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Hopeful Early Dioxin Test Results On Some Recreational Fish Species

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There are hopeful signs that the dietary advice on some pelagic species of fish in some parts of Sydney Harbour could be changed with dioxin tests on some species continuing to return relatively low results.

With almost 20% of tests on species of fish completed, dioxin levels appear to be well below the elevated levels found in bream and prawns, although the figures in other bottom feeders like mullet and squid continue to be high.

Early batches of preliminary test samples indicate that species of fish like Yellowtail, Kingfish and Trumpeter Whiting have much lower levels of dioxin.

Of 70 fish samples taken so far, 11 had dioxin levels higher than those recommended by the expert panel.

Early results from tests on a range of species in Port Jackson, east of the Bridge, including Sand Whiting, Kingfish, Luderick and Flounder have levels below the 6 picograms per gram recommended by experts.

All Yellowtail tested at Balmoral, Roseville Bridge and Manly were below 3 picograms (a picogram equals a trillionth of a gram). All Trumpeter Whiting were below 4pg/g, at Bantry Bay all Trumpeter Whiting samples were below 0.69 pg/g.

All Sand Whiting tested at Rose Bay and Chowder Bay were below 3.79 pg/g while Trevally tested at Quarantine Bay were below 2.52 pg/g.

The dioxin problem in the Harbour comes from sediment in areas like Homebush Bay, a legacy of 100 years of industrial pollution by companies like Union Carbide.

As a result, the dioxin levels remain high in travelling 'bottom feeders' like bream, prawns, mullet and squid.

For comparison with the most recent tests, bream caught at Balmoral in the December round before the Harbour was closed averaged 14.7 pg/g, bream caught at Clifton Gardens averaged 25.5 pg/g.

Bream caught further west, at Homebush Bay (which has been closed to commercial fishing since 1989) had an average reading of 95.6.

These readings are well above the panel recommendation of 6 pg/g – and that’s why the harbour was closed to commercial fishing in January.

The tests are not complete – and some of the pelagic fish caught have higher levels, for example two Yellowtail samples from Rushcutters Bay had readings of 9.8 and 9.5.

The results for bottom feeders like squid and mullet continue to be high – not surprisingly mullet from areas west of the Bridge like Brays Bay and Homebush have readings of 192, 182 and 147.

Fishing bans have been in place in problem areas in the upper Parramatta River for many years to protect the health of the general community.

This is good news for recreational fishermen but it is the “bottom feeders” that make up the vast bulk of the commercial catch so it can make no difference to the ban on commercial fishing in the Harbour.

The highest results are in bream, prawns, mullet and squid – bottom-feeders and the bulk of commercial catches.

Commercial fishers had been offered a $5 million buyout package for their industry – which had an annual value totalling just $217 000 a year.

Twenty-eight commercial fishers have accepted the Government’s offer – discussions are continuing with others.

The Government has been more than fair with its package – and if, in future the Harbour is re-opened to commercial fishing these fishermen will get the first option.

The dietary advice provided to recreational fishers will be reviewed once the final results are in and DPI receives advice from the Food Authority’s Expert Panel charged with assessing the data.

The State Government is currently conducting remediation works to clean up the former Union Carbide site at Homebush Bay.

Sydney Harbour was closed to commercial prawn fishing on December 3 and commercial fishing on January 24 after expert tests revealed high levels of dioxin in bream and prawns. Areas of the Harbour west of the Bridge including Homebush Bay have been closed to commercial fishing for more than a decade.

Almost seventy signs have been placed around the Harbour warning recreational fishers of the current dietary advice.

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