Seafood and Your Health | Oceanwatch Australia

Seafood and Your Health

“The evidence is now largely unequivocal that some fish each week is an advantage to health and longevity”

Australians are encouraged to eat two to three serves of seafood each week.

Adult serve = 150g, child serve = 75g


Quick facts about seafood and your health

  • Fish does not lose its omega-3 health benefits by being canned

  • Seafood is the best food source of iodine. Saltwater seafood has about twice as much iodine as freshwater species.

  • Fish has long been recognised as a high protein, lowSet featured image calorie food.

  • It is becoming better understood that seafood can play a role in disease prevention.

  • Seafood is an excellent source of selenium and fluoride. Selenium helps prevent DNA damage from chemicals and radiation.

  • There is strong evidence that eating fish offers significant health benefits for the following conditions:

    • Coronary heart disease

    • High blood pressure

    • Irregular heart beat (arrhythmia)

    • Diabetes

    • Rheumatoid arthritis

  • There are promising results emerging for the benefits of fish to prevent or manage:

    • Bowel cancer

    • Asthma

    • Crohn’s disease

  • Eating seafood is also believed to help with neural development and memory, and may help treat or prevent depression and some types of cancer.The information provided here is general information only, and should not be considered medical advice. You should always consult your medical practitioner before dramatically altering your diet or planning pregnancy.

Seafood and Mercury

It’s good to eat fish, especially when pregnant or breastfeeding. Fish are a valuable source of protein, minerals, vitamin B12 and iodine. They are low in saturated fat and contain omega-3 fatty acids which are important for the development of babies’ central nervous systems before and after birth.

Most fish in Australia are low in mercury but too much mercury can harm developing nervous systems. It’s best to know the mercury levels of different types of fish and how often you should eat them.

Mercury occurs naturally in fish

Mercury occurs naturally in the environment and accumulates in the aquatic food chain, including fish, as methyl-mercury. All fish contain some methyl-mercury, but most fish in Australian waters have very low mercury levels.

Many fish have low mercury levels

The following fish have low mercury levels and are also high in omega-3 fatty acids:

  • Mackerel

  • Salmon

  • Canned salmon & canned tuna

  • Herrings

  • Sardines

Other seafood with low mercury levels include:

  • All prawns, lobsters and bugs

  • All squids and octopus

  • Snapper

  • Trout

  • Whiting

  • Herring

  • Anchovy

  • Mullet

  • Garfish

Canned tuna and salmon

It is generally safe for everyone, including pregnant women, to consume two to three serves of tuna or salmon a week, canned or fresh.

Canned tuna usually has lower mercury levels than other tuna because tuna used for canning are smaller species that are caught when less than one year old.

Crustaceans and molluscs

Crustaceans (including prawns, lobster and crabs) and molluscs (including oysters and calamari) are not a concern because they generally contain lower levels of mercury.

Breastfeeding mothers can continue to eat fish

Fish are rich in protein and minerals, low in saturated fat, and contain omega-3 fatty acids, which are important for the development of your baby’s central nervous system, even after birth.

Although it’s important to continue eating fish while you are breastfeeding, be careful about which fish you choose. Some fish may contain mercury levels that can harm a baby’s developing nervous system if too much mercury is passed on through breastmilk.

To safely include fish as an important part of a balanced diet while you are breastfeeding, follow the same guidelines provided to pregnant women.

Fish is good for young children

The healthy nutrients found in fish are excellent for growing children. Simply follow the guidelines for children up to 6 years.

Pregnant, breastfeeding women and women planning pregnancy
1 serve equals 150g
Children up to 6 years
1 serve equals 75g
Eat 2-3 serves per week of any fish and seafood not listed below
Eat 1 serve per week of these fish, and no other fish that week:
Catfish or Orange Roughy (Deep Sea Perch)
1 serve per fortnight of these fish, and no other fish that fortnight:
Shark (Flake) or Billfish (Swordfish, Marlin)

Mercury from fish is generally not a health consideration, it is mainly an issue for women planning pregnancy, pregnant women, breastfeeding women and children up to six years.

Ready-to-eat, chilled seafood, such as raw sushi, sashimi & oysters or pre-cooked prawns and smoked salmon can be risk for pregnant women because of listeria.

The information presented here is taken from Food Standards Australia and New Zealand, and the New South Wales Food Authority.

For more information visit these websites:

Seafood and omega-3

To reduce the risk of heart disease, the Heart Foundation recommends that Australian adults consume about 500 milligrams of omega-3 from marine sources every day. You can achieve this by eating two to three 150 gram serves of oily fish every week.

The Heart Foundation recommends that people with heart disease consume about 1000 milligrams of omega-3 (marine source) every day. You can achieve this by eating two to three serves of 150 grams of oily fish every week and by supplementing your intake with fish oil and omega-3 enriched foods and drinks.

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are omega-3s that are found primarily in oily fish, such as:

  • Australian salmon

  • blue-eye trevalla

  • blue mackerel,

  • gemfish

  • canned sardines, canned salmon and some varieties of canned tuna.

Other fish such as barramundi, bream or flathead, and seafood such as arrow squid, scallops and mussels, are also good sources of omega-3.

What is ‘oily fish’?

Oily fish are fish that contain at least 10% fat, most of which are the healthier omega-3 oils. In Australia, the oiliest fish include: canned salmon and sardines, some varieties of canned tuna, salmon, gemfish, blue-eye trevalla, blue mackerel, oysters and arrow squid.

How much omega-3 is in a piece of fish?

This varies widely depending on the fish that you are eating. A 150 gram serving of salmon or blue-eye trevalla may provide between 500 850 milligrams of omega-3, while the same size serving of ling may provide less than 160 milligrams of omega-3. A 150 gram serving of canned salmon or sardines may provide more than 2000 milligrams of omega-3.

The Heart Foundation recommends that you eat fresh, frozen or canned fish with the highest levels of omega-3s two to three times a week, and then add supplements and/or foods and drinks enriched with omega-3 as needed.

For the Heart Foundation’s list of fish and seafood with higher levels of omega-3s, see Omega-3 levels in fish and seafood at

This information is taken from the Heart Foundation’s Omega-3 Q&A. For more questions and answers on omega-3 and seafood, read the document here:

Scroll to Top