Lismore resident and leisure kayaker Alex Clarke wants to know what is happening to the Wilson River.
When he kayaked down the river last week he felt like he was wading through sludge.
It was slimy and disgusting he said. The river is normally clean but now its covered with azolla and it looks like an oil slick. I kayak to relax and when you get on the river it feels like you are in a polluted environment. I havent seen it like this for years.
The sludge is actually azolla, a tiny fern found all over the world that multiplies when low rainfall slows the rivers flow, resulting in higher water temperatures and an increase in nutrients such as nitrogen that the azolla feeds on.
Robert Green is the Director of Earthmakers, an ecosystem repair company that consults nationally and also harvests aquatic weeds for fertiliser.
He said the azolla itself is not dangerous, it actually helps clean the water, however it is a precursor for the growth of more noxious weeds like water hyacinth and the highly toxic blue green algae.
He said the presence of water weeds is symptomatic of a sick river an Australia wide phenomena that needs to be addressed by everyone, from farmers to local water authorities.
He said the Wilson Rivers current state was made worse by run-off from farms, septic systems, roadworks and stormwater that runs unfiltered from the Lismore CBD.
Its no wonder (were seeing these problems ), he said. The river is really a drain.
Dr Leigh Davison, a Senior Lecturer in Environmental Science and Management at Southern Cross University said the azolla outbreak should be flushed out as soon as there was significant rain and that 100 ml within a couple of days in the upper catchment would be sufficient.
Meanwhile the Living Richmond River Group has grave concerns about what else could be in the river.
LRRG spokesperson Joe Friend claims there are complex organic and synthetic toxins entering the river that are responsible for declining fish populations.
The group bases its claims on findings from an independent scientific report he said they commissioned from Australian Laboratory Services in Sydney.
He said the report found that several toxins, such as ricin which is produced by the castor oil plant and trichlorfon, a chemical used in macadamia farming, could be poisoning the river and be responsible for local fish kills.
Mr Friend said his group wanted to test for these chemicals and was putting in a budget submission to Lismore City Council next week to ask for funding.
Council spokesperson Tony Kolhlenberg said they would consider the submission on a merit basis, but there were many other competing interests in the field of environmental health.
Mr Kohlenberg said Council did not test for the chemicals the group is concerned about because tests were both very costly and difficult to obtain accurate results on.
He said to do a random test in the hope of finding these types of chemicals would be searching for a needle in a haystack.
Mr Kohlenberg said Council did monthly tests for certain pollutants such as feacal coliforms and Ecoli and also conducted bi-yearly tests for some chemicals after heavy rain events, which he said was in line with other councils in the region.
He said the bi yearly tests had found some chemicals in the water, but at very insignificant levels.
Mr Kohlenberg said chemicals were not to blame for fish kills, which were caused by high water temperature and low oxygen levels.
Meanwhile the Wilson River is scheduled to come on line as the regions main water supply with the completion of the Lismore Source project in mid 2008. But thats another story. Stay tuned.
Update your news preferences and get the latest news delivered to your inbox.