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
Why do salmon eggs come in different colors? Why do salmon eggs come in different colors?
Salmon eggs (roe) range in color from pale yellowish-orange to dark reddish-orange. The color varies both by species and within species and is determined by water temperature, sediment composition, age, and other factors. The eggs vary in size from the tiny sockeye roe (average ¼ inch or 5.6 mm) to the large chum roe (average almost ½ inch or 8.3 mm). Also, if a salmon egg does not get fertilized...
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...
Where can I find fish consumption advisories for my state? Where can I find fish consumption advisories for my state?
Most states have set fish (and wildlife) consumption advisories and recommended consumption levels. The state agency responsible for these limits varies. Examples of consumption advisory information can be found at the Environmental Protection Agency's Fish and Shellfish Advisories and Safe Eating Guidelines website.
Related
Why do salmon eggs come in different colors? Why do salmon eggs come in different colors?
Salmon eggs (roe) range in color from pale yellowish-orange to dark reddish-orange. The color varies both by species and within species and is determined by water temperature, sediment composition, age, and other factors. The eggs vary in size from the tiny sockeye roe (average ¼ inch or 5.6 mm) to the large chum roe (average almost ½ inch or 8.3 mm). Also, if a salmon egg does not get fertilized...
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...
Where can I find fish consumption advisories for my state? Where can I find fish consumption advisories for my state?
Most states have set fish (and wildlife) consumption advisories and recommended consumption levels. The state agency responsible for these limits varies. Examples of consumption advisory information can be found at the Environmental Protection Agency's Fish and Shellfish Advisories and Safe Eating Guidelines website.