Whether it's sockeye, king, or coho, salmon is one well-traveled fish.

Wild salmon swim an average of 150 miles from the ocean to fresh water rivers.

Some go much farther. One record-holding chinook salmon made it 3,500 miles.

Generally, Atlantic salmon are farmed, while those from the Pacific are wild.
Farm-raised salmon tend to have higher levels of contaminants than wild salmon, but scientists aren't sure whether these levels pose a health risk.

Both types of salmon are relatively low in mercury.

Both are also a good source of omega-3 fats, which may lower your risk of heart disease.

And like other fish, salmon is a good source of protein.

Some farmed salmon get their color from dye added to their feed. But wild salmon get their color from the krill they eat.

To gain one pound, they need to eat 10 pounds of krill and other fish.

Adult salmon typically weigh 3 to 20 pounds depending on the species. But some chinook salmon can grow to more than 125 pounds.

After living in fresh water rivers, salmon travel to the ocean, where they stay for 1 to 6 years, and then go home to spawn in the stream where they were born.

Scientists aren't sure how they manage to find their way back. But it's an amazing fish tale that's actually true.