No other creature can change the Earth just through that act, except for this one.
Scientists from the University of Idaho and Indiana University have published a study in the journal Geomorphology. According to this study, every time this creature enters its breeding season, it can significantly impact the Earth. What is this creature? Why can it put our planet in danger?
The Fish Born in Rivers and Living in the Sea
The creature we are referring to here is the salmon (scientific name: Salmonidae). The name “salmon” originates from the Latin word “salmo,” which is derived from “salire,” meaning “to leap.”
These fish inhabit the coastlines of the North Atlantic and Pacific Oceans. Thus, salmon are divided into two types: Salmo (Atlantic salmon) and Oncorhynchus (Pacific salmon).
Recent research shows that every time it’s time for them to breed, they actually cause the entire Earth to tremble. Their power, developed over millions of years, can… shift mountains and fill valleys, alter the geological characteristics of the areas where they spawn, and even contribute to the evolution of their species.
Salmon can “move mountains and fill valleys.”
Salmon have a unique characteristic compared to many other fish: they are born in freshwater areas like rivers and streams, migrate to the sea, and then return to freshwater to spawn. Female salmon lay their eggs in nests at the bottom of rivers, where they will incubate for several months. Once the eggs hatch into fry, they swim around the nest to feed. When they reach a length of about 15 cm, the salmon will swim out to sea. It is estimated that only 10% of salmon eggs survive to this stage.
Once mature, salmon will migrate to the sea to settle for 1-3 years. (Photo: Phys)
After a long journey of thousands of kilometers, salmon move to the sea and settle for about 1-3 years. The chemical composition of their bodies changes, allowing them to live in saltwater. When it’s time to spawn, salmon swim upstream back to the rivers where they were born to produce a new generation of salmon. Scientists believe that the reason salmon can return to the exact river is due to their olfactory memory.
It can be said that the journey of salmon overcoming numerous hardships to return to their “old home” is considered one of nature’s most remarkable phenomena. They must leap higher than the flowing water to overcome high waterfalls. Not only that, but they also need to swim as fast as possible. Even though salmon continually face failure and are swept away by the water, they never lose hope and keep jumping until they succeed.
If they are lucky enough not to be eaten by bears, wolves, or eagles, the salmon will have the chance to swim upstream another 1-2 times to complete their reproductive mission.
As impressive as this may be, scientists argue that the breeding season of salmon is the reason the Earth is affected.
Why Every Time Salmon Breed, the Earth Trembles
First, we need to understand that the breeding act of salmon is not the same as that of other animals. Females lay eggs, males release sperm into the water, and then the eggs are fertilized. The females rub against the banks to create nests and lay their eggs there, which is also the reason the Earth’s topography can change.
Scientists have attempted to model the impact of sediment movement on rock layers, forming the landscape of entire regions over millions of years. The results showed that one of the biggest contributors to this process is the migration of salmon.
When creating nests, salmon inadvertently lower the slope of the water flow, making both riverbanks more susceptible to erosion. Interestingly, the erosion rate increases, and sand and gravel are more easily washed downstream. Gradually, the topography of the entire area will change.
“Salmon not only cause sediment layers to shift” – quoted Alex Fremier, the study’s lead author. “They change the characteristics of the streambed, so as the water flows, the amount of soil, sand, and gravel carried away increases.” As a result, the underlying bedrock is gradually exposed, increasing the erosion risk for the entire area.
Salmon swim upstream to find a place to mate.
Additionally, it is important to note that different salmon species will have varying impacts on topography and the environment. For example, Chinook salmon (the largest species in the Pacific) can accelerate erosion processes in the same timeframe compared to smaller fish because they carry a significant amount of sediment.
With this research, experts understand that a single species can still have a profound impact on topography, landscapes, and the environment. The presence of every species plays a crucial role in nature.
The study was conducted by scientists from the University of Idaho and Indiana University, published in the journal Geomorphology.
