I grew up in salmon country, and quickly developed a tremendous respect for these amazing fishes. Salmon are anadromous — they hatch in freshwater before migrating to saltwater where they live and grow for two to seven years, depending upon species, before returning to freshwater as adults to spawn. Why do they migrate to the ocean? Freshwater lakes, streams and rivers are nutrient poor. To grow big and to produce masses of eggs, salmon must have the abundance of nutrients that the sea provides.
When adult wild salmon return to their natal streams to spawn, they carry energy and a variety of nutrients in their bodies and after they die, these resources are transferred to animals and plants living alongside the stream. One of the most important of these nutrients is nitrogen. Because the particular form of nitrogen in air — nitrogen gas — cannot be assimilated by most organisms, it is usually a limiting nutrient for the growth of living beings. Nitrogen is a critically important component of amino acids, proteins and even DNA. It’s also a vital component of chlorophyll, which is used in photosynthesis by plants to make food.
READ MORE: https://www.forbes.com/sites/grrlscientist/2023/01/29/how-salmon-feed-wildflowers-and-transform-entire-landscapes/?sh=40dfdf9c3ff8