1979: North Heads Sydney. Pesticides and Heavy Metals detected in ocean fish. Pesticides:

Toxic Fish and Sewer Surfing
How deceit and collusion are destroying our great beaches

by Sharon Beder
first published by Allen & Unwin, Sydney, 1989

3. Toxic Fish

“…The second study by the Fisheries Research Institute was kept secret for years. Attempts by STOP, the Australian Conservation Foundation and by the then shadow minister or the environment, Tim Moore, to find out the results of the study were unsuccessful. In the study (shown in figures 3.4 and 3.5), which was finally published in an obscure Department of Agriculture report in 1987, (FRI, Part II, undated), blue groper and red morwong were collected between 1977 and 1979 near the ocean outfalls and tested for pesticides. Three of 40 blue groper specimens exceeded NH&MRC maximum levels for dieldrin. Ten of 58 red morwong exceeded the same levels for dieldrin and five had DDT body burdens in excess of NH&MRC maximum levels for total DDT. At least one red morwong had DDT levels that were 64 times the NH&MRC maximum levels and one had levels of dieldrin at 13 times the maximum levels. PCBS (polychlorinated biphenyls) were also detected in high levels and Although the Fisheries Research Institute claimed that these were safe levels (the NH&MRC have not set limits for PCBs in food), the levels exceeded overseas standards.

http://www.herinst.org/sbeder/Books/toxicfish/chapter3/ch3b.html