Campbelltown Council has announced it will install signs at main fishing spots along the Georges River to educate fishermen about responsible use of fishing line, tackle, plastic bait bags, nets and traps.

The council plans to erect the signs at key points along the Georges River and at Menangle River Reserve on the Nepean River.

It also plans to mount a public awareness campaign about the platypus and the need to protect its environment through information on the council's website and the community newsletter.

The Georges River Combined Councils' Committee (GRCCC), together with the Macarthur branch of the National Parks Association, has backed the plan for greater awareness and is calling for tougher regulations on fishing equipment used in the waterway.

NSW Fisheries regulations say it is illegal to use any type of yabby or fish trap in the Georges River upstream of the Liverpool weir, as well as in any freshwater rivers, creeks and lakes east of the Newell Highway.

Labor duty MP for Campbelltown Walt Secord has put parliamentary pressure on the state government, asking whether it would consider erecting signs warning fishermen against the use of traps in the region's waterways.

"It is believed to be the first time in three decades that platypuses have been discovered in the Georges River near Campbelltown," he said.

Georges River Environmental Alliance member Sharyn Cullis said the platypuses should prompt the council to pay more attention to local waterways.

"The discoveries make Campbelltown the double-whammy of wildlife really, to have koalas and platypuses."

If you spot a platypus contact UWS koala expert Robert Close, pager 9962 9996 or the Advertiser, 4640 5151 or macarthuradvertiser.com.au.