Wildlife Victoria volunteers are spending hours and sometimes days at a time, rescuing the swans with a significant number becoming caught up in South Morang, north of Melbourne, during the past few weeks.

This morning, volunteers responded to a struggling swan in the Hendersons Creek Wetlands.

"The swan had a lure stuck out of its mouth," Amy Amato from Wildlife Victoria said. "Someone had caught it, cut the line and done a runner."

Volunteers were able to remove the lure from the bird's mouth and, given the swan didn't appear too hurt, set it free immediately.

"There are a few swans out there who have cygnets and to take them away from the babies would be more detrimental," Ms Amato said.

Disturbingly, it's nowhere near the first time the organisation has encountered people abandoning injured swans. They even received a report recently about some kids intentionally trying to catch the swans.

"Because of these new estates, there may not be proper signage, or proper education around treating wildlife with respect," Ms Amato said.

Wildlife Victoria say it's people feeding the birds - often bread - that attracts them to the new suburban lakes.

And while bread is bad for the birds, once they're used to getting it they "come up to people thinking they're going to get fed and some people throw fishing line at them".

Feeding the swans is also detrimental to their independence.

"They're wild animals, to survive in the wild they need to forage for their own food," Ms Amato said.

In the South Morang area, 12 swans have become entangled in fishing line this year, compared with three for the same period last year.

Ms Amato acknowledges the numbers aren't huge but says the rescues can be lengthy. A swan caught in a fishing line with a hook in its foot had volunteers working every day for a week to set it free.

In the last 12 months, Wildlife Victoria have responded to 527 reports of wildlife caught up in fishing line or rubbish across the state.

If you find sick, injured or orphaned wildlife, please contact Wildlife Victoria's emergency response service on 1300 094 535 or visit their website www.wildlifevictoria.org.au.