No obvious connection unites trees and salmon, but look beneath the surface and you'll find a symbiotic relationship that might surprise you. According to Alaskan biologist Anne Post, the very act of growing sets up salmon to become ideal nutrient carriers for the trees the grow near the banks of lakes and streams.
To mature, salmon must move from nutrient-poor freshwater environments to seawater locations, which harbor plenty of food sources. After several years of growth, the salmon return to their freshwater homes, carrying all kinds of nutrients necessary for tree growth. For example, just one chum salmon offers an average of 4.6 ounces (130 g) of nitrogen and .7 ounces (20 g) of phosphorus. These nutrients -- and plenty of others -- supply nearby trees when the salmon die.
For their part, the trees give salmon a lot of help throughout their lifetimes, in a variety of ways. For example, insects make their homes in fallen leaves, and salmon dine on the insects. The trees also provide shade, which keeps salmon eggs cool, and even their roots help maintain the ecosystem by slowing erosion and helping keep waters clean.
As Post says, anyone enjoying a salmon dinner should remember to thank a tree, and if you come upon a beautiful and huge Sitka spruce while hiking, remember that a fish helped make it happen.
The surprising salmon:
- Salmon change color as they age; for example, a sockeye salmon can go from being pale with spots to silvery blue to bright red.
- The name "salmon" is believed to have come from the Latin word "salmo" or "salire," which means to leap -- just as the fish do in rivers on their way to spawn.
- While most Atlantic salmon grow to between 7 and 12 pounds (3 to 5.4 kg), the largest ever caught weighed in at 105 pounds (47.6 kg).