Customer query goes to the heart of some key distinctions among wild Pacific salmon species
by Craig Weatherby
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.
But there are significant differences among them in terms of total fat content and omega-3 content… and their varying fat levels also affect these fishes’ calorie counts.
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?
Here’s the response from Vital Choice founder and veteran Alaska salmon fisherman, Randy Hartnell:
While diet may play a minor role in the fat content of the several Pacific salmon species, diet has more to do with their vitamin D content.
(At about 687 IU per 3.5 oz/100 g serving, Sockeye salmon has more vitamin D than any other fish, and more than any other common food, by far.
Rather than diet, the variations in the body size and fat content of wild salmon have more to do with the birth rivers and preferred habitat of each species.
This table shows how wild salmon rank species we offer rank, 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:
|Salmon Species||Total Fat (grams)|| Omega-3s (grams)|
|Sockeye (red)||8.6 || 1.2|
|Pink (humpie)||3.5|| 1.1|
Click here to see additional comparative nutrition data... you will find full Nutrition Facts under the Nutrition Info tab located on 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 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 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, 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 specific characteristics of their home river.
For example, the Copper River is a relatively “steep” swiftly flowing river, so Sockeye and King salmon swimming against this current must have greater energy (fat) reserves than those returning to other rivers.
In contrast, Bristol Bay Sockeye and King salmon, which have a relatively easy migratory journey, may have half as much fat as their Copper River counterparts
By far the fattiest, richest King salmon of all come from the Yukon River, which is both the coldest and largest of Alaska’s salmon spawning rivers.
I hope this helps… let me know if you have any other questions!
Randy Hartnell, President
Vital Choice Wild Seafood & Organics