Learning about a species spawning cycle is extremely important in increasing its sustainability where human contact is involved. This is doubly true for seafood species. In Alaska, it was discovered that not paying attention to the salmon's life cycle, for example was leading to severe overfishing. The problem griev so grave, in fact, that legislation was written into the 1959 Alaskan Constitution protecting the marine species being harvested from future annihilation and extinction. Today, these species are protected with a number of regulations, restrictions and guidelines placed upon Alaskan fisheries. Strict enforcement, blended with scientific knowledge have seen the remarkable regeneration of the salmon population in Alaska.
Salmon have a very interesting life cycle as far as the animal and marine kingdoms go, one that will take them from the icy Pacific waters to the rivers and streams of Alaska's wild frontier and back. Not only does this defy logic that a salmon would be able to find its way back and forth from the place of its birth within all the Pacific Ocean, but takes the salmon from salt water to fresh water and back. The salmon spawning cycle begins with eggs, laid in a stream bed. The hatchlings will make their way to the ocean, growing from alevin into smolts during the first several years of life. Next, the smolts group together, forming schools, and make their way to the ocean. A dramatic change in the salmon's body allows it to adapt to the salty water of the ocean. For several years the Alaskan salmon will explore the icy waters of the Bering Sea and Gulf of Alaska. Fully mature salmon will then head back to their birthplace to complete the spawning cycle and spawn themselves. After spawning, a mature salmon will only live a few weeks longer, and the decaying salmon body will provide nutrients for the stream, beginning the life cycle once again.
As evident by this spawning cycle, an adult salmon must pass through many phases before reaching the open water, where they are harvested for human consumption. This means that without careful planning, overfishing could easily occur. Other species that reach adulthood in a matter of months or even just a year are able to regenerate much more rapidly than salmon. Species that spawn right in the Pacific Ocean are also able to regenerate their populations more quickly, since there is no need for a period of travel or adaptation from salt to fresh water involved. When adult salmon are snatched from the Alaskan waters of the Pacific Ocean, they are never able to reach the place of their birth, meaning new salmon eggs or roe can never be laid.
In order to reserve this lifecycle, it is important that fisheries pay attention the quantity and qualities of the fish being caught. Close observation by fisheries combined with scientific research of the salmon lifecycle will continue to improve salmon sustainability. For now, the salmon spawning cycle will remain one of evolution's glorious, and delicious, mysteries.