Fish are an important part of a healthy diet. They are high in protein and other essential nutrients, low in saturated fat and contain omega-3 fatty acids. In general, the benefits of eating fish greatly outweigh any risks.
However, people who fish in the Lower Yarra and Maribyrnong rivers need to be careful about eating their catch. The risks of eating your catch can be reduced if you make sensible choices about the type and amount of fish you eat.
Ask your council for advice in other areas
This fact sheet offers advice to people who fish in the Lower Yarra and Maribyrnong rivers. If you fish in other waters, please contact your local council for information and referral.
Polluted waters – the risk of PCBs
Over time, urban waterways can become polluted with chemicals. Fish may take up some of these chemicals into their bodies. There are a number of chemicals that can build up in fish. The main ones that can be a problem in the lower Yarra and Maribyrnong rivers are polychlorinated biphenyls (PCBs).
PCBs were used from the 1930s to the 1970s in industrial products. They have now been phased out, but they stay in the environment for a long time. Mercury may also be found in certain Victorian inland waters where it was once used for gold extraction. Mercury can remain in the environment for a long time.
PCBs can build up in the human body. If a person eats large amounts of contaminated fish, the PCBs may affect their health. Women who are pregnant or may become pregnant are the most likely to be affected. PCBs in a mother’s body can affect the development of her unborn baby’s brain. Young children are also at increased risk.
Health effects of PCBs
Some of the known health effects of PCBs include:
- learning problems and developmental delay in children
- skin complaints such as acne or rashes
- liver problems
- changes to the immune system
- changes to the hormone system, including impaired functioning of the thyroid gland.
Eels pose the greatest risk of PCBs
Chemicals such as PCBs tend to concentrate in the fatty parts of a fish’s body. Eels have a higher fat content than other fish and so tend to carry higher amounts of PCBs.
In a 2005 study of contaminants found in fish from the Lower Yarra and Maribyrnong rivers, two in every 15 eels exceeded the maximum safe limit of PCB levels.
The same study found that black bream were also high in PCBs compared to other species of fish. Mullets were found to have comparatively lower levels of PCBs than eels and black bream.
Reduce the risks of consuming PCBs
Risk reduction tips include:
- Women of childbearing age and children aged less than 16 years should not eat caught eels. Everyone else should limit eating the eels they catch to one serve per month.
- Women of childbearing age and children aged less than 16 years should limit eating caught fish to one serve per month. Everyone else should limit eating the fish they catch to four serves per month.
- The above recommendations apply to 150 g serves of fish. Weigh your fish portions to make sure you are not exceeding 150 g per serve.
- Try to eat smaller, younger fish, as these are likely to have fewer pollutants than older, larger fish. However, make sure the fish are within legal size limits.
- Clean and cook fish properly. Remove skin, fat and internal organs before cooking, because some chemicals concentrate in the fatty parts.
- Grill or bake fish instead of frying.
Remember that these precautions only apply to fish caught from the Lower Yarra or Maribyrnong rivers. These precautions do not apply to shop-bought fish.
Shop-bought fish and mercury
A well-balanced diet that includes fish can have lots of benefits for health, including heart health, and children’s growth and development. However, some fish you buy may have increased levels of mercury.
Mercury is a metal that can build up in the human body, and damage the nervous system and kidneys. If pregnant women have too much mercury in their body, their children may be at risk of learning problems and developmental delays. Generally, mercury from most fish sold in Australia is not a health risk for healthy adults and children, when eaten in reasonable amounts.
Fish that are predatory (eat other fish), large and are at the top of the food chain tend to contain more mercury. Pregnant women, women of child-bearing age and young children (under six years) should eat predatory fish such as shark (flake) or swordfish no more than once a fortnight. For the rest of the population, this is no more than once a week.
Health benefits of eating fish
Some of the many health benefits of eating fish once or twice every week include:
- lowered blood pressure
- boosted levels of ‘good’ blood cholesterol
- reduced risk of heart disease
- reduced risk of dementia.
Where to get help
- Your doctor
- Your local council
- Department of Human Services Victoria Tel. 1300 761 874.
- Environmental Protection Authority Victoria’s Information Centre Tel. (03) 9695 2722
Things to remember
- People who fish in the Lower Yarra and Maribyrnong rivers need to be careful about eating their catch.
- Industrial pollutants including chemicals known as polychlorinated biphenyls (PCBs) may be found in high levels in certain fish, including eel and black bream.
- This advice is for people who fish in the Lower Yarra and Maribyrnong rivers – contact your local council for information and referral if you fish in other waters.
This page has been produced in consultation with and approved by:
Department of Health and Human Services - RHP&R - Health Protection - Environmental Health Unit
Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your doctor or other registered health professional. Content has been prepared for Victorian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.