What makes salmon swim upstream

Most species of salmon die after mating and making the migration upriver. Why is this? Most experts believe it is because the trip takes every ounce of energy the salmon have to make it. Every year some salmon do survive to come back to the ocean, however. There are 5 main types of salmon that swim upstream to spawn. The two most common species of salmon targeted by sports fishermen are king salmon and coho salmon.

King salmon can be identified by their large size, silvery sides, and dark greenbacks. They also have small black spots on their tails and the upper half of their bodies.

King salmon usually grow larger than the other species up to an average of 20 to 25 lbs. Coho salmon are the other most common species of salmon and look almost identical to king salmon. Coho salmon often only grow to 10 or 15 lbs. The easiest way to tell the difference between the two is to look inside their mouths for differences.

King salmon will have black gums and a black lower jaw, while coho salmon have white gums and a white lower jaw. Sockeye salmon are also smaller than king salmon, growing to an average of 10 lbs as adults. Sockeye salmon are the third most prevalent salmon species behind pink salmon and chum salmon.

They live in similar environments as the other species and also migrate upriver to spawn. Pink salmon are another common species of salmon that swims upstream, and only grow to be 5 lbs in weight.

Each year huge schools swim upriver in the pacific northwest every other year to spawn. Pink salmon are also called humpback salmon due to the physical changes the males go through when spawning. They grow large humps on their backs and turn bright pink before dying. No pink salmon survive after they swim upstream. Chum salmon are probably the least targeted species by sports fishermen, but they also migrate upriver to spawn.

They grow larger than pink and sockeye salmon, with their average adult weight clocking in at around 12 to 15 lbs. Now that you know why salmon congregate in mass numbers each fall, you probably want to know how you can catch them.

There are many different ways to catch salmon. If you want to learn more check out the articles we linked above. Very few salmon actually survive. Most Pacific Salmon die after depositing their eggs — these fish become an important source of food and nutrients for the local ecosystem.

Toggle navigation Menu. Explore Videos Games. Explore All. For salmon, laying eggs is a dangerous adventure. Salmon are born in freshwater rivers, spend most of their lives in the ocean and then return to the place they were born to lay their own eggs.

Salmon swimming upstream is both a form of migration and a way to ensure that their young survive long enough to hatch and grow into adults. The journey is challenging but leads to the successful salmon populations that animals and humans depend on for food. The main reason salmon swim upstream is to ensure the survival of their offspring. This fish spawning habit is what leads to the salmon passing down their genes successfully. As young salmon hatch in their home stream, they learn the smell of it.

As they migrate downstream and into the ocean they may even memorize certain scents along the way. Even after being away for many years, when these salmon return to their birthplace as adults, they will use those smells to "test the waters" and find their home stream.

If they swim up the wrong river, the familiar scent will fade and they will head back down to test another stream.

To prepare for spawning, the female salmon will create a depression in the riverbed using her tail. The female salmon then covers the redd with gravel before moving on to create a new one. A single female salmon can lay between 2, and 7, eggs and create up to seven redds.

Hundreds of thousands of us used to migrate from the Atlantic Ocean to the rivers where we hatched to spawn new generations of salmon Figure 1. Only small numbers of us return to North America now, mostly to Maine and eastern Canada. Our numbers are very low primarily due to dams and overfishing.

Our Gulf of Maine population Figure 3 is endangered. People are helping us by removing or modifying dams so we can reach our spawning grounds.

And our smaller numbers are being supplemented by national fish hatcheries. We are fished by commercial fisherman out in the ocean, but no recreational or commercial fishing is allowed once we have returned to our rivers in the United States. Fishing for landlocked Atlantic salmon is allowed.

Figure 1 — Atlantic salmon travel thousands of miles to their North Atlantic feeding grounds arrows , usually near western Greenland. They remain for one to three years before returning to their home river to reproduce. Figure 2 — Atlantic salmon bury their fertilized eggs under a foot of gravel in nests called redds.