Marine Life - Salmon Navigation Systems

//Journey to the Ocean//

Marine life is fascinating to me, researchers are constantly uncovering the many mysteries of the ocean and marine life behaviour is part of the giant riddle of the world under water. One of my previous blogs looked at how Haddock spawn were able to navigate the ocean with noticeable changes due to water changes. It seems there’s more than just going with the drift under the ocean and this applies to most marine life that have evolved and survived for thousands of years. Navigating and migrating around the world is a process that is common to be aware of but understanding how various species are able to orientate between A and B is something that continues to be a subject of research and curiosity.

//King Salmon//

Another aquatic life known as the King Salmon in Zealand or formally, Chinook salmon in other parts of the world has revealed just how it’s able to navigate the seven seas and freshwaters. Understanding the general life cycle of Salmon is most interesting as they roam the oceans for years before a homecoming to produce spawn. Various physiological changes will happen during this process and this is a calling that all Salmon will undertake at some point in their lives, typically during the colder months of the year. Returning home for a natural call to reproduce while navigating around the world has been theorised to involve the electromagnetic fields of our planet.

//Testing a Theory//

Magnetoreception is defined as the sensing of an organism that allows tracking and navigation around the planet by detecting the Earth’s magnetic fields. It’s seen in many migratory species that move around the world between seasons. It’s thought that Salmon and Turtles share similar magnetoreception abilities that work in tandem with other senses that may be chemical or other means. Testing the theory of magnetic field sensing, researchers were able to confirm their theory by proving pulses of magnetic waves from both a local and distant site. Simply put, this confirms that Chinook salmon and most likely other marine life are able to sense and navigate waters based on magnetic fields. Arriving back in freshwaters has been thought to leverage a chemical based navigation system and there is still much to be understood around the life cycle of this fish.

//Navigation and Homecoming//

Nature and life under water is amazing and the natural tracking mechanisms of the King salmon has been thought to be an adaptive one that activates when going out on a journey. I could compare this to loading up your favourite navigation app and setting place of origin and destination. The salmon are able to retain the coordinates of their home throughout the year and navigate ocean waters using magnetoreception. Their return journey is simply a return to their home coordinates and that can happen over the span of multiple years. As science continues to tests various theories, it may help to predict and monitor various species and perhaps even provide an avenue to help ensure their safety and sustainability.

Sources
https://jeb.biologists.org/content/early/2020/04/10/jeb.222091
https://en.wikipedia.org/wiki/Magnetoreception
https://en.wikipedia.org/wiki/Chinook_salmon