15 January 1979
Letter from Freshwater Fisheries (Concerns over Amitrole Spraying)
Further to your enquiry as to the Division’s attitude towards the use of “Amitrole” (3 amino 1-2-4 triazole) to eradicate blackberries from the margins of the Tarra River, I now advise that the Division would want to know a lot more about the proposal before making a definitive statement.
This compound is a known goitrogen (depresses thyroid activity) and its use in the USA is very restricted for that reason. In fact, the State Rivers and Water Supply Commission (on advice from the Health Department) does not use this material at all in Gippsland for the same reason, although it is used by the Commission in other parts of the State.
I understand that this compound may also have the potential to affect aquatic life, including fishes, at quite low levels (less than one part per million).
In view of the importance of the Tarra River for fisheries, for water supply, and in relation to Corner Inlet itself, the proposed use of this compound is a matter of some concern. In addition, I understand that the proponents of the eradication attempt are contemplating the use of heavy equipment along the stream margin, which may have important consequences for stream fauna and water productivity. As I am sure you are aware, there is general agreement amongst Government Agencies (confirmed by the Land Conservation Council in many instances) that the integrity of stream margins should be maintained wherever possible.
I would be grateful if you could relay to the people concerned the Division’s view that, from what we know of the proposal, there are real grounds for concern about possible implications of the proposal in a number of areas. The Division would appreciate an opportunity to comment further on the matter in due course, especially when more detailed procedures are planned…