One of the amazing sights of the world, the annual Sockeye run happens each summer when, drawn by natural forces, the salmon return to the rivers which gave them birth. They fight their way upstream against powerful currents, waterfalls and rapids, determined to spawn. Sockeye typically stick to rivers with a tributary to a lake. Once home, sockeye lay thousands of fertilized eggs in the gravel and promptly die, their carcasses providing food for bears, otters and eagles and returning nutrients to the rivers and rainforests for the next generation of salmon. Over months, a salmon embryo develops an eye, hatches into an alevin, which carries a yolk sack for food, and then becomes a free-swimming fry. Sockeye remain in lakes for one to two years, feeding and learning survival skills, before heading to the ocean. They spend one to four years feeding in the Bering Sea and Gulf of Alaska, and then mysteriously find their way home to spawn and continue the cycle of life.