Questions and answers on dioxins in fish and crustaceans in Port Jackson
1. Why has commercial fishing been banned in Sydney Harbour?
A total ban was placed on commercial fishing in 2006 as a precautionary measure after test results revealed elevated levels of dioxin in a number of species of fish and crustaceans in Sydney Harbour.
2. What are dioxins and what effects do they have on humans?
Dioxins are a group of chlorinated compounds produced unintentionally by industrial processes, as well as through some natural processes, such as bushfires. Dioxins are found in low levels in the normal Australian diet and at these low levels present no known health risk. A recent national study concluded that the exposure to dioxins in Australia is generally lower than in other countries. Australian Health authorities have established a "safe" intake level of dioxin. This level has been set to protect individuals from health concerns including cancer.
3. Why are there high levels of dioxins in Sydney Harbour?
Residues of dioxins in seafood caught in the Harbour/Parramatta River are likely to have their sources in contaminated sediments in or near Homebush Bay. Current levels are likely due to many years of industrial activities along those waterways. Millions of dollars are being spent on cleaning up contaminated sediments in the affected areas.
4. What is the Government doing about protecting human health in the Harbour?
All commercial fishing is banned in the Harbour, including prawn trawling. Multilingual warning signs have been erected around the Harbour and a multilingual brochure is being distributed to warn recreational fishers of the dangers of consuming fish and crustaceans taken from the Harbour. Information is being provided to all one year and three year fishing fee receipt holders, fishing clubs, and charter boat operators.. Information is also being disseminated through FishCare volunteers, Maritime Officers, Water Police and through the Industry & Investment NSW (I&I NSW) websites.
5. Is recreational fishing banned in the Harbour?
Recreational fishing in the Harbour has not been banned, but fishers are urged to follow dietary advice on the consumption of seafood from the Sydney Harbour, Parramatta River and other connected tidal waterways. Fishers can also continue to practise catch and release.
Based on advice from an expert panel, the Government recommends that:
- No fish or crustaceans caught west of the Sydney Harbour Bridge should be eaten. You should release your catch.
- For fish caught east of the Sydney Harbour Bridge generally no more than 150 grams per month should be consumed.
- Testing of popular species has allowed for more accurate dietary advice.
The table below provides advice on the maximum consumption of single species.
Recommended maximum intake based on eating a single species caught east of the Sydney Harbour Bridge. |
||
|---|---|---|
Species |
Number of 150 gram serves |
Amounts per month |
Prawns* |
4 per month |
600 g |
Crab |
5 per month |
750 g |
Bream |
1 per month |
150 g |
Flounder |
12 per month |
1800 g |
Kingfish |
12 per month |
1800 g |
Luderick |
12 per month |
1800 g |
Sand Whiting |
8 per month |
1200 g |
Sea Mullet |
1 every 3 months |
50 g |
Silver Biddie |
1 per month |
150 g |
Silver Trevally |
5 per month |
750 g |
Tailor |
1 per month |
150 g |
Trumpeter Whiting |
12 per month |
1800 g |
Yellowtail Scad |
8 per month |
1200 g |
Squid |
4 per month |
600 g |
Dusky flathead |
12 per month |
1800 g |
Fanbellied leatherjacket |
24 per month |
3600 g |
Important Note: This advice is provided if one single species is being eaten. For example eating 150 grams of Bream and 600 grams of prawns in one month would exceed the recommended intake. Eating 300 g prawns, 300g sand whiting and 300g yellowtail scad in one month would equal the recommended maximum intake.
6. Will the Government be testing fish for dioxins in other estuaries?
I&I NSW acts on advice from NSW Department of Health and the NSW Food Authority on fish contamination issues. I&I NSW also acts on advice from DECCW on ecosystem contamination issues. When advised by these agencies, I&I NSW takes action by implementing fishing closures where appropriate, communicating health warnings where appropriate, and assisting these agencies with sampling of fish.
DECCW has advised that the type of manufacturing facility that was historically located in Homebush Bay producing particularly toxic chemicals (dioxins were unintentionally produced through this production) is the reason for the elevated levels of dioxins in the Harbour. These types of facilities were not located elsewhere in NSW.
7. Is it safe to undertake other recreational activities in the Harbour such as boating and swimming?
It is considered to be safe to undertake boating activities and swim in the Harbour. Water quality in the Harbour is the cleanest it has been in decades. The issue is with sediments on the harbour floor, which have been exposed to industrial pollution dating back over the past 100 years, and the migratory patterns of fish from polluted areas like Homebush Bay into the cleaner waters of the Harbour.
