The Swan River Trust recorded a sharp increase in rubbish collected from the Swan and Canning rivers during the second half of 1997, including a threefold increase in discarded syringes.

Between July and December 1997, the Trust collected 58 tonnes of general rubbish from the waterways, up 46 per cent from 40 tonnes during the same period in 1996. The increase represented an additional 18 tonnes of rubbish and was not attributed to any change in collection methods.

The number of syringes recovered increased from 52 to 158, while the number of drums rose from 16 to 41 and tyres from 43 to 61.

Water Resources Minister Dr Kim Hames said the figures indicated more rubbish was being dumped despite efforts by government and community groups to improve the condition of Perth's rivers. He was particularly concerned by the increase in syringes and said the amount of rubbish being discarded showed a lack of respect for the river environment.

The Swan River Trust was spending about $200,000 a year removing rubbish from below the high-water mark. Some drums recovered from the rivers had contained oil, fuel and other substances toxic to plants and animals.

The figures provide a useful snapshot of the rubbish problem affecting Perth's major waterways in the late 1990s.