Wildlife officers have called for help from the public as they search for three entangled whales off the New South Wales coast.

The animals — two adults and one smaller whale — have been reported three times to the National Parks and Wildlife Service (NPWS) since Sunday.

Those who spotted them said they were wrapped in ropes and some had white floats attached.

"They may have shed that entanglement miraculously, but we're still likely looking for three entangled whales," NPWS spokeswoman Susan Crocetti said.

"When they're entangled, they can be quite unpredictable in terms of where we'll next see them."

The smaller animal is believed to be heading south, while the adults were moving north.

The sightings were recorded from Forster to Point Plomer, north of Port Macquarie.

It brings the number of entanglements this year to eight, compared to 21 from last year's migration season.

There have so far been eight entanglements in the 2018 migration season. ( Supplied: National Parks and Wildlife Service )

Ms Crocetti said the slight increase was "a bit alarming".

She said whales were known to become tangled in the gear associated with fishing traps, which include a rope from the sea bed to the surface.

"A whale that swims past might brush one of their [pectoral fins] against a rope and in the effort to move away from that, they get themselves entangled and they might try to roll or swim their way out and end up with this rope wrapped around themselves."

NPWS urged anyone who sees the animals to contact the Environment Line on 131555.

She said anyone who spots them should try to keep sight of them for as long as possible, and take photos.

"It's one thing to get a report but what we need is time to be able to grab our team … and get down onto the water so we can keep in contact with that whale and see if we can get it free," she said.