Pacific salmon begin hunting for food almost as soon as they hatch. Their bodies change to move from freshwater lakes and streams as juveniles to the salty oceans. What the salmon eat changes as well.
Researchers carefully study the diet of migrating salmon. This helps people who run hatcheries, like the Cook Inlet Aquaculture Association (CIAA), figure out the best way to raise young salmon in hatcheries. It also gives commercial fisheries managers insight into why salmon runs are stronger in some years than others.
Fish called salmon are truly amazing. They make amazing trips over thousands of miles, going from freshwater rivers to the open ocean. This migratory lifestyle exposes salmon to diverse food sources depending on their environment. But what do salmon eat in the wild that gives them the energy to make these long trips?
Wild salmon are opportunistic predators that feed on a wide variety of prey. When they are in their birth rivers and when they go out to sea, their diet changes a lot. The availability of food sources depends on location, season, and salmon species.
Let’s take a deep dive into the nutritious wild foods salmon consume throughout their life cycle:
Salmon Fry Feast in Freshwater Rivers
Salmon begin life in gravel nests dug out of riverbeds by spawning adults. After hatching, the tiny salmon fry stay in the river system feeding and growing for months or even years before heading downstream.
During this freshwater rearing stage juvenile salmon eat
- Aquatic insects – Mayflies, stoneflies, caddisflies
- Zooplankton – Microscopic animals
- Small fish – Minnows, sticklebacks
Insects make up the bulk of their diet, providing protein for rapid growth. Young salmon chase mayflies that are flying around, pull caddisflies from rocks that are underwater, and eat zooplankton that is drifting by.
Smorgasbord in the Sea
Once salmon transition from freshwater to the marine environment as smolts, their menu expands exponentially No longer limited to riverine bugs and fish, Pacific salmon feast on a rich diversity of ocean prey
- Herring – A favorite target, providing omega-3s
- Sand lance – Slender schooling fish
- Squid – High in protein and nutrients
- Shrimp – Full of pigment-providing astaxanthin
- Lanternfish – Abundant in the deep sea
- Krill – Packed with carotenoids
Salmon patrol coastal waters and migrate long distances in pursuit of dense schools of prey fish and protein-packed invertebrates. They gorge on energy-rich foods to fuel their long journey back to natal rivers.
Spawning Salmon Stop Feeding
As salmon return to their birthplace river to spawn, they cease feeding altogether. The dramatic change in diet is because:
- They no longer expend energy hunting
- Digestion would waste energy needed for spawning
- Freshwater prey cannot meet their high caloric needs
During the spawning migration or “salmon run”, adults survive solely on fat stores accumulated at sea. They use every last bit of energy to battle upriver, mate, lay eggs, and die soon after.
Young Salmon Fry Recycle Nutrients
After spawning adults die, the next generation feasts on their carcasses! Salmon fry recycle the marine-derived nutrients by:
- Feeding on decomposing flesh
- Eating nutrient-enriched salmon eggs
- Absorbing nutrients released into the water
This boost of ocean nutrients brought back by the adults gives the young salmon a healthy head start. The cycle continues as the fry grow large enough to migrate out to sea and replenish on a rich marine diet.
Ideal Wild Salmon Diet for Nutrition & Survival
Generations of salmon have evolved to take advantage of the most nutritious and plentiful foods in their habitat. Access to the right diet provides:
- Essential fatty acids for growth and development
- Pigments like astaxanthin for coloration and antioxidants
- High calorie intake to build energy reserves for the strenuous spawning run
Without these wild food sources perfectly adapted to each stage of their life cycle, salmon would fail to thrive, reproduce, and complete their iconic migrations between river and sea.
So while we love salmon for its flavor and nutritional benefits, its dietary flexibility and opportunism are key to the success of wild salmon populations across the Pacific Northwest!
What salmon eat in fresh water
When sockeye, coho, and king salmon hatch, they spend the first part of their lives in lakes and streams with fresh water until they smolt and get ready to move to the ocean. Pink and chum salmon don’t look for food in fresh water at this stage because they start moving to the ocean almost as soon as they hatch and absorb their yolk sacs.
Salmon raised by CIAA and released as fry find food in lakes and streams. They will eat about anything they can get their mouths around, including small insects and insect larvae, zooplankton, and small crustaceans called amphipods or scuds.
The salt water salmon diet
In the sea, salmon become predators, feeding on a wide variety of creatures. When salmon get out to sea, their main goal is to stay alive and eat a lot so they can get ready for their journey back to the spawning grounds.
At sea, salmon still eat zooplankton and crustaceans, which are similar to what they ate in fresh water. They also eat small squid, eel, and lots of shrimp.
In many ways, salmon become what they eat in the ocean. Consider the differences between coho, king, and sockeye fillets, particularly their color.
Carotenoids are a natural color found in many vegetables, like carrots, tomatoes, and pumpkins. They give salmon its pink or red color. Crustaceans such as shrimp and crabs contain high levels of carotenoids.
So it makes sense that crustaceans are the sockeye’s main food source, giving their flesh its unique red color. But coho and king salmon eat more than just crustaceans. They also like other small fish, which makes their meat more orange.
The Salmon’s Life Mission | Destination WILD
FAQ
What do salmon naturally eat?
Why do salmon stop eating in freshwater?
What do salmon eat the most?
What do wild caught salmon eat?
What do Atlantic salmon eat?
What Do Atlantic Salmons Eat? Atlantic Salmons’ diet includes larvae (from aquatic insects), terrestrial insects, and marine organisms like zooplankton, and a wide array of fish like herring, capelin, mackerel, and smelts. Atlantic salmon, also dubbed as the king of fish, can live in both fresh and saltwater.
What do salmon eat in the ocean?
When they’re in the ocean, young and adult salmon eat a wide variety of prey, including: Fish such as capelin, Atlantic herring, sand lance, barracudina and lanternfish. Crustaceans such as amphipods and euphausiids or “krill.”
What eats salmon?
Different kinds of predators feed on salmon at varying stages of their lives. Examples of these predators include some salmon species, other fish species, grizzly bears, polar bears, birds, snakes, whales, seals, dolphins, sea lions, and humans.
How do salmon eat their prey?
One technique that comes in handy for salmon when they are foraging for prey is suction feeding. Salmon, like other fish species, use suction feeding to attack their prey and proceed to suck them in their mouths. Following this predatory event, the salmon would then bite its live prey and further proceed to swallow.