Common fish high in Omega-3s include: Swordfish, Atlantic Salmon, Silver Perch, Western Blue Grouper, Black Oreo, Blue Mackerel, Spanish Mackerel and Gemfish.

Shellfish generally aren’t as high in Omega-3s as the above fish, but the ones with the highest levels include Sydney Rock Oysters, Blue Mussels, Gould’s Squid and Blue Swimmer Crabs. All fresh seafood is nutritious, and many are a good source of omega-3 oils even if not as rich in them as those listed above, so eat a wide range of different seafoods and other natural foods to ensure a balanced diet.

FSANZ (Food Standards Australia New Zealand) has an online Food Composition Tables, listing the nutrient content of over 100 raw and prepared seafood products (including vitamins, minerals, fats and amino acids). They can help you determine which foods are the best sources of essential nutrients as well as which ones are major sources of nutrients you may want to limit (such as fat). And of course, there’s more than seafood, it contains data for over 2,600 foods (including common restaurant meals). 

Visit the FSANZ website and search the database or download a smaller printable version.

When prawns are harvested, enzymes in their bodies continue to function, leading to oxidation which forms black spots within a few hours without refrigeration; a similar reaction to the browning of fruits and vegetables such as apples and potatoes. Low temperatures slow – but don’t stop – enzymatic reactions, and refrigerated raw prawns develop black heads within a day or two if they are untreated. Most prawns are therefore either cooked (which denatures the enzymes), snap frozen, or dipped in a weak solution of metabisulphite (to slow the enzymatic reaction) as soon as they’re harvested. Increasingly, citric acid-based alternatives are being used to cater for people who are sensitive to sulphur. Farmed prawns are occasionally sold without being frozen, cooked or sulphured, though they do often start to show signs of blackening around the heads.