Sea bass falls in the low-fat fish category, with about 2 grams of fat per 100 grams of raw fillet. That puts it well below the threshold for what nutritionists consider a fatty (oily) fish. There’s an important exception, though: Chilean sea bass is a completely different species with a much higher fat content, and it does qualify as a fatty fish.
How Fish Are Classified by Fat Content
Nutritionists group fish into four categories based on the percentage of fat in their flesh. High-fat fish contain more than 8% fat (salmon, mackerel, herring). Medium-fat fish fall between 4% and 8%. Low-fat fish sit between 2% and 4%. Lean fish have less than 2%.
Standard sea bass, including European sea bass (branzino) and black sea bass, lands in the low-fat range at roughly 2.6 grams of total fat per 129-gram portion. It carries a “low fat” designation in USDA nutrition databases. So if you’re looking for a classic oily fish to boost your fat intake, regular sea bass isn’t it.
The Chilean Sea Bass Exception
Chilean sea bass (actually called Patagonian toothfish) is a completely different animal, both biologically and nutritionally. Its flesh is rich, buttery, and high in oil, which is why it’s nearly impossible to overcook. A 100-gram portion of Chilean sea bass delivers roughly 2,430 milligrams of combined EPA and DHA, the two omega-3 fats linked to heart and brain health. That’s comparable to salmon and puts Chilean sea bass firmly in fatty fish territory.
Regular sea bass, by contrast, provides between 500 and 1,000 milligrams of omega-3s per cooked 4-ounce serving. That’s a respectable amount, roughly on par with Alaskan pollock and albacore tuna, but far less than what you’d get from salmon, sardines, or mackerel, all of which exceed 1,000 milligrams per serving.
Nutritional Profile Beyond Fat
Even though regular sea bass is lean, it packs a strong nutritional punch in other areas. A single ounce of raw sea bass provides about 15.7 grams of protein and 31 micrograms of selenium, a mineral that supports thyroid function and acts as an antioxidant. Scaled up to a typical 4- to 6-ounce serving, that’s a substantial amount of both nutrients.
Branzino (European sea bass) and striped bass are also good sources of vitamin B12 and iron. Chilean sea bass adds high levels of vitamin D to the mix, a nutrient many people don’t get enough of, especially in winter months.
How Sea Bass Compares to Salmon
Salmon is the benchmark most people think of when they hear “fatty fish.” Atlantic salmon contains roughly 12 to 13 grams of fat per 100 grams, about five times more than regular sea bass. Its omega-3 content exceeds 1,000 milligrams per cooked serving, placing it in the top tier alongside mackerel, herring, and sardines.
Regular sea bass sits a tier below, in the 500 to 1,000 milligram range. That’s still meaningful for heart health. The American Heart Association recommends eating fish at least twice a week, particularly fatty fish, to get adequate omega-3s. If you prefer the milder taste of sea bass over salmon, eating it regularly still contributes to that goal, just less efficiently per serving.
Mercury Levels Worth Knowing
Regular sea bass (black and striped) has a mean mercury concentration of 0.167 parts per million, which is relatively low. Most people can eat it several times a week without concern. Chilean sea bass is a different story, averaging 0.354 ppm with some samples reaching as high as 2.18 ppm. That places it in the moderate-to-high mercury range, so limiting Chilean sea bass to a couple of servings per week is a reasonable approach, especially for pregnant women and young children.
Choosing the Right Sea Bass for Your Goals
If your goal is a high-omega-3, high-fat fish and you specifically want sea bass, Chilean sea bass delivers. It rivals salmon in omega-3 content and has a rich, forgiving texture that works well for people who find leaner fish too dry. Just keep mercury in mind and don’t make it your everyday protein.
If you’re looking for a lean, high-protein fish with moderate omega-3s, standard sea bass (branzino, black sea bass, or striped bass) is an excellent choice. It’s lower in calories, lower in mercury, and still provides a useful dose of omega-3 fatty acids along with selenium, B12, and iron. Pairing it with other omega-3 sources throughout the week, whether that’s salmon, sardines, walnuts, or flaxseed, covers the gap.