Six cygnets have been hatched and survived at the Berry Sewage Treatment Works detention ponds.

The Shoalhaven fox control program has been baiting on the Miller dairy farm, which surrounds the sewage works, for the past 10 months.

Program coordinator Peter Jirgens said the appearance and survival of the cygnets was significant.

"This is the first year that all the signets have survived, as fox predation was common," he said.

"One of our volunteers Andy Morgan took some wonderful photos.

"And one of the controllers who works at the site tells us it is the first time in many years the cygnets have survived.

"It's great to see and shows the program is working as they have survived.

Read more:

"We have put sensor cameras in the area and have also seen the return of other animals like bandicoots."

He said local farmer John Miller got involved in the program when it was also noticed foxes were preying on the long-necked turtle population that lays their eggs in the area.

"The long-necked turtles dig a hole and lay their eggs and let the sun incubate them," Mr Jirgens said.

"The foxes are attracted by the eggs and dig up and destroy the nests and eggs.

'We found five or six nests, each with between five and six eggs, that had been raided.

"It was more than 30 potential turtles that were destroyed.

"When John saw that he was keen to get on board.

"And now we are seeing the results with other animals also returning. And this year, so far, all the nests have remained intact."

Program volunteer Andy Morgan, from Gerringong, said it had been special witnessing the cygnets survival and growth.

"It's been pretty special to firstly see the six signets hatch and emerge with their parents, and then see them grow," he said.

"It's been fun.

"There area has a lot of birds out there but these are the only swans."