Whitebaiters use detergent, cooking oil to clean water

Dishwashing liquid might be useful for getting last night's spaghetti off your plate, but it isn't the quick fix to New Zealand's degrading waterways, Environment Canterbury says.

Environment Canterbury has warned against the use of detergent and cooking oil to improve water clarity, after whitebaiters around Canterbury were found putting these products into the water.

Environment Canterbury's principal surface water scientist Adrian Meredith says the fishers approached did not seem to be aware that the discharge of these liquids had big consequences for marine life.

"It is actually illegal to add these products into the water and could result in enforcement action, but more importantly, it could be very harmful to the river ecology and the fish that live there," Mr Meredith said.

"Most people are doing the right thing but for those that aren't, we ask them to stop this practice."

Environment Canterbury said they would be monitoring some whitebaiting spots but were relying on members of the public to take responsibility.