All about salmon

September 11, 2025

3 min read

Not all salmon are the same. SWISS LACHS farms Atlantic salmon. But how many salmon species are there? What do salmon eat? And what are the biggest threats to wild salmon? In this article, we answer the most frequently asked questions.

8 answers about salmon

1. How many salmon species are there?

There are 9 different salmon species in total. The best-known species include king salmon, sockeye salmon, pink salmon, silver salmon and Atlantic salmon, which is the species farmed by SWISS LACHS. Most salmon species live in the temperate to subarctic regions of the northern hemisphere.

2. What do salmon eat?

Salmon larvae first feed on their yolk sac. Later, salmon eat insects, small crustaceans and both small and larger fish. You can learn more about what SWISS LACHS fish feed is made of in this YouTube video:
Watch the video

3. Why do salmon migrate?

At their birthplace in freshwater, salmon have only limited food. That is why they migrate to the salty water of the sea, where they find better conditions for growing and reaching sexual maturity. Salmon spend several years in the sea until they are fully grown. To spawn, which means to reproduce, they return to the place where they were born.

4. How do salmon find their birth river again?

Young salmon remember the chemical fingerprint of their birth river. Years later, they use this memory, together with their sense of smell and magnetic orientation, to find their way back to the exact place where they were born.

5. How do salmon adapt to freshwater and saltwater?

Salmon adapt through a process called osmoregulation. This process helps the salmon’s body adjust to changes in the salt level of the water. On the salmon farm, this process takes place in the brackish water tank. It is explained in detail in this video:
Watch the video

6. How many eggs does a salmon lay?

During reproduction, the female salmon uses her tail fin to dig a hollow in a gravel bed. She then lays up to 30,000 eggs in this hollow. The eggs are fertilised by the males. Afterwards, the female salmon covers the fertilised eggs with gravel again.

7. What role do salmon play in the ecosystem?

During their journey from the river to the sea and back again, salmon are an important food source for more than 200 animal species, including bears and birds of prey. They also help transport nutrients from the sea back into rivers and forests.

8. Why are wild salmon threatened?

River construction, pollution, climate change and overfishing have all contributed to wild salmon being considered threatened. Sustainably farmed and locally produced salmon can help reduce pressure on wild salmon populations and support their recovery.