The Secrets of Salmon

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This week I watched a video titled The Life Cycle of Salmon and it proved to be an insightful topic. It provided me with a quick summary of the different stages a salmon encounters during their lifetime. The six stages discussed are as follows: 

1. Fertilized egg stage – Every salmon starts out as an egg in a gravel bed in a freshwater river or creek. These eggs will “incubate” for a certain amount of time depending on the type of salmon and the temperature of the water.

2. Sac Fry stage – Once the egg hatches, the salmon enters the yolk stage. These fish are small and remain in the gravel beds safe from predators. Salmon at this point have a yolk sac attached to their bodies and that sac feeds them until they enter the next stage.

3. Fingerling stage – This stage begins once the salmon leaves the gravel beds where they were born. How long a salmon stays in the fry stage depends on the species – some are only there for a short time while others will stay for up to a year.

4. Smolt stage – Once temperatures change and daylight hours are perfect, the fingerlings enter the smolt stage. Fish in this stage are growing quite rapidly. They typically stay in the brackish waters at the mouth of a river. Again, how long they stay in this stage and how big they are varies by species. Once the salmon reaches a certain size, they are ready to migrate into the open ocean and begin their adult life.

5. Adult stage – Salmon are considered “adults” when they complete the migration from freshwater to saltwater. They will feed in the open-ocean for a certain length of time depending on the species.

6. Spawner stage – At a certain point, the salmon will begin migrating back to freshwater where they enter the spawner stage. Salmon in this stage undergo physical changes, including changes in their color.

Amazingly, salmon in the spawner stage will migrate back to almost the same exact spot where they were born. Can you imagine what is needed to make this happen? Salmon not only have to have the physical ability to transit from fresh to salt water, they have the ability to recall exactly where they were spawned. As amazing as this is, it can only occur if they have the ability to reach these historical spawning site. A simple silting in of a tributary as a result of poorly managed erosion control on a construction site could impact thousands fish and future salmon levels. A poorly constructed culvert or a dam constructed by a farmer to increase water stores available can have a detrimental impact on this process. The bottom line, this process is amazing, these fish are superstars but small changes in this process can have a longstanding impact on fish populations. Drop in fish populations will create more than frustrated fishing fans or broke commercial fisheries. Weak fish populations impact the entire ecosystem they are part of.For example,  predatory birds and mammals would have reduced food sources. Riparian corridor insect populations may increase due to less feeding from fish.  These two examples would start changes in the water and food cycle of the riparian corridor. We all need to be educated, informed and aware of the impact we have on this process and our ability to influence change in a positive and productive manner.