The NT Health Department put signs up warning people not to collect or eat any fish or shellfish caught in the Katherine River. 

About 30 signs have been erected at:

- High Level bridge boat ramp

- Galloping Jack's

- Cristal Rapids

- Low Level bridge

- Knott's Crossing

The Department of Defence updated residents on PFAS chemical contamination on Monday night.

Residents were cautioned not to eat fish caught in the Katherine River and other homegrown produce.

Fish found below the Stuart Highway bridge have been found with high levels of PFAS and anglers have been warned to avoid eating the fish as a precaution.