Customer query goes to the heart of some key distinctions among wild Pacific salmon species
We recently received a question about the levels of total fat and omega-3s in various wild Salmon.
It comes up quite frequently and relates to nutritional distinctions, so we thought it useful to publish the query and our reply.
All wild Pacific salmon are rich in omega-3s, antioxidants, and vitamin D—factors that make them all exceptionally healthful.
One customer's fatty question
Why does king salmon have the most omega-3s of all types of salmon
Does it depend on where it lives and what it eats compared with the other kinds?
Randy Hartnell's response
Generally speaking, salmon that have more total fat will also have more omega-3 fatty acids, which constitute part of any fish's fat content
This table shows the fat and omega-3 content of the wild salmon species we offer, per 3.5 oz (100 g) serving. These are averages, because the nutrient content of individual salmon will vary within each species, depending on the year and their harvest location:
|Total Fat (grams)||Omega-3s (grams)|
Click here to our Seafood Nutrition Chart to see comparative nutrition data for select seafood species ... you will find product-specific data under the Nutrition & Ingredients tab of each product page in our Web store.
The omega-3 distinction
Omega-3 fatty acids can be thought of as the “anti-freeze” of the fat world, because these polyunsaturated fats remain fluid in fish that swim frigid ocean waters
This explains why omega-3s levels are usually highest in salmon that come from and return to the coldest rivers, and swim in the coldest ocean waters.
King salmon have the highest omega-3 levels of all Pacific salmon species in part because they favor deeper, colder waters during the ocean phase of their lives.
The total-fat distinction
While it may relate in part to water temperature, the distinctive total-fat content of each wild salmon species has a different explanation.
Pacific salmon stop feeding once they leave the ocean and begin to swim up their birth rivers against the current, so they must return from the ocean with sufficient energy (fat) reserves to sustain them during this strenuous final phase of their life cycle.
King salmon have evolved to favor larger rivers that require longer migrations, so they have the greatest need for stored energy.
Sockeye also tend to migrate further distances during the foodless, fresh-water part of their lives, so they often rank second to King salmon in terms of total fat content.
In contrast, pink and keta (chum) salmon spawn in estuaries, or small channels near them (respectively), so have the shortest migration and correspondingly lowest fat levels.
Silver (coho) salmon, which spawn in tributaries rather than lengthy rivers, occupy the midrange on the fat scale. (Interestingly, silver salmon are known for their jumping ability, which helps them surmount logjams and other obstructions common in small streams.)
Fat levels within individual species may vary dramatically depending upon the temperature, length, and steepness of their birth river.
For example, the fattiest, richest king salmon come from the Yukon River, which is both the coldest and longest of Alaska's salmon-spawning rivers.
In contrast, Bristol Bay sockeye and king salmon, which have a relatively easy migratory journey, may have only half as much fat as their Copper River counterparts.
I hope this helps… let me know if you have any other questions!
Randy Hartnell, President
Vital Choice Wild Seafood & Organics