutrients available to the stream and increases the amount of silt or dirt in the water, which can choke out developing eggs. Dams cause fish to die from the shock of going through the turbines and from predators that eat the disoriented fish as they emerge from the dam. Overfishing is another source of death that can contribute to the decline of salmon. The weather affects the amount of food that is available to salmon in the ocean. Pollution and disease have also contributed to population declines.
Learn more: Western Fisheries Research Center - Questions and Answers about Salmon
Related
How long do salmon usually live? How long do salmon usually live?
Most salmon species live 2 to 7 years (4 to 5 average). Steelhead trout can live up to about 11 years. Learn more: Western Fisheries Research Center - Questions and Answers about Salmon
How many species of salmon are there and how large can they get? How many species of salmon are there and how large can they get?
There are seven species of Pacific salmon. Five of them occur in North American waters: chinook, coho, chum, sockeye, and pink. Masu and amago salmon occur only in Asia. There is one species of Atlantic salmon. Chinook/King salmon are the largest salmon and get up to 58 inches (1.5 meters) long and 126 pounds (57.2 kg). Pink salmon are the smallest at up to 30 inches (0.8 meters) long and 12...
Why do salmon change color and die after they spawn? Why do salmon change color and die after they spawn?
Salmon change color to attract a spawning mate. Pacific salmon use all their energy for returning to their home stream, for making eggs, and digging the nest. Most of them stop eating when they return to freshwater and have no energy left for a return trip to the ocean after spawning. After they die, other animals eat them (but people don't) or they decompose, adding nutrients to the stream...
How do salmon know where their home is when they return from the ocean? How do salmon know where their home is when they return from the ocean?
Salmon come back to the stream where they were 'born' because they 'know' it is a good place to spawn; they won't waste time looking for a stream with good habitat and other salmon. Scientists believe that salmon navigate by using the earth’s magnetic field like a compass. When they find the river they came from, they start using smell to find their way back to their home stream. They build their...
Interns collect salmon blood
Brennan and Emily collect and transfer salmon plasma to assess for PFAS
5 Ways Climate Affects Salmon
Five ways climate change is affecting Salmon.
Graphic by Courtenay Duzet, USGS.
Five ways climate change is affecting Salmon.
Graphic by Courtenay Duzet, USGS.
Salmon migrating upstream Underwood Creek, Wisconsin, from Lake Michigan to spawn
Salmon migrating upstream Underwood Creek, Wisconsin, from Lake Michigan to spawnTime lapse video of salmon migrating upstream from Lake Michigan to spawn, taken on October 22, 2022, at Underwood Creek at Wauwatosa, Wisconsin (https://waterdata.usgs.gov/monitoring-location/04087088/).
Salmon migrating upstream Underwood Creek, Wisconsin, from Lake Michigan to spawn
Salmon migrating upstream Underwood Creek, Wisconsin, from Lake Michigan to spawnTime lapse video of salmon migrating upstream from Lake Michigan to spawn, taken on October 22, 2022, at Underwood Creek at Wauwatosa, Wisconsin (https://waterdata.usgs.gov/monitoring-location/04087088/).
PubTalk-10/2021: Zombie Salmon and Ghost Moose
Zombie Salmon and Ghost Moose - The Spooky Implications of Climate Change
By Laura Thompson & Abigail Lynch, USGS National Climate Adaptation Science Center
Zombie Salmon and Ghost Moose - The Spooky Implications of Climate Change
By Laura Thompson & Abigail Lynch, USGS National Climate Adaptation Science Center
Steelhead Salmon eggs in beaker
Orange Steelhead Salmon eggs
Orange Steelhead Salmon eggs
Image of Sockeye salmon
Image of sockeye salmon. Photo provided by Milton Love, Marine Science Institute, University of California, Santa Barbara.
Image of sockeye salmon. Photo provided by Milton Love, Marine Science Institute, University of California, Santa Barbara.
Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016
Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016
Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016
Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016
PubTalk 2/2015 — Undamming Washington's Elwha River
PubTalk 2/2015 — Undamming Washington's Elwha Riverby Amy East USGS Research Geologist
- Hear about river response to the largest dam removal in history.
- Causing disturbance as a means of restoration: how well does it work?
- Will legendary salmon runs return?
PubTalk 2/2015 — Undamming Washington's Elwha River
PubTalk 2/2015 — Undamming Washington's Elwha Riverby Amy East USGS Research Geologist
- Hear about river response to the largest dam removal in history.
- Causing disturbance as a means of restoration: how well does it work?
- Will legendary salmon runs return?
Recording data for female spring Chinook salmon
Dr. Wendy Olson, USFWS biologist (orange rain pants) records data for female spring Chinook salmon being spawned at the hatchery. Among the data recorded are fin clips designating treatment groups for the research project (erythromycin treatment, tulathromycin treatment, or no treatment).
Dr. Wendy Olson, USFWS biologist (orange rain pants) records data for female spring Chinook salmon being spawned at the hatchery. Among the data recorded are fin clips designating treatment groups for the research project (erythromycin treatment, tulathromycin treatment, or no treatment).
Atlantic Salmon (Salmo salar)
Zoe Zyollewski handles an adult Atlantic salmon caught in the Connecticut River.
Zoe Zyollewski handles an adult Atlantic salmon caught in the Connecticut River.
Related
How long do salmon usually live? How long do salmon usually live?
Most salmon species live 2 to 7 years (4 to 5 average). Steelhead trout can live up to about 11 years. Learn more: Western Fisheries Research Center - Questions and Answers about Salmon
How many species of salmon are there and how large can they get? How many species of salmon are there and how large can they get?
There are seven species of Pacific salmon. Five of them occur in North American waters: chinook, coho, chum, sockeye, and pink. Masu and amago salmon occur only in Asia. There is one species of Atlantic salmon. Chinook/King salmon are the largest salmon and get up to 58 inches (1.5 meters) long and 126 pounds (57.2 kg). Pink salmon are the smallest at up to 30 inches (0.8 meters) long and 12...
Why do salmon change color and die after they spawn? Why do salmon change color and die after they spawn?
Salmon change color to attract a spawning mate. Pacific salmon use all their energy for returning to their home stream, for making eggs, and digging the nest. Most of them stop eating when they return to freshwater and have no energy left for a return trip to the ocean after spawning. After they die, other animals eat them (but people don't) or they decompose, adding nutrients to the stream...
How do salmon know where their home is when they return from the ocean? How do salmon know where their home is when they return from the ocean?
Salmon come back to the stream where they were 'born' because they 'know' it is a good place to spawn; they won't waste time looking for a stream with good habitat and other salmon. Scientists believe that salmon navigate by using the earth’s magnetic field like a compass. When they find the river they came from, they start using smell to find their way back to their home stream. They build their...
Interns collect salmon blood
Brennan and Emily collect and transfer salmon plasma to assess for PFAS
Brennan and Emily collect and transfer salmon plasma to assess for PFAS
5 Ways Climate Affects Salmon
Five ways climate change is affecting Salmon.
Graphic by Courtenay Duzet, USGS.
Five ways climate change is affecting Salmon.
Graphic by Courtenay Duzet, USGS.
Salmon migrating upstream Underwood Creek, Wisconsin, from Lake Michigan to spawn
Salmon migrating upstream Underwood Creek, Wisconsin, from Lake Michigan to spawnTime lapse video of salmon migrating upstream from Lake Michigan to spawn, taken on October 22, 2022, at Underwood Creek at Wauwatosa, Wisconsin (https://waterdata.usgs.gov/monitoring-location/04087088/).
Salmon migrating upstream Underwood Creek, Wisconsin, from Lake Michigan to spawn
Salmon migrating upstream Underwood Creek, Wisconsin, from Lake Michigan to spawnTime lapse video of salmon migrating upstream from Lake Michigan to spawn, taken on October 22, 2022, at Underwood Creek at Wauwatosa, Wisconsin (https://waterdata.usgs.gov/monitoring-location/04087088/).
PubTalk-10/2021: Zombie Salmon and Ghost Moose
Zombie Salmon and Ghost Moose - The Spooky Implications of Climate Change
By Laura Thompson & Abigail Lynch, USGS National Climate Adaptation Science Center
Zombie Salmon and Ghost Moose - The Spooky Implications of Climate Change
By Laura Thompson & Abigail Lynch, USGS National Climate Adaptation Science Center
Steelhead Salmon eggs in beaker
Orange Steelhead Salmon eggs
Orange Steelhead Salmon eggs
Image of Sockeye salmon
Image of sockeye salmon. Photo provided by Milton Love, Marine Science Institute, University of California, Santa Barbara.
Image of sockeye salmon. Photo provided by Milton Love, Marine Science Institute, University of California, Santa Barbara.
Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016
Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016
Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016
Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016Steelhead Salmon Captured In Lake Ontario By Staff from From The Tunison Laboratory Of Aquatic Science In May 2016
PubTalk 2/2015 — Undamming Washington's Elwha River
PubTalk 2/2015 — Undamming Washington's Elwha Riverby Amy East USGS Research Geologist
- Hear about river response to the largest dam removal in history.
- Causing disturbance as a means of restoration: how well does it work?
- Will legendary salmon runs return?
PubTalk 2/2015 — Undamming Washington's Elwha River
PubTalk 2/2015 — Undamming Washington's Elwha Riverby Amy East USGS Research Geologist
- Hear about river response to the largest dam removal in history.
- Causing disturbance as a means of restoration: how well does it work?
- Will legendary salmon runs return?
Recording data for female spring Chinook salmon
Dr. Wendy Olson, USFWS biologist (orange rain pants) records data for female spring Chinook salmon being spawned at the hatchery. Among the data recorded are fin clips designating treatment groups for the research project (erythromycin treatment, tulathromycin treatment, or no treatment).
Dr. Wendy Olson, USFWS biologist (orange rain pants) records data for female spring Chinook salmon being spawned at the hatchery. Among the data recorded are fin clips designating treatment groups for the research project (erythromycin treatment, tulathromycin treatment, or no treatment).
Atlantic Salmon (Salmo salar)
Zoe Zyollewski handles an adult Atlantic salmon caught in the Connecticut River.
Zoe Zyollewski handles an adult Atlantic salmon caught in the Connecticut River.
Updated Date: August 7, 2026